Bad battery?

Welcome to RCTalk

Come join other RC enthusiasts! You'll be able to discuss, share and private message with other members of our community.

This site may earn a commission from merchant affiliate
links, including eBay, Amazon, and others.

wacmartin

DAMN TREES
Messages
1,228
Reaction score
85
Location
Ontario Canada
RC Driving Style
  1. Bashing
Okay guys need some help. So I've got back to running just the Savage Flux after taking some time off from RC. One of my batteries is giving me trouble now, it just seems to be 1 cell in a 2s LiPo. In balance charge mode it says it's at 4.20 this is what I assume to be my problem cell, and the other cell was at 3.80 and doesn't seem to be catching up. Now I tried a discharge and it won't happen because the problem cell says it's at 1.72 and the good cell is at 3.55. Then in fast charge mode, storage mode, and just regular charge mode it says the problem cell is at 4.05 and the good cell at 3.70, and the charge only lasts 10 seconds because they both jump to 4.20 real quick. My charger would also tell me if a cell is at to low of a voltage to charge.

I just storage charged them about a month ago, they always stay at a storage charge, they've always been balanced charged, always stored inside. It's not the charger ( well I hope not) because just charged and balanced and storage charged 5 other batteries with no problems, including the identical battery.

Could it be the balance plug? I'm not comfortable with changing that out at all. Should I just discard the battery?
 
Sounds like an anomaly too me.
I’d avoid the frustration and get rid of it. ✌?
 
Well I was able to equal out the cells to 4.20 each, went to storage charge bad cell says 3.72 and drops to 3.50 after 15 seconds and the charge shuts off.

this is anomaly to me as well, the battery is going an a ammo box and out to the garage for the night.
 
@wacmartin the voltage of a LiPo cell can be read like so:

4.20v = 100%
4.03v = 76%
3.86v = 52%
3.83v = 42%
3.79v = 30%
3.70v = 11%
3.60v = 0%

So the "bad" cell you have is reading 100% charged while the other is only about 50% charged. But when you discharge you are WELL below the recommended voltage.

If it was me, I wouldn't waste any time on the battery and would replace it instead.
 
I'm not wasting my hydro on this thing anymore. It was just really strange to me that the voltage reading were so far off in different charge modes. As soon as it would come off the discharge or storage charge and I put it on to balance the voltage was right back up there where it should be. So I don't think it was actually discharging at all, but I don't think it was charging either.
as farther evidence the battery is toast, my wife came into the hobby room yesterday and asked why it smelled so sweet in here. That's when I knew it was done, I guess I couldn't smell it because I smoke, woman also have stronger sense of smell then as well.
 
Try charging the dropped cell on its own using your charger, through the lipos balance tap, I've recovered a few batts like that

 
I had one of my SMC 9000mah 2S packs go from working fine to dropping voltage from one week to the next. It had quite a few cycles on it and was over a year old. One of the cells in it wouldn't hold a charge and would self discharge overnight from full to less than 2V. I tried cheating and using my old NiMH charger to charge the one cell up to 4.1V, then put it on my lipo charger to balance it. Then I let it sit overnight and the once cell dropped to 1.7V on it's own.

I drained the pack completely to 0 with a couple brake lights, then cut the main leads and twisted them together to keep it from recovering. Decided it wasn't worth the risk of trying to charge it or mess with it anymore. A 9000mah pack is a lot of lipo for a fire.

The pack was working "fine", but it and it's sister pack (I always ran them in pairs) had been taking 50% longer to balance charge for the last 3 months or so of use.
 
My charger won't let me charge from just the balance connector, I thought that was weird. It gives me a warning of "connection break".
I'm done with the battery, checked the cells today and the bad one is it .95v. This battery isn't worth the time or the potential bad outcome. My house and Savage are worth more then this battery.
 
My charger won't let me charge from just the balance connector, I thought that was weird. It gives me a warning of "connection break".
I'm done with the battery, checked the cells today and the bad one is it .95v. This battery isn't worth the time or the potential bad outcome. My house and Savage are worth more then this battery.

Any charger can charge solely through the balance tap...

You charging one cell individually.... So you'll set you charger to charge a 1s battery and just charge through the balance tap like the video shows above.

If your charger is saying connection break....it usually means you've got a duff bridging joint in your lipo battery, commonly the solder cold breaks, giving this error
 
Any charger can charge solely through the balance tap...

My main charger cannot. If I try using just the balance tap, it beeps at me and gives me an open connection error. I am forced to use the main lead and the balance tap if it's a lipo. My charger won't let me charge a 1 cell lipo, 2S-6S only. It's a Dynamite 4x10A/4x100W charger, DYNC2050.

I have another very low wattage (25W I think) 2s/3s charger that charges only with the balance tap. I use that for my super small lipos for my Losi micro sct and micro high roller 2S packs.
 
My main charger cannot. If I try using just the balance tap, it beeps at me and gives me an open connection error. I am forced to use the main lead and the balance tap if it's a lipo. My charger won't let me charge a 1 cell lipo, 2S-6S only. It's a Dynamite 4x10A/4x100W charger, DYNC2050.

I have another very low wattage (25W I think) 2s/3s charger that charges only with the balance tap. I use that for my super small lipos for my Losi micro sct and micro high roller 2S packs.


Dude, you've misunderstood

I don't mean just plug the balance lead into the balance port....

You use the two main leads from your charger - pos and neg - not the balance port..... make a connector from a servo lead and charge using your main pos and neg wires straight into the balance tap..

Its all in the video above
 
Go to 3:30 in the video and keep watching
 
Dude, you've misunderstood

I don't mean just plug the balance lead into the balance port....

You use the two main leads from your charger - pos and neg - not the balance port..... make a connector from a servo lead and charge using your main pos and neg wires straight into the balance tap..

Its all in the video above
Yeah, I didn't watch it. lol

When I was forcing a cell to charge, I did what you suggested, made a connector, then tapped it into the balance port with my old NiMH charger at .5A until the voltage was up where the other cells were.

I think I just read what you were saying wrong.
 
Back
Top