Ultimate Charger II by SAI

2000-2005

The Ultimate Charger II is designed as a single unit that can maintain the charge on 8 transmitters or receivers at a time. It can charge, trickle charge, and cycle nicad packs from 300 mah to 3000 mah capacity. The Ultimate Charger II constantly checks the packs and gives an audible warning when a battery pack is disconnected. The charger senses when the battery pack is removed for use, and switches back to fully charge the battery when the battery pack is reconnected. The precise voltage and capacity of all 8 packs is displayed on a 168 character graphic LCD. The Ultimate Charger is functionally very complex, but simple to operate. Several unique features are power backup by the 12 volt field box battery and, field box charging, special dynamic and float battery tests, interface to a home computer, and a Graphic display.

The display on the Ultimate Charger II is completely different from any other charger. I wanted this display to show all channels at once (168 characters), and even graphically display the charge and discharge voltage curves. The display became a 128 by 64 dot Graphic LCD. An LED backlit Graphic LCD for visibility under dark conditions is also available.

R/C batteries are used in 4 number of cells versions. Most airplanes use a 4 cell, 4.8volt pack. But high performance models are now using a 5 cell, 6.0 volt pack. R/C cars generally use a 6 cell, 7.2 volt pack, while all of the newer transmitters use an 8 cell, 9.6 volt pack. R/C receiver packs come in different sizes, from under 300 mah to over 3000 mah. The Ultimate Charger II will handle the following battery types.

4.8 @ 300 TO 3000 MAH, 100 MAH STEPS=28 steps

6.0 @ 300 TO 3000 MAH, 100 MAH STEPS=28 steps

7.2 @ 300 TO 2500 MAH, 100 MAH STEPS=23 steps

9.6 @ 500 TO 2200 MAH, 100 MAH STEPS=18 steps

This gives a total of 97 different battery types. A new system of 4 pushbuttons was devised so that the user could "configure" his charger to his exact situation. A special non-volatile memory chip was included to save the user's customized configuration.

The Ultimate Charger II is designed so that it can run by plugging it into a car's cigarette lighter, the 12 volt field box battery , or the 117 vac house voltage.

When an airplane is flown very aggressively, or even when landing, the servos are continually starting, stopping, and reversing; often several at a time. This puts a very heavy load on the battery. A special channel on the Ultimate Charger II is connected to an unused servo position on my receiver to monitor the voltage bus and executed a snap roll on the ground. The instantaneous voltage drop should be between .5 and 1 volt. Greater than this indicates a weak battery or poor wiring. This 1/5th second test is more meaningful to me than a 5 hour cycle test!

I believe that many of the unexplained crashes are caused by poor dynamic performance.

All of us have gotten to the field, only to find that the field box battery did not have enough power in it to start the airplane motor, especially if the motor was a bit balky. I programmed the Ultimate Charger II to take 96 measurements over a 1/5th of a second period while looking at the voltage coming from the Lead battery. I simply start my starter motor, and the Ultimate Charger II draws a graph on the LCD of how the 12 volt Lead battery drops under the load of the starter motor starting. A good battery and starter will show about 2-3 volts drop. An old or incompletely charged 12 volt Lead battery will show a much greater drop. A Starter with bad brushes, weak wiring, or a poor switch will show less drop or a very erratic starting pattern. A starter with more torque will show more drop. You can evaluate different starters in 1/5th of a second by simply performing the Lead Dynamic test on the Ultimate Charger II.

Another item that I have noticed is that batteries that tend to short out, all seem to have high self discharge rates. If you want to check the self discharge rate with the Ultimate Charger II, set the channel in question to "Float", and it will not put any charge into this channel, but will keep measuring the channel over many days to determine whether this battery pack is able to hold its voltage for a reasonable length of time.

The list of functions for each channel is now:

• FLOAT - No charge, just monitor the voltage self discharging.
• CHARGE - C/10 charge rate for 16 hours, automatically reducing to TRICKLE
• RAPID CHARGE - C/7.5 charge rate for 12 hours, "
• QUICK Charge - C/5 charge rate for 8 hours, "
• CYCLE Discharge @ 160 ma or 320 Ma, charge 16 hrs, discharge, charge....
• SINGLE CYCLE - Discharge, charge for 16 hours, reducing to trickle
• SINGLE CYCLE RAPID CHARGE - Discharge, rapid charge 12 hrs, trickle
• SINGLE CYCLE QUICK CHARGE - Discharge, quick charge 8 hrs, trickle
• Additional features are:
• Visual and Audible signaling of battery quality before use.
• Charges the 12Volt Lead Field box battery, auto switching for power line backup
• DYNAMIC Testing, graphing, & analysis of receiver packs
• DYNAMIC Testing, graphing, & analysis of the 12 Volt Lead Field box battery
• Keeps track of how long ago each channel was last cycled
• Keeps the MAH rating derived from the last 5 times each channel was cycled
• Charger graphic data can be sent from charger to IBM PC running Windows 95.

The Ultimate Charger is designed as a lifetime device. It is very conservatively rated. It was designed for worst case - all channels charging 1200 mah to 2200 mah packs for 16 hours, which is double the capacity of the original Ultimate Charger. In actual operation, most of the time the channels are on Trickle, which lightly loads the charger.

                                                                                          (Ultimate Charger 2 charging 1 transmitter,7 receiver/ignition packs                                                                                                                       & 12v Lead fieldbox battery)

Preparing the Ultimate Charger for Use

Initial Test

The back of the charger has 2 small holes. The hole nearest the SELECT key switch is for the power connector. The other hole is for the optional cable going to the PC. The power transformer's connector is pushed into the jack inside the Ultimate Charger II. Plug the transformer into a 117v 60 Hz socket.

The charger should beep & identify itself, display the charger functions, then go through the channels and display functions, eventually finding out that all channels are OPEN.

When you have determined that the charger is OK, so unplug the wall transformer & start wiring the charge cables to the Ultimate Charger II.

Attaching the Charging Cables

I have always used charging cables that soldered directly to the Printed Circuit Board (PCB). Some users wanted connector flexibility. They would sometimes make a Deans connector header into which they could plug a cable header which provide a JR transmitter plug, a Futaba transmitter plug, a JR receiver plug, or a Futaba receiver plug, etc. Many users pushed out the grommets and used some chassis mounting RCA pin jacks. They then wired the charging cables to RCA pin plugs that could be easily connected & interchanged.

I begin the wiring operation by determining exactly what I want to charge on each channel. Each channel is individually capable of being a transmitter or receiver of any size.

Attaching the cables to the Ultimate Charger must be carefully done!

