LiPo Battery Self Discharge

Hi there,

I remember reading somewhere that LiPo batteries with higher discharge current ratings (25C for example) have higher self-discharge/leakage currents than LiPo's with lower current ratings, like 1-2C. Is that true? I'm just wondering if I should or should not be using quadcopter batteries for my low-power devices.

Thanks!

I think you'd have to check the manufacturer's data sheet(s).

A self-discharge spec is going to be "worst case" for a new battery (although the datasheet may also give a "typical" value). In other words, some batteries may be better and self-discharge much more slowly than the spec. That's assuming a reliable manufacturer... Not the cheapest thing you find on eBay... :wink: Then, as the battery ages it's likely to get worse.

So there's no direct correlation between the "C" rating and self-discharge?

Also, what would be the self-discharge rate of this battery's spec sheet? (See page 5). Looks like it lost 15% in 6 days? That can't be right. It should be around 5% a month.

No, what it says is that it will count as a fail if it loses over 15% in 6 days. My guess is it will be normally be a lot less but why they specify it like that is anyone’s guess.

If it helps I had an old 8C battery which lost less than 25% charge in approximately 2 years (I forgot about it ;)). And most of my current 20-30C lipos will lose no measurable charge at all in a week, though I try not to store lipos fully charged as it does them no good in the long term.

Steve

Yea my 1C LiPo's from Adafruit don't measure any loss over weeks like you said, but I'm mainly wondering if higher "C" ratings will either have higher or lower drainage rates. I think overall LiPo's in general have low self discharge rates, but I'd still be curious to know if there's a correlation.

I have some small (80mAh, 15C) LiPos and they seem to hold charge for ever.

...R

Thanks for the discharge info for higher "C" rated batteries! I think I can safely assume that they'll be just fine for my applications :slight_smile:

You may find this discussion of self-discharge useful.

Thanks! That was helpful. Seems like 5% discharge per month with the protection circuit is typical of LiPo's. I'm starting to think that the discharge rate doesn't depend on the "C" rating.