discharging batterys

[furylemon97]

Hello everyone,

 

Just looking for some advice on what V to discharge my 11.1 3s lipo battery and my 11.1 3s Li-ion battery and what Amps to discharge at?

[Adolf Hamster]

why do you need to discharge them?

[BigStew]

Lipos don't need to be discharged you run the risk of running them flat that will wreck them.

[furylemon97]

dont they need to be discharged to be stored away?

[Adolf Hamster]

1 minute ago, furylemon97 said:

dont they need to be discharged to be stored away?

 

depends on how long you plan on storing them for, but generally if it's less than a month then there's no point.

[furylemon97]

yes i dont think ill be playing much till next year when the weather starts to get nicer 

[Rogerborg]

I don't bother myself given the cost vs benefit vs my time, but I've come round to being convinced that storing somewhere below maximum capacity is probably a good idea as there could be some chemical unpleasantness if you leave a lithium cell fully charged.

 

However, I'm not even sure what we're looking at in terms of voltage, given that a typical charger will pump cells to 4.2V rather than the nominal 3.7V, and that voltage and capacity aren't a linear relationship.  70-80% of maximum charge would mean a cell voltage of something like 3.95 - 4.02V, but I doubt that's what a charger will set as a storage voltage (and it can only see the voltage and resistance, not the actual charge).

 

I'll storage charge a 2S on my B6 and see what it settles down at. I've never done this before, I reckon I'll see something like 3.8V per cell / 7.6V, which would only be  about 40% charge, but I'm all tingly to find out (or that could be bad earthing).

 

[UPDATE]

 

Yup, 3.8V per cell, or about 40% charge. I'm surprised it's that low, I used a lipo that hasn't been charged for many months, and it still had to discharge it down from 4.0V per cell.

[EDcase]

If you have a decent charger there will be a storage charge option.

That will charge or discharge to the correct medium level for long term storage.

[Lozart]

2 hours ago, furylemon97 said:

dont they need to be discharged to be stored away?

 

As mentioned, ideally they should be put to a storage level but it isn't absolutely necessary.

 

33 minutes ago, EDcase said:

If you have a decent charger there will be a storage charge option.

That will charge or discharge to the correct medium level for long term storage.

 

If you don't have a decent charger, get one.

[Rogerborg]

I'm still shocked and stunned that a "decent charger" thinks that a storage charge is so low. I'd always been told 80% by real internets experts, but SkyRC reckon it's half of that.