How Far Do You Discharge Your Lipos?

[FE_Chris]

Was wondering...Now I know the golden number is 3.0 volts per cell, but I have been reading and it seems many people are going up to 3.3 - 3.5 volts per cell. Any real reason for this? What do you guys discharge to and why?

I just set a new ESC I have to 3.3 volts per cell. I figured that was a good comprimise between run time and battery longevity.

[Ub Hauled]

3.3 is where I like it.

[Ctonez]

Can you say how that works out as far as percentage of capacity used/remaining? is that number fairly constant?

[Darin Jordan]

I run my last race of the day, take them out of the boat, store them until the next race weekend, then charge them back up...

[Ub Hauled]

that number is constant, it does not matter what size pack...

[crabstick]

it depends on the LVC settings in the ESC, on 4s I use a 12v cutoff, leaving me 3v per cell.

[sailr]

3.2V per cell. Darin is right. Let 'em rest until just before you run again. Storing them fully charged is bad news for the batts.

[mickvk]

My understanding is that under heavy load (at it's continuous rating for example), running from fully charged to 3.0 per cell will over heat the battery. By timing the battery for half of it's charge or some higher voltage, you wont over heat it.

[FE_Chris]

Huh.....well, i'm just gonna stick with 3.3 per cell. Guess I can't really go wrong with that. Thanks fellas.

[Ctonez]

I'll rephrase, as I didn't quite get what I was after:

After a run, when I put my packs on the charger, my charger tells me what percentage of the capacity remains in the packs...is there a standard percentage of capacity at which the cell voltage drops to 3.3?

My charger also tells cell voltage, but I've never been low enough to see 3.3v/cell, so I can't equate that with a percentage.
I recall awhile ago it was suggested to me that you not run lipos below 15% capacity...does that number still hold true? For all Lipos?

thanks for your input guys...and I believe I'm still on topic.

[Gary]

Well this is what i have found recently. I feel.......in my own opinion and im sure many others will agree, but its possible i could be wrong, that when my batteries are on freaking fire on a SAW run, and smoke is pouring out like the forth of july that im just about at the "dont bother checking voltage" stage of there life.LOL!!!!!!!

[LiPo Power]

3.2V per cell. Darin is right. Let 'em rest until just before you run again. Storing them fully charged is bad news for the batts.

Why is it not good for lipos to sit lets say a week fully charged before use?
Thanks

[mickvk]

Why is it not good for lipos to sit lets say a week fully charged before use?
Thanks

The shelf life of a lipo is I think about three years following recommended storage and usage. I believe they self deteriorate faster if they're stored fully charged for months on end. I don't necessarily sweat it for a week here or there.

Lithium based laptop batteries are similar... It's actually good to cycle them and not store them fully charged.

[LiPo Power]

So week or so is no problem I take it?
How would you store them over the winter before next season comes arround?
Good staff, thanks?
Robert

[mickvk]

So week or so is no problem I take it?
How would you store them over the winter before next season comes arround?
Good staff, thanks?
Robert

This is from Max amps:

Storage: If you don’t plan on using your lipo pack for longer than a week, store it at 50-60% of the pack’s rated capacity. Make sure to cycle and/or balance your packs at least once per month since leaving them on the shelf for a prolonged period of time can cause the packs to get severely out of balance or even go dead

http://www.maxamps.com/lipo-care.php