If proper polarity is not observed serious damage to the charger and the transmitter or receiver could occur. However, the problem is easily avoided if a simple procedure is followed. Futaba and most other manufacturers use the standard color coding system of black is - and red is +, just like on your car battery. JR receivers and servos have red as + and brown as -. Then to really do it up in style, they made the transmitter jack and color code totally reversed, with black + and red -.

I find that the best way to get the polarity right is to make up the cable, and plug in the cable to the transmitter, airplane (boat or car). Then take a voltmeter and measure the voltage at the charger end of the cable, noting the polarity. The suggested speaker cable is color or insert coded, so note the color or insert coding of the - lead of the cable. Solder this lead to the - hole of the desired channel. Then measure the voltage by connecting the voltmeter - lead to the common ground bus of the charger's PCB, and the dangling + lead of the cable to the + lead of the voltmeter. Proper voltage polarity should be detected. Then unplug the cable from the battery pack and solder on the + lead of the charging cable to the + pad for the desired channel. Do this for all 8 nicad channels.

. Example: My Ultimate Charger II system has 2 JR transmitter cables soldered to channels 1 & 2. I connect the RED lead to the - side of ch #1 and the BLACK lead to the + side of ch #1. The second JR transmitter cable is soldered just like the first, with the RED lead to the - side of ch #2 and the BLACK lead to the + side of ch #2. The receiver pack cables have the BROWN lead to the - side of ch #3 or #4 or #5 or #6 or #7 or #8, and the RED lead to the + side of #3 or #4 or #5 or #6 or #7 or #8.

. Recheck your work several times before connecting the attached cables to the battery packs.

Connecting the Charging Cables Directly to the PCB

If you look inside the Ultimate Charger II at the area below the square white power resistors, you will notice the words CH1 to CH8 along with a - and a + sign on either side of a number. At the left side is the word "TEST" with a - and a + sign. At the Right side is the word "LEAD" with a - and a + sign. All of the - leads are connected to a common ground bus, and the + leads head up towards the charging and discharging current limiting resistors.

I keep my airplanes on racks in my garage, and the transmitters and charger on book shelving in the middle of the airplanes. Since my airplanes are mostly large airplanes, the usual charging cords are too short. I splice 20 gauge Radio Shack speaker wire (#278-1388) to the charging cord, covering the splice with heat shrink tubing (hobby/electronics stores or Radio Shack #278-1610. Female connectors for JR, Futaba, Airtronics, etc. are available at hobby shops or in bulk from Cermark (800) 704-6229. I use 5/16" grommets (included) pushed into the grommet holes to keep the insulation on the cable from chaffing against the metal. Push the grommets into their holes with a small screwdriver from the inside of the top cover to keep from scratching the outside of the top.

Cal Orr at Custom Electronics (888) 584-6284 sells a set of 4 unassembled female charging connectors for $10. Cal has the female charging connectors in JR, Futaba J, and Airtronics sizes. These can be crimped directly onto the speaker wire, eliminating the need for the splicing. The transmitter cables can be made from Radio Shack power plugs (# for JR and # for Futaba)

Connecting the Charging Cables to RCA pin jacks

The original Ultimate Charger came with the grommets already in the holes, but many people pushed them out and put in chassis mount RCA pin jacks (Radio Shack #274-346 or #274-852) in the chassis' empty grommet holes. They then wired up the various charging cables to RCA pin plugs (Radio Shack #274-451B or 274-383) that they inserted into the desired channel jack.

I do not like the RCA pin plug's exposed battery end. It could easily short out if still attached to a battery and touches some metal conductor across the end of the male RCA pin plug. If attached to a transmitter, this will blow the transmitter's protective 3 amp inside the transmitter, and keep you grounded until you find a new fuse. PREVENT THIS BY NEVER UNPLUGGING THE RCA PIN JACK FROM THE ULTIMATE CHARGER II WITH THE OTHER END ATTACHED TO A BATTERY!

Connecting the Lead Battery

The 12 volt field box battery can be connected to the Ultimate Charger II. The battery will be charged, and the battery will provide failsafe operation for the charger should the power line electricity fail. The charger does not need the battery for normal operation, but it's nice to know that even if electricity should fail, you will be fully charged tomorrow! The same leads going to the Lead battery can also be connected to a cigarette lighter plug instead, so that the Ultimate Charger II can be run from a car.

Your local Radio Shack store can provide all the wiring and accessories to produce a first class 12 volt system at minimal cost. Get the following Radio Shack items:

#270-025 DC Accessory Cable 4' long with fuse holder

#270-026 DC Accessory Extension Cable 1' long

#270-1011 Package of four 5 amp fuses

#270-021B Universal Lighter-Socket Power Cord 8' long

The Ultimate Charger II has a high current diode across its lead battery input line. If a reverse polarity 12 volt battery is connected, an external fuse must blow to protect the charger. Follow the directions below to set up a trouble free system.

The 4' cable system includes a polarized plug set with red & black wires on one side, and red & black wires with a fuse holder on the other side. Attach the side with the fuse holder to the Ultimate Charger II by cutting off the spade lug, twisting the black & red wires together, passing the wires through the grommet underneath the "LEAD" label, and solder to the PCB. Solder the red wire to the + LEAD pad and the black wire to the - LEAD pad.

Now solder the red & black wires from the other side of the polarized plug set to the field box battery. The red wire connects to the + terminal, and the black wire connects to the - terminal. Carefully check your wiring to make sure that you have everything correct.

Unplug the polarized plug set and put one of the 5 amp fuses in the fuse holder. Check everything a final time. Now with the wall power disconnected, connect the polarized plug set in the only direction possible. The Ultimate Charger II should start to run. If the fuse blows, you wired it wrong somewhere.

Disconnect the field box 12 volt battery. Take the 1' extension out of the package. Try plugging both polarized connectors into the polarized connector just attached to the charger. Notice that in one direction a black wire mates with a black wire, and in the other direction a black wire mates with a red wire.

Plug the polarized connectors together so that a black wire mates with a black wire. Now measure down the 1' long leads about 9" and cut off the non mating polarized connector. Unplug. Set aside this polarized connector for use on a spare 12 volt lead battery.

The non mating polarized connector will now be used to connect the cigarette lighter plug to the charger. The trick will be to splice the non polarized connector to the wires coming from the cigarette plug so that the center button of the cigarette lighter plug is connected to the + LEAD pad on the charger.

According to the drawing on the back of the cigarette lighter plug package, the ribbed lead on the cigarette lighter plug is positive. So, if you connect the ribbed lead to the BLACK wire coming from the non mating connector, the center button will wind up connected to the + LEAD pad. Use some of the heat shrink tubing over the splice.

