JIM1

Hi,

Has anyone had bad swelling problems with their hardcase SMC lipos?

I have had a pair of SMC 2s 40c c-max lipos for a little over 9 months and they have both started to swell. One is much worse than the other. I placed my Pro10 on it's stand today after a 15 min run when I noticed the car wobbling. I looked under it and the lipo had swollen pushing the battery tray out around 4mm! I have probably only done around 30 cycles with each pack and always balance them and have never hit the voltage cut off on the esc.
I did notice that they had started to swell a little after just a few cycles when I first got them but they have not got any worse until now and thought a little swelling was normal.

Do I need to throw these lipos away and why would this happen? SMC's website looks pretty poor as it doesn't seem to have been updated in a long time as it still says that the C-MAX cells are coming soon when in fact they have been out ages.

Regards.

Jeff Cuffs

iTrader: (2)

You heating your cells and how are you storing them

JIM1

At room temp.

AreCee

iTrader: (1)

I had a problem when two new (less than a month old and with only 2 races) 1S 4900mah packs swelled up in the car while on the track. Not charging but while racing a qualifier and a main. Both had 3.7 volts coming off the track too.

I emailed SMC and Danny Sullivan said that he hasn't had any problems with the packs, I sent them to him anyway for his inspection. About a month later I had two brand new packs in my mailbox.

20 SMOKE

iTrader: (103)

what voltage is it being stored at

FactoryTeam08

I have said it before and will again, sorry but that is my take on them.

Dane

iTrader: (26)

I wouldn't say SMC make bad packs per se but I've seen quite a few swollen SMC packs lately. Make sure you are charging it to 8.4 volts and in Lipo mode on your charger. Take the car off the track if you notice a drop in performance. Lipo cut offs aren't always the best indicator if you're running it too low.

I tested the SMC and Thunderpower packs and I like Thunderpower more. More punch and I haven't seen any swollen packs, even from packs that are over a year old.

JIM1

Not sure if this will apply to me as they are 9 months old. Just plugged the heavily swollen lipo to my balancer and the cell voltages are reading ok.

gettinbrushless

iTrader: (58)

Yeah Im having some problems with some packs also I emailed SMC and they seem to be kinda trying to not take care of the problem Im gonna send my 2 packs that are bad with the reciept and hope they will replace them! I thought by paying the $ for name brand packs was the way to go but now Im starting to think that its better to go with the cheap turnigy packs instead? So Ill keep you updated on what happens.

AreCee

iTrader: (1)

I was just relating my experience with SMC batteries.

BTW I sold those new packs since I had replaced them with Reedys and raced multiple races on the Reedys in both 1/12 and WGT (about 10 races each so the packs had at least 30 to 40 cycles and were strong all the way).

AreCee

iTrader: (1)

Funny you should mention this. I recently converted to 1/8 buggy electrics and bought a 4s hard case from a reliable source for $160. After a few times out and three races I now have a very swollen pack whereas the "cheap" 5S soft packs for my truggy are still going strong at less than 1/4 the cost. I did have on 5S go bad but at $40 I didn't feel bad about throwing it away.

Unless I race at a track that requires the EXPENSIVE ROAR approved batteries I will only use Turnigy/Zippy batteries. Good thing I don't race ROAR sanctioned events.

wingracer

iTrader: (24)

Exact same thing happened to me on only its 5th or 6th run. Swelled so much that it got up into the shock, binding it up and throwing the handling off. I thought I had broken the car.

<PsOp>

I have a friend too that has two smc's lipo that are swollen and I have an old orion 4800 lipo about 100plus charge and balanced once a month that still works fine. I use it for practice or bashing and I'm thinking getting some cheap (price) lipo and dump the name brand that cost 3x more.

JIM1

I think im gonna throw this bloated lipo away and stay away from SMC in the future as they seem pretty poor quality and over rated.

I may try some cheaper lipos such as the Zeppin or some random ones from ebay just to see how they hold up. I bet they are all from the same source anyway?

Nova F1 Racer

iTrader: (3)

Another racer with the SMC pack starting to bloat... less than 7 months, always charged it at 5400 and once a month balanced it....

Still going good but keeping an eye on it....