Please Help!! 9Z battery won't hold charge for more than 2 days.

[ericb]

I need help bad!!!!! My 9Z battery will not hold a charge for more than 2 days. This is with the battery out of the TX. I have switched batteries and it does the same thing. I have tried bypassing the resistor on the battery board and it does the same thing. I need to charge every time I go to fly. I now have a 2500 mAh Nimh in it. HELP!!!

[dmcquinn]

when you say your battery will not hold a charge, what exactly is the symptom? What is the voltage under no load? Under 300 mA load? Have you discharged it under a known load and measured its capacity?

[MrKiwi]

What are you using to charge it? It may not be getting fully charged and show premature voltage leval..

[klhoard]

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Will the individual cells hold a charge when you take them out of the battery case?
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Perhaps something is shorted in the circuitry of the battery holder. I had Radio South bypass all of that stuff in mine so I can peak charge the cells.
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[ericb]

I have bypassed all of the circuitry in the battery case. I have a connector soldered right to the leads on the pack. I have used a peak charger and an Accucycle Elite to charge them. What I mean by not holding a charge is after I have a full charge on it, I will come out after a couple of days and my radio will be either completely dead, or the low battery alarm will be sounding and it will either show about 8 volts, or die within a couple of seconds. When I am done charging it, it will show around 11 volts on the screen.

[torquen]

Sounds like when you tried bypassing the circuits you messed something up. If its not the batter then just get a new case from tower hobbies. Tower also sells a chip you can plug into your battery case that will bypass the diode so you can quick charge with a charger that cycles.
Garrett

[ericb]

It was doing it before I did anything to the case. My mods to the case were an attempt to aleviate the problem.

[BuzzBoy]

You could try: Remove the battery from the cassette. With the battery pack removed wire a connector directly to the battery and cycle the pack down. Recharge on a C10 for 16 hrs or so. Do another cycle down and see if the pack performs as it should. If not, re-cycle and see if the pack come back around. This will tell you if your cassette is buggered up of if in deed the pack is bad.. Buzz

[Dangerous Dan]

call radio south and order an new battery cartrage circuit board they are less than 10. have them do the mod so you can charge direct with a peak charger.

[Dangerous Dan]

Also if these are NIMH you need to charge at approx 1/2 C with a wall wart the first 5 or 6 times before using a peak cahrger.

[Zeeb]

	Quote: Originally Posted by torquen
	Sounds like when you tried bypassing the circuits you messed something up. If its not the batter then just get a new case from tower hobbies. Tower also sells a chip you can plug into your battery case that will bypass the diode so you can quick charge with a charger that cycles. Garrett

If you're referring to what is known as a "Polyswitch" that does not work on the 9Z, the small board inside the battery case must be modified to allow installed battery cycling.

As to the problem at hand, if you've had it do this with multiple batteries, it sounds like you've got a current draw while the tx is shut off. Do you have an amp/watt meter you could setup to check for a current draw while the tx is turned off?

[torquen]

[quote=Zeeb;280484]If you're referring to what is known as a "Polyswitch" that does not work on the 9Z, the small board inside the battery case must be modified to allow installed battery cycling.quote]

Zee, not sure what its called but its a little plug that you install into the battery case. The plug has a series of pins and bypasses the diode so you can cycle or use a pulse charger. I have had it for about 8 years and it does work LOL.

Simple solution to this matter is to get another case or circuit board if you have already changed batteries. Not worth the risk at all of a battery dieing in flight.