But I would measure it very carefully with an ohmmeter, since I don't trust anything electronic!

Connecting the Dynamic Test Cable and Connectors

The dynamic test cable is designed to plug into an unused servo position on the R/C receiver's servo bus. It is wired to pick up just the + and - voltage at the receiver bus. The signal line is ignored.

A 3' long 2 conductor cable is included with the Ultimate Charger II. This cable goes through the 5/16" grommet underneath the "DYNAMIC" label on the front of the case and the black wire is soldered to the -TEST pad from the component side of the PCB. The red wire is soldered to the + TEST pad from the component side of the board.

The other end of the cable should have R/C connectors spliced to it. You really only need the male connector like the one on the end of your battery or servo, but I would suggest having both a male and a female battery/receiver connector for each brand of radio to be checked. I personally only have JR radios so I could get away with just a male servo connector on the end of the cable. But frequently friends at the field ask me to check their radios. They may have Futaba and Airtronics radios, plus a few other brands at our large field with 500-600 fliers.

I buy a 12" JR, a 12" Futaba, and a 12" Airtronics servo extension. Your local hobby store and Cermark, mentioned above, has these extensions. Cut each extension in half, so that you wind up with six 6" cables, 3 with a male connector, and 3 with a female connector. Now twist the six + voltage red wires together. Then twist the six - voltage black or brown wires together. The six signal wires can be left floating, as they are not used.

Now take the plastic sheathed dynamic cable attached to the charger and strip the outer plastic back about 1 ½". Then strip the red and the black wires about ½". Slide a 2 ½" long piece of larger heat shrink tubing over the cable sheath, and a 3/4" long piece of medium sized heat shrink tubing over the end of the red & the black wires. Twist the six + voltage red wires onto the red cable wire and solder. Twist the six - voltage black or brown wires onto the black cable wire and solder. Slip the two 3/4" long pieces over the solder joints and shrink. Slip the 2 ½" long piece over the whole splice area, tucking the signal lines alongside the voltage wires, and shrink. You should now have a very funny looking universal dynamic test cable.

Four rubber feet are included for attaching to the charger. Put them on the bottom pan's 4 corners if using the charger horizontally. I use my charger vertically, so I attach them to the front edge.

Initial Operation

Understanding How the Ultimate Charger II Works

Level 0 = Off:

Level 1 = Initialize: Initialize Memory, Display & Serial Port, and Display Message

Level 2 = Test all functions

Level 3 = Calibrate: Show version, Calibrate A/D channels

Level 4 = Operation: Show graphs, dynamically test Nicad & Lead, Charge/Discharge

Level 5 = Program: Set voltage, mah, & function of each nicad channel

Level 6 = Display: Select whether to view all 8 channels, 1 channel, or 8 channels rotating

Level 7 = Run: Check every channel's voltage, send charging & discharging pulses, display

The Ultimate Charger II will automatically go through the 7 active levels, with no user intervention, when turned on. Level 2 & Level 3 are maintenance levels that are not normally accessed by the user. If the user wishes to change the battery descriptions & activities, it is done at Level 5. If the user wishes to change how the charging activities are displayed, it is done at Level 6.

Level 0 = OFF

The Ultimate Charger II is designed to be customized by the user. Even when completely disconnected from the power line or any battery, a small Electrically Erasable Memory (EEROM) keeps critical pieces of data about the user's charging world alive inside the Ultimate Charger II.

Level 1 = Initialize

When power is applied to the Ultimate Charger II, either from the AC line transformer or from a 12 volt lead battery, the charger begins several internal activities needed to set everything to a known initial state. When everything is ok, the microcontroller sounds the beeper to indicate completion of the initialize function, and then puts a message on the Graphic LCD saying "ULTIMATE CHARGER II" in large letters. The microcontroller proceeds through the Level 1 software automatically and winds up eventually in the next step, OPERATIONS, Level 4. Should the software later ever get completely lost, the microcontroller's internal "watch dog timer" will reset itself to the beginning. However, it will find that it does not need a complete reset, so will do a minimal initialize, skipping the beep & the message, winding up at Level 4.

Level 2 = TEST

This Level is accessed by hold down the "ENTER" key while powering up the charger. This level is used during manufacture to exercise the various functions of nicad charging, nicad discharging, sending a graph to an attached PC, setting the lead battery charging voltages and calibrating the 12v power supply.

Level 3 = Calibrate

VERSION 04-29-98

DYNAMIC CHAN IS 0.0V

9V BATTERY IS OPEN

12V LEAD BAT IS 14.1V

24V CHG BUS IS 25.5V

NICAD ON CH1 IS 5.1V

This level is accessed by pressing both the "ENTER" and the "SELECT" keys simultaneously while in the Level 4 OPERATIONS display level.

The system will display the release level of its internal software at the top of this screen. This is important information, as it identifies to me exactly when this microcontroller was programmed. If the user experiences strange troubles, the first thing I will ask is what release level microcontroller is found at the top of the Level 2 screen.

The next line down is blank.

The third line shows the voltage being measured at the Dynamic line to the left of channel 1 input.

The 4^th line shows the voltage at the 9 volt battery. The Ultimate Charger II can have a rechargeable 9volt nicad battery connected to the 5 volt regulator powering the microcontroller for another layer of failsafe in case of power failure. I have found this level of failsafe to not be generally needed.

The 5^th line shows the voltage going to the 12 volt lead battery attached to the lead coming out of the hole to the right of channel 8. This voltage is adjustable by turning a small potentiometer inside the charger, just above the beeper.

The 6^th line shows the voltage at the charge bus. When the charger is running off the power line, it will show about 25 volts. When the charger is running off a 12 volt lead battery, the voltage can be set by turning the 2^nd small potentiometer inside the charger, just above the 12 volt adjusting potentiometer.

The 7^th line shows the current voltage at channel 1. Calibrating channel 1 will calibrate all 8 nicad channels.

Notice that when you first arrive at Level 3, the word "NICAD" is blinking. This means that currently "NICAD" Calibration is active. More about this later. If you press the "UP" key, the "NICAD" will stop blinking and "24V" will begin blinking, meaning "24V" calibration is active. If you would have pressed the "DOWN" key instead, the blink would have wrapped under to the top and the word "DYNAMIC" would blink.

If you do nothing during the period of 15 blinks, the microcontroller will assume that you are not interested in calibrating the function blinking, and will proceed to Level 4. You do not have to wait for 15 blinks, you can go to Level 4 at any time by pressing the "ENTER" key.

