Practically new TP battery dead

[curtie44]

I have a TP 2200mAh extreme series battery that died last weekend. I didn't discover it until yesterday when I tried to charge it up for a flight. This battery probably has less than 15 flights on it and has always been charged with a TP1010 charger and a TP205V balancer. I also have the count down timer alarm on the DX7 set for 7:30. Additionally I have the LiPo cutoff voltage on the Align speed control set for "Lipo high voltage protection" which =9.6V for the 3 cell TP pack. When I put the pack on the charger I get a "Voltage error/wrong polarity error". The balancer blinks an error as well. So my question is, how could this happen? The flight that damaged the pack went normally without any signs of battery failure or over-discharge. When I put my meter on the balance leads I get: White=2.83V Blue= 5.58V Orange=8.36V So each cell is 2.83, 2.75, 2.78 respectively. I called TP and explained my situation and the CSR told me to send them the pack for evaluation. My guess is I am going to be out the $85 for the pack that TP will say I over discharged and subsequently damaged. But with all the protection steps(ESC cutoff, timer, balancer), again, how could this happen? I have another TP pack (2070 mAh) that has gone through approximately 1/3 more charge cycles that is still kicking. I just want to make sure it isn't something I'm doing wrong. I am a bit of a noob...i've only been flying electric heli's since Dec.

Oh yeah...by the way...my set-up is
T-rex 450SE
Spektrum DX7
HS-65HB on cyclic and Futaba S9650 on the tail
GY-401
stock Align ESC and Motor
TP1010 charger and TP205V balancer
1 TP2070 mAh extreme series and 1 dead 2200 mAh extreme series LiPo :(

[creightoncarr]

What pinion are you running on the motor? What's your pitch range? What kind of flying are you doing? I know many people get those kind of flight times just hovering around and doing some basic FF with slow headspeeds. I only get 5:30 max out of my TP extreme packs (2200's) running the head at about 3150 rpm. If I fly any more than that my packs would be like yours.

FWIW, you can probably salvage that pack and it will continue to perform just fine for many, many more cycles. With the 1010/205 combination it should allow you to do this. Have you upgraded the firmware to ver 2.1a? If so, when you connect your pack and it detects the voltage, it will give you the option to press "INC" to restore, or save the pack, or something like that. It will only trickle charge for a minute at a time before you have to press "INC" again. You may have to sit there and press it over and over again, but eventually it will bring it back up to the proper level and begin the normal charge process. If you haven't upgraded the firmware, the usb interface cable is only $20 and you can probably pick it up at your LHS. I think it's a better option than waiting on TP to "evaluate" your pack.

Worst case scenario, if you have a charger other than the 1010 that will charge batteries of other chemistries, you can charge as a NiCD at a very small current for a minute or two to bring the pack voltage back up to a level where the 1010 will charge it properly. This should be a last resort, and you should monitor the pack closely if you do this. I did this on a couple occasions in the past before the 1010 with no problems.

[joehelicopter]

check to see if one of the balancer wires may have come loose from the pack.I have that problem with all my Eflite packs-solder joints can become brittle and break away from the Tab....

[DebianDog]

7:30 seems like an AWFUL long time depending on the headspeed.

[curtie44]

Thanks to all of you for your input. To answer some of the questions posed...

I am running the stock 11T pinion. My pitch range in normal mode is -2 to +9. In stunt 1 -11 to +11. I have no idea what the head speed is. My throttle curves are: Normal mode, 0,50,80,95,100% Stunt 1: 100,95,90,95,100. Up until last weekend when the pack crapped out, all I did was basic FF and hovering. Last weekend was my FIRST flip and roll and VERY brief inverted hover (woohoo!) I have always been able to get 7:30+ out of both the 2070 and the 2200mAh TP LiPo's. I guess I mistakenly thought I would always get that kind of flight time out of them regardless of the type of flying I was doing. But really all I did was 2 or 3 little rolls and maybe 2 flips. My knees were shaking too much after that to try anything else. I guess I should cut back the timer on the dx7 so I don't mess up my other pack. I just thought that the ESC LiPo cutoff would have clued me in before this happened, or I would have noticed a decrease in power. Hey Creightoncarr, when you say you get 5:30 max out of your packs, that's pushing the bird pretty hard, right? FFF, 3D, etc...

I think I will go ahead and order the USB cable and try to save the pack.

Joe, I believe the balance leads are still intact because otherwise I wouldn't be able to read voltage on the balance connector (I wiggled them with the meter on it to see if I saw the voltage jump around).

It really surprises me that 7:30 seem so long to everyone....again because I don't know any better. Remember, all I have done up until last weekend was basic FF and a lot of hovering. Very littl flying in stunt mode. Oh well....we'll see what happens with the 1010 firmware upgrade.

Thanks again Freaks!

[creightoncarr]

Five and a half minutes is with a lot of tame 3D, I don't do a lot of stick banging (at lease not intentionally). I could probably get about 6:15-6:30 out of the packs if I were doing just FF or dropped down to the 11T pinion. The low voltage cutoff on the ESC is you very last line of defense. Even at the high protection setting, if it kicks on you've gone too far. Your best bet is to invest in a Lipo alarm and use the timer religiously. I don't have a Lipo alarm yet, but I keep meaning to get one. The timer works fine as long as you know what you can get out of the packs and you remember to start it each time. That's my problem is forgetting to start it. I wish JR would include a timer on throttle feature in their radios like Futaba does. I read somewhere that even the new 12X won't have this option. It seems ridiculous not to since electrics have gain so much popularity.

Anyway, if I were you, I would set my timer for five minutes and run a couple of packs with your most agressive flying. Then monitor how much you are putting back into each pack and figure out what you can get for each flight to avoid overdischarging. Even if you don't fly that "agressive" style each flight, it's better to underdischarge than overdischarge.

[curtie44]

When you charge your packs, do you do a full charge or charge to 95%?

[curtie44]

Ok I just ordered the TP USB programming cable and a new TP2200 mAh LiPo. Hopefully I will be able to save the other LiPo and if not, maybe TP will repair it for a reasonable cost.

So who makes a good LiPo alarm?

[creightoncarr]

I hear Efliernz's lipo alarms are great. Check out this thread --> http://www.helifreak.com/viewtopic.php?t=36680&highlight=lipo+alarm

[Skiddz]

I 2nd Pete's (Efliernz) alarms. Got one on my 600 and my "old" 450SE. Gotta PM him and get another for my 450SEV2.. He built me some "custom" units without the buzzer and they're more than bright enough for use in the bright sun.

[curtie44]

The USB programmer arrived today and I am currently in the process of trying to save the pack. So far so good......It has been going for about 15 minutes now and is up to 11.2V. That INC button sure is getting a workout!

[curtie44]

well...it charged. I guess time will tell if the pack got damaged. I'm gonna go fly now.

[joco]

BTW... I had the same problem a week back... Called TP and they said to send it back. I wonder if there is something going on with some TP2200 packs.....

[curtie44]

Did you sent it in? If you did/do, I would be curious to know if they replace it or just "save" the pack and return the same one to you. Mine was ok after about 20 minutes of the "save" charge. After that the voltage was high enough to allow it to charge normally, taking in about 1800 mAh.