LIPOs lost punch
 

What would cause this? LIPOs haven't been used for a while, but were all charged.

Approximately how many cycles have they gone through? How long were they left fully charged?

I think they were left for a couple of months, not sure. Haven't run 2WD for a while.

Not sure on the cycles again summer seasons worth racing each weekend.

Discharging one at the mo to then recharge and balance it.

Downside of having 5 packs of LIPOs is that they are cycled enough.

Looks like a trip to the tip and time to purchase another Speed Passion 5300.

If you took them from storage and just ran them they will feel off. Just charge and run them a couple of times and they should come back.

They don't like the cold either, so if you were trying them outside they will feel crap as well. If you have to use them outside try sticking them in your pocket for a while first :)

Ok thanks for the info.

I'll run them at our club, but it looks like I'll be running with Speed Passion at Petit as I need consistency.

If you left them fully charged there is a chance they have gone funny. I left a SMC 5000 28C pack fully charged for a few months and came back to it being puffed.

Nothing has puffed. I'm going to charge and discharge them and then see how they are.

Thats good at least, keep an eye on them when you charge them as that is when it is most likely to swell.

Will be using the pouch for the moment.

I've charged one and discharged it and put it in the car. Still lacking Punch. :cry:

5 lipo packs?

I run 1 per car

That's what I'm plan to be doing, but I have 4 x Trakpower for the Losi XXCR with a mate as they are a perfect fit and 1 x Speed Passion 5300s for the Cat SX

What I'll prob do is Speed Passion 5300s for the B4 and Cat SX

Then not sure what I'll do with the XXCR. Go back to NIMHs and brushed!

give them some cycles im sure they will come back maybe dodgy charger?

If you are not using lipos for a couple of weeks, they are best stored at about half charge, around 3.8-3.9v per cell. If they are left fully charged, I have read that temp variations could lead them to go slightly overcharged, which can damage them. I had a Thunderpower flight pack puff after 5-6 cycles, despite being balance charged every time and being stored half charged. It was replaced luckily, and the new one fine. Probably just an unlucky pack.

I'd say the cut-off point for storing fully charged is about 1 month, I'm not surprised they've been affected.

In fairness though, with some cycles through them (at least 5) they should regain some of their former punch - all is not lost yet!

Lesson learned and new lipo inbound

have the Pro-Trak which I'm using as I type to charge/discharge/monitor a pack of mine that's been stood for a good 8 months if not more, not sure how they were stored apart from in the garage :woot:

results later will be posted later :thumbsup:

This will be interesting.

What make of LIPO is it?

FlightPower EVO25 3700 and had it since 2007 ish but not used a great deal. Been in B4 / T4 / TT01 and given some stick on a Mamba 7700k motor in RC10 T4.

Got some SMC 4k LV cells on loan and for sale. Agian haven't seen a lot of use. Used at the weekend but looks like I cocked up on esc settings as other lipo's gave the GT10 the same results. ESC now sorted and the 17.5 motor spins upto at least 40K. See it on YT using Novak Sentry Data Logger, click on link in sig line.

i callled trackpower today and had a lengthy chat

when storing lipo your not suposed to store them fully charged this will give you a damaged pack/lack of punch.
you can recover some by cycling, but they will never be the same.. trakpowers come to you 70% charged, they do that for a reason, also why good chargers have a "storage" mode.

so store them partially charged, ie after a run, dont top them back up, but leave them till next time


hope this helps

Mark

check them out here

there's a bit of voltage difference between them 0.07 / 0.09

during the charge mode I ramped the amps up & down but there's no change in pack volts like you would see if doing sub c cells

discharge rate is fixed at 30amp to 3.1v per cut off