To actually run a calibration operation, I connect an accurate digital voltmeter to the function being calibrated, and use the "UP" or "DOWN" key to move the blink to the desired calibration, and press the "SELECT" key. Pressing "UP" or "DOWN" will increase or decrease a calibration constant which will be used on future readings. The calibration constants are stored in EEROM. If you should ever accidently arrive in calibration mode, press "ENTER" twice to leave immediately.

LEVEL 4 = OPERATION

DYNAMIC N-LD HISTORY

LEAD DYNAMIC TEST

NICAD DYNAMIC TEST

CHARGE-CYCLE-FLOAT

This level has 4 options. The main option is at the bottom, called "CHARGE - DISCHARGE - FLOAT". When you first arrive at Level 4, "Charge - Discharge - Float" will be blinking. If you press "ENTER", you will immediately go to Level 5. You can press the "UP" key or the "DOWN" key to proceed to another option.

The "NICAD DYNAMIC TEST" Option is used to test the dynamic response capabilities of a receiver nicad system. A special line is attached to an unused servo spot on the receiver bus and some violent maneuver such as a Snap Roll is executed (on the ground, of course). The Ultimate Charger II will capture a voltage sample every 2/1000th of a second. When it detects a sudden fall in voltage, it will capture another 80 voltage samples. Then 96 samples, 16 before the event, and 80 after will be display on the LCD.

This option is activated when blinking by pressing the "SELECT" key. The LCD will clear and display a 4 volt to 7.3 volt graphic grid for recording the 96 nicad receiver pack samples. Just the gridded display will remain until a capture event occurs. Then a graph of the voltage samples will appear on the grid, along with a value analysis to the right of the graph. The MAXIMUM voltage value in the 96 displayed samples, the MINIMUM voltage value, and the difference between the maximum and minimum value, called the DELTA value (the triangle is the Greek letter delta), will appear in the value analysis. The most important item in this display is the DELTA value, which is the instantaneous voltage drop over a 1/5th second period.

If the "SELECT" key (Think of it as the "SEND" key) is pressed at this point, the Ultimate Charger II sends a 9600 baud string of characters out to an attached PC. Once in the PC, the graph can be titled, saved, printed, or imported through the clipboard to some other program such as was done in this documentation. The "SELECT" key can be hit multiple times for multiple transmissions in case the initial graphic transmission was unsuccessful.

Hitting the "ENTER" key will rerun the NICAD DYNAMIC TEST. I typically rerun the test several times to get the best capture picture. The triggering system is looking for a .3 volt drop with characteristics of a servo starting to run. If the battery system is exceptionally good, you may have to try several times to get a trigger. This condition is very rare, however.

Hitting "ENTER" while waiting for a trigger will take you out of the test.

After a test has been run, hitting "SELECT" and "ENTER" simultaneously will take you out.

The "LEAD DYNAMIC TEST" option will clear the LCD and display an 8 volt to 14.6 volt graphic grid for recording the 96 12 volt Lead battery samples. Operation of this test is identical to the "NICAD DYNAMIC TEST" except that the input channel is now the "LEAD" battery leads to the right of CH8.

In this test, the triggering mechanism is typically the handheld motor used to start the R/C engine. Again, the test lasts just 1/5th of a second, so all you have to do is just touch the starter's switch.

The "DYNAMIC N-LD HISTORY" option currently shows 2 screens. The first shows the average nicad delta and the last 8 nicad dynamic delta values. The second screen shows the average lead delta and the last 8 lead dynamic delta values. Future software for the Ultimate Charger will greatly expand this history section.

Level 5 = Program

8 4.8V 1300MaH C

7 7.2V 1000MaH R

6 9.6V 500MaH C

5 6.0V 1600MaH Y

4 4.8V 300MaH C

3 4.8V 2200MaH C

2 6.0V 1100MaH Q

1 9.6V 800MaH C

This level provides the user with the capability of setting the Ultimate Charger II configuration to exactly how it should be handling his batteries. My other Ultimate Chargers used 8 or 10 position dipswitches to customize the charger. The Ultimate Charger II is so flexible that enough dipswitches could not housed inside the case! By use of just the 4 keyswitches, all the operations can be quickly programmed into the microcontroller. After the desired configuration is entered into the microcontroller, the EEROM is loaded with the custom configuration, so next time the configuration will default to the user's custom configuration.

Some chargers provide automatic selection of the battery voltage and current so that operation is much simpler for the user. But this bothers me. The full automatic charger would see no difference between a good 4 cell nicad pack and a 5 cell pack with a shorted cell. But I want a charger to make it clear to me in no uncertain terms if I have any problem with my R/C batteries!

The first column of numbers is the channel number. When you enter Level 4, the "1" in the bottom left corner should be blinking. This means that the change pointer is indicating channel 1 can be changed. Suppose that you are satisfied with the channel one setting, but would like to change channel 3. Press the "UP" key and wait for 2 beeps to occur. You should see the "3" blinking. If you miss and wind up at "4", no problem, just hit the "DOWN" key until you have the "3" blinking.

Now select a column to the right of the blinking "3". The 2^nd set of columns is the cell voltage. The Ultimate Charger II handles either 4 cell, 5 cell, 6 cell, or 8 cell nicad packs. These correspond to 4.8 volts, 6.0 volts, 7.2 volts, or 9.6 volts. To select this set of columns when the "3" is blinking, hit the "SELECT" key. The blinking words will now move right from the channel column to the voltage columns. Now the voltage should be blinking. Use the "UP" key to raise the voltage, and the "DOWN" key to lower the voltage.

When you are satisfied with which pack voltage size you have selected, then hit the "SELECT" key again to move another column set right. Now the milliampere hour rating of the pack will be blinking. Suppose your pack is a smaller pack. Press and hold the "DOWN" key until the desired pack size is blinking.

Pressing the "SELECT" key again will bring the blinking character to the last column, the mode. Notice that there are 8 single characters and their meaning in the "PROGRAM" block to the right of the switches.

PROGRAM

U = DQT

P = DRT

D = DCT

Y = CYCLE

Q = QUICK C

R = RAPID C

C = CHARGE

F = FLOAT

The real work of the Ultimate Charger II for each channel is set by selecting a single character from this list. The "UP" key will move the mode upwards in the list, with rollover to the bottom, and the "DOWN" key will move the mode downwards, with rollunder to the top. When the desired mode is blinking, then hitting the "SELECT" key will wraparound the blinking column back to the channel number. C for CHARGE and Y for CYCLE are obvious, but the other modes will be discussed later.

