I was at our dirt oval track sat night,and a friend and his son had both there cars quit.The batts were losi 7.4/5000, I put them on my Ice and neither would take.Both were bulging,my question is does that occur from over charging or draining and can they be salvaged.Thanks

That happened to my core rc 5000 lipo pack and was told not to charge or discharge it, basically don't mess with it. It was a brand new pack with two charges. The last charge, I ran it down to 6.0 volts then charged it right away. A day later, I noticed it was swollen up. I posted on another forum where the guys hanged out and they took care of it.

So contact the manufacturer of the lipo pack, explain what had happen and hopefully they will stand behind their product. Oh, don't mess the lipo pack....

I was at our dirt oval track sat night,and a friend and his son had both there cars quit.The batts were losi 7.4/5000, I put them on my Ice and neither would take.Both were bulging,my question is does that occur from over charging or draining and can they be salvaged.Thanks I've seen one that swelled from charging on NiMh at 9 amps! The owner didn't notice the charger settings until his race was up,so he sat that one out. So,"yes", it would occur from overcharging,or damage to the innards. I have little experience w/ LiPo's but if it was my battery,I wouldn't use it ,as the battery innards may be so messed-up from the overcharging that any further charging or use would be extremely dangerous.

Swelling can result from overcharge, overdischarge, a crack in case (hard case) in wreck, or a short between plates inside the pack.

Swelling can result from overcharge, overdischarge, a crack in case (hard case) in wreck, or a short between plates inside the pack.

WARNING ___________________________________________
If the chemical from a swelling battery comes in contact with the air
it will start a flame out.

Do not use.
Its basicly junk!

Thanks!! it just seemed weird that both batts/father and son crapped out at the same time.I will pass on your info.Myself and a guy I race with hooked them to our Ice chargers and both chargers would not let the charge cycle start,must be good chargers:)

From the description it sounds as if they were over discharged.

From the description it sounds as if they were over discharged.

Not always the case.
Swelling can come from a short between the plates with a regular
charge on a lipo charger.

Most tracks use lipo sacks or a metal pan as they charge up a lipo pack to contain any lipo flame out.

Safety first!

This is the reason you always need to balance your packs. As the cells drift apart, one cell will start to overcharge or overdischarge even though the whole pack might read within tollerance and not trip any protection on the charger or speedo.

My MaxAmps packs are the worst when it comes to balance issues. One weekend of racing put the pack almost .4v out of synch on a high amp draw brushless system. The last time this happened, it took 3 days to balance back out.

Not sure who makes the Losi packs.

It basically is a sign that something is wrong.

I have had packs swell if you have something causing a high amp draw. Low turn brushless and a bad wire = swollen battery for me.

1. I would not recommend taking them down to 6 volt. Seems like newer ones are recommending 3.2 per cell at the bottom end. If they do not have
a lipo cutoff they are asking for trouble.

2. Check battery temps after runs. Mine rarely get much above ambient temp. If they are getting close to 140 there may be an issue.

3. Make sure you check for short possibilities. If you are close to the max amps and your fan is on the crapper and it shorts it may pull enough ams. Bare spots on wires and plugs?

4. Check charging proceedures. Make sure they are using a good lipo charger
set in lipo mode. Make sure the correct # of cells. Max of 1c charge rate.

5. For extended battery life quit charging on the last 5% of the batters.
You know when it shows 8.4 volts and starts dropping the amps.

6. Storage - I store mine from week to wee at about 1/2 to 3/4 charged.

Are they running them down to 6 v and leaving them like that till
the following race weekend? That could be causing an over discharge. Are the storing them at full charge for a long time? I tend to store my lipos in the 1/2 to 3/4 range between races. It is not an exact science as to what mah is in them so that is a good range. So far it seems lipos like to be used. Storing them for 3 months means you need a balance(Mine did) and
take your time using them. Check them rebalance. In 2 years I have had 2 puff packs. One was I lost a connection to a cell. The other was stored and I did not balance before using it hard. This second one could have been avoided.


Of course they could just have bad packs.