Balancing Batteries - how to?

[Jeremy Harris]

Thanks for these details Jeremy.

Since I moved, I use around 350Wh/day to commute and almost do a cycle/day on my lipo. So I should do around 350 cycles a year and should have approximatively 2 years of usage of lipo before I throw them away.
I was thinking about getting a Lifepo4 pack but I'm wondering if that would worth it since it also loose 5-10%/year and that I'll have to replace them in 3 years anyway.

I was thinking that the nanotech (or potentially cheaper lipo) may be as good as a lifepo4 in term of shelf life and cycle life under low C rate.

I'm not convinced (only because I've not used them myself) that the more expensive nanotech cells will offer enough extra life at low discharge rates to justify the higher cost. Maybe they will, maybe they won't. My gut feeling is that, as they use the same basic cell chemistry, they may well end up with a life under light use that's about the same as the much cheaper lower C rate cells.

I think that the oft-quoted 5 to 10% per year capacity loss figure may well be on the high side, based on my recent experience. If you choose to only discharge the pack to around 30% or so, then I suspect you may get a longer life and less loss of capacity with time. I've no experience to support this, mind, other than the rather poor single sample of the pack I run on my folding bike.

[SamTexas]

Please stop deliberately twisting things I have written

Depends on whether you want maximum usable capacity or maximum life. If you limit maximum charge to around 4.1 V or so,

Ha ha... Ok. Show me where I twisted your words and I will apologize in public. But if you cannot find those, then you owe me an apology for accusing me of doing so.

[cwah]

Thanks Jeremy. If I only charge to 90% and discharge to 30%, I probably better go lipo as Lifepo4 are already way heavier than them.

Battery are such a huge amount of money (over 1000wh pack), that's a dilemma for me