Once in the blinking channel column you can go "UP" or "DOWN" to reach another channel, or right with the "SELECT" to modify or correct another channel with "UP or "DOWN". What this system is achieving is the ability to make 97 different battery selections for each of 8 channels (776 possible battery combinations) times 8 different modes (6208 combinations) with just 3 keys.

Notice that we never hit the "ENTER" key. When you are finished programming the Ultimate Charger II and have verified that all is as desired, hit the "ENTER" key, and you will proceed to Level 6 to set the display. The Ultimate Charger II is counting the blinks. When any group of characters blinks over 15 times without any key activity, the charger assumes you are done, and will internally hit the "ENTER" key to proceed to Level 6.

LEVEL 6 = DISPLAY

SELECT DISPLAY SYSTEM

LOCK ONTO ONE CHANNEL

1 2 3 4 5 6 7 8

ALL CHANNELS-ROTATING

ALL CHANNELS AT ONCE

The original Ultimate Charger only had a 16 character alphanumeric LCD to display everything that was happening on the 8 channels while charging and cycling. The Ultimate Charger II has a graphic display with 128 horizontal dots by 64 vertical dots (8192 dots total), that can draw lines by illuminating adjacent dots or make characters out of dot combinations. The characters can be large or small, even miniature. Large characters provide easy reading, even at a distance. Small characters provide a considerable amount of information on a single screen. Miniature characters are used to label the grids on a graph. The Ultimate Charger II's alphanumeric character and line drawing software was designed so everything can function together in a single screen.

Level 6 gives the user the choice of 10 display systems. The bottom option, "ALL CHANNELS AT ONCE", will use the medium size character generating software to provide up to 21 characters on each of 8 rows. 21 characters on each of 8 rows gives the ability to show the channel number, the voltage, the current, the elapsed time and the function of all 8 channels simultaneously. You may have to stand close to the Ultimate Charger II and put on your glasses to read the display, but it will all be there at once!

Pressing the "UP" key selects the large character option, "ALL CHANNELS-ROTATING". This now uses a combination of large and medium sized characters to display a single channel for about 2 seconds before rotating on to the next channel. When channel 8 is reached after about 16 seconds, channel 1 will be redisplayed. In this system, each channel is displayed about 4 times a minute. "Just be patient, your channel is coming." But you can see the statistics on your channel at a short distance without your glasses.

Pressing the "UP" key some more will select one of the numbers "1" to"8". In this display mode only the selected channel is ever displayed. This is quite handy when you are cycling or experimenting with the battery on just one channel, and don't care what is happening on the other channels. If you should overshoot your mark, press the "DOWN" key to back up, and of course, you can wraparound to get the right display system blinking.

When you have indicated which display system is to be used in Level 7, hit the "ENTER" key. If the charger gets no input from you while blinking on a display system, it assumes that you want that display system and hits "ENTER" for you and proceeds to Level 7.

Important to remember is that this only affects what is happening on the LCD screen. The charging, cycling, etc will be happening identically the same regardless of what the LCD shows.

LEVEL 7 = RUN

This time the display will be different, depending on which of the 10 display options you selected in Level 6. Let us assume that you have good eyesight and selected the "ALL CHANNELS AT ONCE" option. The LCD might appear as:

8 5.7V 1280Ma 415H T

7 7.4V 900Ma 10H R

6 10.3V ?Ma 1H C

5 5.9V 1400Ma 300' D

4 OPEN CYC 30 WKS AGO

3 5.8V ?Ma 14H C

2 6.9V 1080Ma 4H Q

1 11.3V 810Ma 13H C

The Ultimate Charger II is really working at this level. All 8 channels are at different levels, and the internal microcontroller is keeping track of every channels present status and important aspects of its battery's past history if known. 40 times a second the charging and discharging pulses are updated. The microcontroller also is logging the voltage of each channel, so that if it senses that something is radically changing on any channel, like being unplugged, the beeper is called upon to give an audible analysis of the battery's health, for instance.

The box under the keyswitches shows the 8 modes during the Level 7 = RUN operations.

RUN

C = CHARGE D = DISCHARGE

R = RAPID E = RECHARGE

Q = QUICK I = TRICKLE

T = TRICKLE F = FLOAT

One of these 8 characters will appear in the last column in the "ALL CHANNELS AT ONCE" display mode. In the large character modes the character will appear in the center of the LCD. The function and mode idea may be a bit difficult to understand. When considering what operation is to occur, like "charging" or "cycling", I refer to this as a function. When actually performing this function in Level 7 = RUN, charging has different aspects that I refer to as modes. A part of charging is "OPEN" when a battery is not connected, "CHARGING" when first connected, and "TRICKLING" when the battery has been fully charged and has its charge current level reduced to keep the battery topped off, ready to go now, tomorrow, or next month.

Cycling is rather complex, as it can be "OPEN", on "DISCHARGE", "RECHARGING", or on TRICKLE waiting to DISCHARGE.

I try to use the first letter of the mode, but if already in use, I used the 2^nd letter.

The display is rather obvious, but has some fine points. The voltage displayed in the 2^nd column set is the actual voltage of the battery at this point, not its nominal voltage written on the side of the battery pack. The 3^rd column set is the mah rating of the pack determined by the last time the battery was cycled, again, not the value printed on the side of the pack. If you have not cycled this pack, a "?" will appear to let you know that the charger can't really tell you how good this battery is until you do a cycle operation on this channel. Your receiver and servos can't read the side of the pack; they operate on these voltage and mah values. If you change the voltage or mah settings of any channel in Level 5 = PROGRAM the Ultimate Charger II assumes that you are using a different battery and clears out the old mah ratings derived for the previous battery on this channel. The cleared value results in the "?" being displayed.

The 4^th column set is the elapsed time in the displayed mode. Most of these times will be less than 16 hours, but a battery could be left on TRICKLE for a considerable length of time. 9999 hours is 416 days or about 13 ½ months. This is real auction material when an airplane shows this much time on TRICKLE!

When a battery is in DISCHARGE mode, the display is slightly different. The MAH columns are showing the accumulated MAH rating of this battery, and the time column is reading off the number of minutes in DISCHARGE mode.

When a battery is removed from a channel (to do crazy things like fly, for instance) "OPEN" is displayed. I also show how long it has been since this channel was cycled. This time period is only valid if the Ultimate Charger II is never allowed to go back to Level 0 = OFF. Some people cycled their nicads frequently, some seldomly cycle. I cycle my batteries about every ½ year, so I guess I fall in the "seldomly" category. But every time you use a nicad pack and OPEN the circuit, the Ultimate Charger II will let you know the score. Each channel's calendar will be reset when you cycle the pack on that channel.

