Looking after your LiPo cells

[Mike Rieder]

Thought i would share my latest build (felt this was the most appropriate topic to add it too). A charging cupboard made from fire retardant plaster board. Hopefully it should save the rest of the garage if anything goes wrong!

[Francis Focar]

What does anyone think about the B6 and using the lilo setting that will charge to 4.1 per cell ??

[ARC]

Has anyone had success in restoring a weak cell by discharging at 0.5amp until all cells are even and then balance charge at 0.5.

Have recently tried this and all cells on my 4s 5000 mah 20c are now at 4.20. Not sure on the longevity on this but it appears to work

[Biggles' Elder Brother - Moderator]

Hi ARC, I will present a variant on this idea in the next issue of the magazine, I think you may be interested!
BEB

[Sam Longley]

Posted by Tim Mackey on 01/02/2008 12:50:00:

Using them cold of course is different - they perform very poorly if cold - very noticeably in EDFS etc, where every little bit helps. I always warm them in the car or my inside pocket before fitting and flying.

Edited By Timbo - Moderator on 18/08/2009 19:10:15

I have just read the first part of this old thread. Are you really telling me- as a beginner, as far as electrics are concerned- that I can walk about with these in my inside pocket???

I asked because I watched my (Senior BMFA) instructor place one on a table ( It was fitted to his starter). Someone said " Watch out that is going to blow"-"Nah! it is OK" a few moments later it exploded & burned a hole through the table, before falling to the ground.

So what would that do to me?

[David Holland 2]

I have just read, on a model engineering forum, that lithium cells can be “revitalised” by a spell in the freezer. This sounds most unlikely, does anyone know any basis for this. Might just try it on a pack relegated to second line duties.

David

[Simon Chaddock]

It surely depends on from what state the LiPo is at and the degree of "revitalisation" expected.

A LiPo starts to deteriorate from its date of 'activation' during the manufacturing process.

[Nigel R]

"This sounds most unlikely, does anyone know any basis for this."

I have never heard in any professional capacity of any mechanism for "revitalising" lipo cell chemistry.

All the related effort goes into slowing any deterioration effects.

[Bob Cotsford]

I've heard of cells being put in the freezer to reduce the level of inflation once they've gassed but I've never found it to be very effective. A charge or two and they swell again. Preventing long term storage problems is another matter, in theory the lower temperature should reduce any aging effects.

[MattyB]

Posted by David Holland 2 on 19/10/2020 09:14:23:

I have just read, on a model engineering forum, that lithium cells can be “revitalised” by a spell in the freezer. This sounds most unlikely, does anyone know any basis for this. Might just try it on a pack relegated to second line duties.

No, it's complete twaddle. The degradation mechanisms that go on inside the lipo (dendrite formation for example) cannot be reversed by a simple drop in temperature. Not storing at high temperatures and elevated SOC will slow the rate of degradation on the shelf, but there is nothing known at this point that you can do to reverse internal damage to a pack.

[Chris Walby]

I though you damaged lipos by storing or using them at low temperatures (below 10 C), only newish pack that I used (stored in car overnight with a frost on it) resulted in a cell failure. Since then keep in garage and use warmer to ensure they are above 15 C before use.

[Nigel R]

It is not good to do a high discharge from a very cold lipo. The internal resistance increases sharply below 10deg, so if nothing else you'd get an short and listless motor run. I can't remember offhand what the sensible cutoff for low temp storage is, but, the slowest degradation is seen at around 7 or 10 deg, I believe.

[cymaz]

Could someone how lipos are recycled safely? As they have the ability to explode we just can’t leave them lying about. And there’s not an infinite supply of the minerals.

[Nigel R]

At our end of things, discharge and then to the council recycling centre.

At the other end, who knows.

[brokenenglish]

This looks like an appropriate place for my question...

I recently crashed on the first take-off of the day, and did visible damage to the Lipo (3S 2200 mAh).
The outer plastic is very torn and the actual pack has been bent into an "L" shape.
The cells are still intact and I don't think there's any imminent danger.

However, the battery is fully charged.
Before disposing of the battery, should I discharge it through my charger?

[Dickw]

I would dicharge it through your charger followed by discharging to completely flat (0v) with a 12v bulb (I use a car tail light bulb). Just do it some where safe, and treat it like it is about to burst into flames until you have it completely flat.

Dick

[MattyB]

Posted by cymaz on 20/10/2020 06:04:08:

Could someone how lipos are recycled safely? As they have the ability to explode we just can’t leave them lying about. And there’s not an infinite supply of the minerals.

As long as you fully discharge them there is essentially zero chance of an explosion. I can find very little online about the processes used to recycle them though - it does make you wonder whether in the end they all end up in landfill anyway, or worse on a beach somewhere in Asia like so much of our "recycling"...