Lipo Battery taking forever to charge

[Shinjari]

Heres the story, I purchased (3) GForce 25C 1300mAh 3S 11.1V LiPO SKU: SHD-LP-2656 and have balanced charged them when I received them. During this initial charge I noticed that 1 of the cells in each battery clearly had more internal resistance as it would not balance properly, 2 cells would be at the 4.20v whereas this cell lingered around 4.13-4.16v until it eventually caught up an hour later. This happened for each of the 3 packs. I then ran the battery packs in my Axial SCX10 until the lipo shut off kicked in. I went to recharge them today and now the problem seems to be worse than the first time I charged them. I charged it at the recommended 1c (1.3A) and after 2 hours my charger had said it had charged the battery for nearly 1400mah (only 1300 mah capacity?) and now the cell that lingered is even worse at 4.10-4.14v range. In fact I am currently balance charging one as I type this and the voltage on 1 cell stays at 4.20v, one cell jumps between 4.18-4.22v and the last cell is between the 4.10-4.14v. A similar battery I have is the genace 3s 1300mah and it charges at 1c in roughly 45 minutes to an hour.

I have used this charger on many other batteries (500mah-6500mah & 2s-4s) from turnigy, gensace, thunderpower and sky lipo and experienced no issues charging them.

The question I have is, am I doing something wrong? Are most of the batteries like this? Are these poor quality batteries? I read that smaller capacity batteries have a higher internal resistance but geez 2-3 hours to charge a 1300mah at 1c?

Was considering returning them and just buying my tried and true turnigy nano-techs or taking a chance on zippy flightmax since they are even cheaper...

Any help would be appreciated. "thumbsup"

 

[rcmedic]

Very poor quality batts, Turnigy 2200 30-40c 3s's $11 bucks, and i run them HARD!

 

[Olle P]

The one deviating cell seems to have been bad from the beginning, holding very low capacity.
When you used it it would deep discharge before the LVC kicked in, making the problem even worse.

 

[johnnyh66]

My GForce batteries do seem to take a long time to charge but they are so cheap I don't even balance them anymore...

 

[Duuuuuuuude]

Very poor quality batts

Not at all true. GForce is pretty much all I have used in my crawlers and sc rigs for the past 4 years. Very rarely is there a bad cell out of the box.

 

[Shinjari]

I mean they work great when charged....just seem to take longer to balance than my genaces/turnigy/skyblues. I balance every time and I guess since that one cell is 'off' it takes forever, wonder how long it would simply take to 'charge' if I wasn't trying to balance. Thanks for the input so far, still torn on whether to return/exchange them.

 

[Duuuuuuuude]

Are all three like that, or just one?

All three would be extremely odd.

 

[Shinjari]

To be honest i think its really just one, not much I can do besides run them and charge them again to see if it is indeed just the one.

 

[CREEPINKING]

I've got about six of the 60c 3s lipos in 1300 and 2200 and I've noticed all of them take forever to charge. I haven't noticed any voltage difference between the cells but I'll pay a little closer attention during a charge now. I figured I was just getting more and more impatient the older I get. Glad I'm not the only one that has noticed the charge time.

They all run great and last just as long as any of my other comparable lipos. Just takes the better part of the day to get them all charged up again.

 

[Shinjari]

Yeah they ran just as long as my others, just took significantly longer to charge. Then again now that I think about it I think I may charge my others at 1.5c but since these said only 1c that could be part of it too....still doesnt explain the voltage difference besides high IR's in the cells.

 

[Olle P]

It could be a higher resistance in one of the balance leads (due to for example poor contacting).

 

[Trubble]

When I ordered up my 4 G-Force packs, one of the packs had a funky cell and wouldn't charge properly. I made an adapter with pins on it, set my 230 to one cell, and charged each of the three cells independently through the balance connector. My balancer is a charge-through balancer, so I charge at 2C through the balance connector. My suspect pack is identical to my other packs except for being marked with a Sharpie on the end (and actually is my 'go-to' pack).

Could just be your cell was/is further gone than mine. Let us know if you get something figured out.

 

[Hatersauce]

I started using the Turnigy batteries for my Slash and they have been working great so for me. And $20 for a 5000mah, 25c discharge battery ain't bad. But I don't balance every time I charge, though. Probably every 8-10 times and they have worked fine without problems. I have 3 2000mah venoms I will probably try when my kit is built, though. Just because they are small and light.

 

[Manning]

This will seem counterintuitive, but try charging at a lower rate. Most chargers balance by switching in resistor on the high voltage cells, and this resistance usually only amounts to 300-500 milliamperes. So if you are charging at 1300 ma, the high cells are still getting 1000 ma even when balancing.

I've got one craptastic 2200mah pack that has had one 'bad' cell from day one. If I try to charge at 2amps or more, the chargers basically shut off before the bad cell is fully charged since the voltage on the bad cell goes sky high. But if I charge at 1 amp or less, everything happens like it should. The pack works fine in a scaler. I wouldn't use it for racing or in a plane/helicopter .

Today's cheapo lipos are wonderful for the most part (I wouldn't want to have to run Ni packs ever again), but bad new packs do exist.

 

[Shinjari]

Thanks for the replies everyone, the pack eventually charges completely to 4.2v to each cell, but it takes some serious time like 2-3 hours. Maybe I'm just impatient lol. For $10 a piece its hard to complain. =)