All of this sounds complex, but you only have to enter something if you want to change how the Ultimate Charger II operates. If satisfied, you can let the charger go from Level 0 = OFF to Level 6 = RUN all by itself. If computers are a baffling mystery, a friend can do the keyswitches for you. All you have to do just unplug the packs to fly and plug them back in to charge. Everything else is automatic.

You may get the idea that the Ultimate Charger II is complex. Well, I have spent 2 years designing and programming it, and I work fast. It is a great unit though, and I hope you enjoy it as much as previous Ultimate Chargers are treasured.

Using the Ultimate Charger II

Plug in the Ultimate Charger II. The Charger will identify itself with a beep and a message "ULTIMATE CHARGER II" in large letters.

Then the 4 functions and the channel and display settings will be shown. If the settings are incorrect, use the UP, DOWN, or SELECT key to change the settings.

Assuming that nothing is connected yet, every channel should read # OPEN CYC ? WKS AGO Plug in a battery pack to any channel. The Ultimate Charger should make a single long beep. When the display finally shows this channel again, the display will show # XX.XV 0Ma 0H C , (where XX.X is the battery voltage read). 0Ma indicates that this battery's capacity is unknown until cycled, 0H shows the elapsed time, and C indicates that the Ultimate Charger II is now Charging the battery. The elapsed hours on Charge are displayed for 16 hours. Then the display will change to # XX.Xv 0Ma 0H T, meaning that the charge has been reduced to a Trickle charge. The elapsed time on Trickle is now displayed, showing from 0-9999 hrs (about 14 months). If you disconnect the battery pack at any time, you will get a voltage analysis in beeps. The charging current is restored and the timer is reset. # OPEN CYC ? WKS AGO will be displayed. Reconnect the battery and the charging process starts over again.

Normal operation goes like this: Plug in your airplanes or boats, and your transmitters.

If you plug in the battery and no sound results, either you reversed the wiring polarity, or you left the receiver or transmitter switch in the "ON" position.

When you are ready to fly or float, check the channel display. Unplug the battery. The Ultimate Charger II will check its memory for the most recent state of the battery before it was unplugged.

Listen to the beep analysis, to make sure that the battery pack that you want to use is fully charged or high, not weak or shorted.

If the battery was on Trickle charge, and was fully charged, the charger will make a single short beep.

If the battery was on Trickle or Full charge, and the voltage was a bit low, indicating a partial charge, the charger will make a short beep and 2 long beeps (W for WEAK in telegraph code) - The pack is <1.35v/cell. Be very cautious with a battery pack diagnosed as "weak". The pack may be partially charged, need cycling badly, or just tired and ready for replacement.

If the battery was on Trickle or Full charge, and had a shorted cell, the charger will make 5 sets of 3 short beeps (S for SHORT in telegraph code) - The pack is <1.1v / cell. Make sure that the battery pack that you want to use is not shorted (15 short beeps). Your airplane radio will either not run at all, or will crash about half way through the first flight.

Sometimes the charger will make 4 short beeps when a channel is unplugged. The is an H for HIGH in telegraph code. This occurs when the battery voltage is unusually high (>1.5v/cell), probably OK, but keep your eye on this pack, because old pack and packs with high internal resistance will read high, but typically won't pass the dynamic nicad test.

Have fun. When you return, plug them back in. They will be ready to use again tomorrow, or next month, or next year.

Not only is this system carefree, it also gives an indication, by reading the Trickle hours, of how long it has been since each unit was used.

You may want to cycle your pack. In this case, reprogram the channel to cycle (Y). The channel will Discharge, reading the accumulated MAH and time in minutes as it discharges, and Recharge for 16 hours, Discharge, reading the accumulated Mah and time in minutes asa it discharges, and Recharge for 16 hours,..... until this channel is taken off Cycle. The first Mah rating may not be calibrated, as the Discharge could occur before the pack was fully charged. Subsequent cycles should be calibrated. The readings will be logged so that weak packs can be replaced before they cause problems. The discharge rate is set at 150 ma for small packs and 300 ma for the 1200 to 3000 Mah packs. The Discharge continues until the shutoff voltage or 8.7 volts, 7.6 volts, 5.4 volts, or 4.3 volts is reached for 8, 6, 5, or 4 cells packs respectively.

When finished cycling a few days later after 3 or 4 cycles (Discharge & Recharge = 1 cycle), averaging about a cycle a day), reprogram the channel from "Y" (Cycle) to "C" (Charge-Trickle) to resume normal operation. The pack will be charged and ready the next day, or sooner, depending on where the battery was in the Recharge portion of the cycle.

The white area on the face of the case above each channel is provided so that you can write the name of the transmitter, airplane, boat, pilot, etc. assigned to this channel with a water based transparency pen such as Vis a Vis by Sanford. Wipe off with a damp cloth, then 409 spray cleaner and wipe off quickly, to change labels.

Force Trickle

Suppose you went to the field to fly your fully charged airplane, but it was raining. You didn't even take your airplane out of the car. When you got back home, and put the airplane on the Ultimate Charger II, the charger will try to charge the battery for 16 hours. It is already fully charged; you want it to keep it charged by continuing the Trickle charge that it was on before you left.

The Ultimate Charger II has a feature just for you. It is called Force-Trickle. A channel can be put into Trickle mode by a simple sequence of plugging, unplugging and plugging.

Connect the charging plug from the Ultimate Charger II to the airplane (or transmitter). You should get a single long beep.

Within 20 seconds, unplug and replug the airplane (or transmitter. You can also turn the receiver or transmitter switch ON for a second and then back OFF. A single short beep verifies that this channel has been forced immediately into Trickle Charge mode.

If you did not get the verifying short beep, unplug the airplane (or transmitter), and try again.

If you are using paralleled channels for higher current capacity, you will get a second long beep after the short beep. Unplugging and replugging again will Force Trickle the second channel. If you don't do the second unplug and replug, you will have the first channel on Trickle and the second on Full Charge, resulting in an effective current somewhere between Trickle Charge and full Charge, not what you had in mind.

Cycling Your Batteries

The discharge current of the Ultimate Charger is set to 150 ma for packs that are 300 mah to 1100 mah in rating. Packs that are 1200 to 3000 mah in size are discharged at 300 ma. This results in a longer cycle time than competitive cycle chargers, but the mah rating will be closer to the factory rating which uses a C/5 discharge rate to determine the mah rating. Discharging a 500 mah pack will take about 3 hours, a 1200 mah pack will take about 4 hours, and a 3000 mah pack will take 10 hours.

The discharging function is performed on a single channel at a time to limit the thermal loading on the charger, as well as not stressing the Discharging IC. However, a number or even all channels could be cycling or on DCT, DRT, or DQT. When more than 1 battery pack is being cycled, a queue is formed for the discharge function.

Discharging is the smaller component of cycling; most of the time is spent on Recharging. Suppose you wanted to cycle 3 channels. Ch1 has a transmitter with a 600 Mah pack, Ch2 has an airplane with a 750 Mah pack, and Ch3 has another airplane with an 1800 Mah pack. You program all 3 channels to "Y" (Cycle) and go away for a couple of days.

Ch1 will get the Discharge "pin" and will take about 4 hours to discharge. Then Ch 1 gets recharged and Ch2 gets the discharge "pin", taking about 5 hours to discharge. Finally after waiting for 9 hours, Ch3 gets the discharge "pin" and discharges for about 6 hours. After about 15 hours, all 3 channels have been discharged. But now every channel to be cycled has been time staggered, so when the next round of discharges are due, each channel gets the discharge "pin" when they want it. So the result is a charger that lasts forever, and, since Cycling is infrequent, minimal inconvenience occurs.

DCT, DRT, and DQT

DCT, DRT, and DQT can be thought of as Single Cycle operations. For those really worried about "memory" buildup (better called "Voltage Depression"), DCT is a neat way to avoid "memory".

DCT will Discharge, Charge, and then Trickle the nicad pack a single time whenever the pack is plugged into the charger. Cycling will continuously Discharge and Charge. With Cycling, you may come back a few days later to a discharged pack, not ready to fly. DCT would be done, and the airplane ready to fly. DCT will take longer to accomplish than the standard Charge-Trickle operation, because of the time that the additional Discharge function takes. But when finished with Discharging and Charging, and on Trickle, the battery is really topped off and ready to fly.

I use the DCT function to determine the number of flights safety margin. Say, I normally make 4 flights on an airplane when I go to the field. How close to the end of battery charge am I? What I do is program this channel to "D" (DCT) and plug in the airplane after flying my 4 flights. The Ultimate Charger II will Discharge the pack before Recharging. The Mah rating displayed is the remaining capacity after flying. I divide this remaining capacity by the full capacity of the pack. I make sure that I have at least 25% remaining capacity safety margin after flying!

Example: I use 5 cell 1600 Mah packs in many of my larger airplanes. I make sure that I have at least 400 Mah left as shown on the DCT test, or I had better either take fewer flights or get a bigger pack. However I have found that I can safely fly 6 flights on some planes because the packs came home with ½ their capacity remaining. This was critical knowledge because a recent IMAC contests had 6 flights in a single day.

DCT, DRT, and DQT are identical except for the recharge rate & time. I rarely use DRT or DQT because I like to be nice to my batteries with slow charging, but someday I might need to use DRT or DQT.

Float

Float is something that I added to the Ultimate Charger II after noticing that batteries that short out also are batteries that rapidly self-discharge due to internal insulation breakdown. A good nicad battery will hold its charge for about a month or more. A battery pack that is pr9ne to shorting will lose its charge in a couple of days. Float will not Charge or Discharge your battery, but will just monitor & display the voltage. If you are not going to be using a pack for a while, fully charge it and then put that channel on Float. Monitor the voltage on this pack every day or so. If it can't hold the charge to >1.2 volts/cell for a week or two, consider it ready for placement in you nicad graveyard. This will save your plane!

Very Large Nicad Batteries

You can charge battery packs larger than 3000 Mah by making a Y connector that connects 2 or more channels in parallel. To Cycle, disconnect to 1 channel, otherwise you will have one channel discharging and the other(s) charging, and never get anywhere.

Single Cell Nicads

You can charge a single cell nicad (1.2 v nominal) with the Ultimate Charger II. I calibrated the original Ultimate Charger's software for a single cell, but because the per channel costs are higher, did not do this on this version. I charge 1500 Mah Nistarters with the charger, and I have a single 4400 Mah battery in one airplane for a constant on board glow for a MOKI twin cylinder engine. I program the channel as a 4.8v pack, and then with a milliammeter in series, adjust the mah rating to C/10. Each time the nicad is disconnected, a "shorted" set of 15 beeps will occur, because the voltage was too low, but it will really be OK.

Lead Batteries

Lead batteries come in several forms and names. The Wet Cell is commonly used in automobiles and motorcycles. Motorcycle batteries with larger capacity are nice for starting larger planes with high current starters. Most field boxes use the sealed lead batteries, which may be either a solid electrolyte or a gelled electrolyte. Any of these 3 can be charged and used by the Ultimate Charger II as long as the ratings are under about 15 amps. The charging circuitry will be strained if a larger discharged battery is used. I a larger fully charged battery is connected, there should be no problem.

The Ultimate Charger II's lead battery charging system has 2 levels: Charge and Float. One channel of the Microcontroller's A/D converter monitors the lead battery voltage while in Level 7, the normal RUN level. If the battery voltage is <13 volts, the lead battery charging circuit puts out >14.5 volts @ 1 amp to the battery. When the battery voltage reaches 14.5 volts, the charging circuit is cut back to 13.5 volts, the float level. Most batteries will then float, at about 13.3 volts, ready for use.

Occasionally I use the Dynamic Lead test to graph out how the lead battery is performing. All I have to do is press my starter button when in the Dynamic Lead test. The Lead Battery voltage delta should be between 2 and 3 volts. Less than 2 volts delta means your starter, switch, or wires are going sour, and greater than 3 volts means you lead battery is going. Fully charged, but less than 13 volts max means you have a shorted cell in the lead battery Spikes on the graph indicate a bad starter switch or bad brushes. It's great to have a dependable starter now!

Connecting the Ultimate Charger II to a PC

I wondered just how useful this would be, as most airplanes are kept in the garage, and the computer is in the house. But ½ of the preliminary orders want the PC software & cable option. I have gotten some amazing graphs over the last couple months of developing the Ultimate Charger II. The software was intended for use with a small LCD storage oscilloscope, but worked beautifully by making the Ultimate Charger II send out the same codes as the oscilloscope. It saved me 6 months of time developing my own software.

The software is loaded into Windows 95 and the opto-isolated cable is plugged into a free COM port. My laptop computer is handy, because I can take it out to the garage to get the data, then bring the laptop inside where I can save & print the graph for my records, or import it into other software. I sometimes make it into a *.JPG file that I can send out over the Internet. By putting it into the clipboard from the capture program, I pasted typical waveforms into this WordPerfect document.

Future software for the Ultimate Charger will greatly increase the graphing capabilities of the Ultimate Charger II.

If at a later date you wish to add this download to PC capability, you can get the cable & software P/N # 9103449 from Tech America (a high tech Radio Shack offshoot) (800) 877-0072 for about $20.

Considerations

Since this is a computerized device, several unique actions can happen. Most computers step through a carefully designed set of instructions called a program. If anything unexpectedly disturbs this flow, the computer may become confused. The most frequent disturbance is a power line glitch caused by a lightening strike or power company problem. Another cause can be a very strong RF field or electrostatic discharge. The Ultimate Charger II is designed to be insensitive to these problems, but should this happen, the computer must be reset so that it finds itself. The Ultimate Charger does not have an external reset switch, so just momentarily unplug the charger if you see the LCD staying static with strange characters on the LCD. The failsafe battery system usually solves power failure problems.

Never remove all power (wall transformer and Lead battery) from the Ultimate Charger II while nicad packs are still plugged into the charger. First remove the nicad packs, then remove power.

Some customers indicated that the Ultimate Charger was going to be mounted in a trailer with their airplanes. Remember that the charging stops when the electricity stops. Plugging the charger into the cigarette lighter is simple, but most vehicles remove 12 volts from the cigarette lighter when the ignition key is completely turn off. Avoid the problem by supplying power to the Ultimate Charger from a dedicated deep cycle 12 volt battery. Connect this battery to the car's charging system through a high current diode (Cathode or bar end towards the battery) so that this battery is charged but not discharged by the car.

The Ultimate Charger II is built very ruggedly, but if you put it in a trailer, driven over some field's dirt roads, shock mount the charger in thick, soft, foam rubber to make sure it will be functioning perfectly at the contest.

Some transmitters (such as Futaba) have a forward biased diode between the charging jack and their 9.6 volt battery. This results in an inability to externally discharge the pack. The Ultimate Charger II determines whether a channel is connected by monitoring the voltage coming from the pack. With a diode in the line, that charger will not see any voltage, and will report the channel open, even though connected. Three options exist. 1. Don't connect this transmitter to the charger. 2. Disconnect the battery internally and Cycle it directly. 3. Bridge a shorting wire made from a single strand of the multi-strand wire used in servo leads across the diode. Unless you know what you are doing, find someone to help you with #3. This diode will also interfere with charging. If so, find someone to help you with #3. If you have the Internet, there is a description & pictures on bypassing the diode in Futaba transmitters at http://www.geocities.com/CapeCanaveral/Hangar/1071/8uaps.htm

Some people are concerned about voltage drops in long charging cords. Relax. If you use the suggested speaker wire for extensions, you will have no problem. The battery is measured at charging and discharging pulse off time, so the voltage measured at the charger would still be accurate if 500' of thin wire were to be used.

TV Interference is always possible from all digital type circuits. The Ultimate Charger is designed for no RF problems either from it or to it. The case is metal, all leads are bypassed, and the microcontroller runs at a low clock frequency. I live in a TV fringe area, and there is no interference coming from the Ultimate Charger II. Should you experience TVI, reorient the charger leads or TV antenna.

Some people may want to watch the current pulses going to the battery. I don't know why, but if so, expect about 150 ma or 300 ma on Discharge, battery mah rating/10 ma on Charge, and battery mah rating/40 on Trickle, all average pulse currents. Meter polarity will be reversed when Discharging. A 200 ma to 300 ma each side of center DC meter is ideal. Your little pocket VOM will work too, but a DPDT polarity reversing switch will be needed.

Backlit Display

Some Ultimate Charger II's were built which have a more expensive LED backlit display. This display is illuminated by plugging a second transformer into an RCA pin jack on the rear side of the charger. This transformer will provide about 4 volts @ 100 ma to the LCD's backlit circuitry. If the AC line power should fail, the illumination goes out, but the charger's field box battery should keep the charging going even if the display is less visible.

Failsafe or Field Charger Operation

Like most digital clocks and computers, if the power goes off at your house, the system stops. The Ultimate Charger II has two fail safe systems which consist of your 12 volt lead fieldbox battery or an internal 9 volt battery. As long as the power lines are hot, the 12 volt lead battery is charged or float charged, as well as powering the rest of the charger circuitry. However, when power fails, the 12 volts from the lead battery will provide power for several hours until the power lines are restored. The lead batteries tried were rated at between 7 AMPS to 14 AMPS . The resultant system will keep charging 2 channels for about 10 hours or more. Sometimes the fieldbox battery will not be connected, though. You might be using it to start your engine at the field when power fails at home. If you want non-stop charging, connect a second 12 Volt battery each time you take the fieldbox battery away in case of power failure while you are at the field.

To add the 9 volt battery, take the cover off the charger, remove the 4 3/8" 6-32 screws that hold the charger to the red bottom pan, and after taking the charger out of the case, loosen the four 4-40 nuts that hold the LCD PCB to the main charger PCB. Notice the 9 volt battery location sandwiched between the LCD board and the main circuit board. Use a polarized 9 volt battery connector connecting the red lead to the + 9v pad and the black lead to the - 9v pad.

I think that you are better off with a 2^nd 12v lead battery, though, which will provide continuous charging, not just keep the values alive.

Troubleshooting

Display Blank - Check power. Remove, power, all batteries, wait ½ minutes & plug back in.

LCD shows weird characters - You electrostatically zapped Charger. It should self reset.

Display not scanning - Normal, you programmed to scan a single channel. Otherwise, Reset.

Display hard to read - Adjust the contrast control under the LCD. 1/16 turn will usually correct.

Battery voltage off on all channels. - Normal if within a tenth of a volt or so. Also caused by one battery connected backwards - careful - that could blow the microcomputer IC.

Battery voltage off on one channel. - Bad battery pack. Transmitter diode problem. Connector problem including reversed plug to JR receiver charging jack will read the remote control cord voltage (that one got me!). Resistor divider problem.

One channel shows OPEN though apparently connected. - Airplane (boat) or transmitter on/off switch left on or is broken. Charging connector not seated or reversed. Broken lead. Reversed polarity ( Oh No!)

Repairs are no longer available

Dr. Robert Suding SAI

27107 Richmond Hill Rd.

Conifer, Colo. 80433

(303) 838-6346

CALIBRATION SETTINGS FOR THIS CHARGER

DYNAMIC = _____

9V BATTERY = _____

12V LEAD = _____

24V CHG BUS = _____

NICAD = _____