I’ve read a lot about how lithium ion cells last longer when you don’t charge them to 4.2v, or discharge them too low. I know that heat strains batteries over time.
I’m just wondering what makes the biggest impact between charging below 4.2v, shallow depth of discharge, low amp cell load? I’m primarily talking about 18650’s and specifically Samsung 30q’s.
If anyone has experience with this please chime in!
On endless sphere there is a guy name Padja that works daily with batteries and tests them in lot of scenarios
According to him the 30Q doesn’t benefit by charging to lower voltage unless you drop bellow 4 V, also the discharge rate doesn’t have that much of a influence
You can track his posts there for a lot more information that I don’t remember
In short, the 30Q is a cell made for power tools, so it can take a lot of abuse, high discharge and charge currents, but has a “short” life of around 500 cycles and them dies really quickly no matter how much you took care of them
His words
I’m using them for the first time now so I can’t say for myself
@Flasher please no, I beg
Just saw @PXSS saying he is back, he may have more data on it also 
Ill just leave this here.
Ok, so interpreting this graph, I understand that 25%-75% charge-discharge can nearly double battery life under similar tenperature, but keeping them cool will make them last forever. Is that what you got out of this?
I looked into this a while ago but had a sudden realisation late at night
the idea that i should only use 80% of my battery now to save myself having only 80% battery a year from now is fucking ridiculous. life is too short. just charge and ride.
PREACH!
I personally don’t care, as long as I get a year or so out of a battery pack I call it a win. I build and rebuild so much, the configurations change so much, it just doesn’t make sense to worry overmuch about cycle life.
Everything really depend on what battery you are talking about, even if they have the same base chemistry the details make all the diference
But generally yes, cool is better, but if you want to extract the maximum performance hot is better since it lowers internal resistance
Naturally, we all have differing opinions on how important battery lifetime is relative to all other esk8 components. However, I’m also interested in how battery life can be extended, if only from an academic point of view.
FWIW, I think vibration will kill a battery before charge cycles take over. 1000 charge cycles at a conservative 10 miles per charge is some 10k miles…
There are a few papers on this, vibration definitely made the internal resistance go up a lot, it doesn’t make the capacity go down by itself, but make it useless for high power applications
I’m just talking about the controled study they used to produce that graph (TLDR).
it is facinating to me that a battery can last as many charge cycles (at least theoretically)
I want to revive the thread because I am looking for some input on 30Q vs MJ1 in terms of cycle life for a commuter board? Cells not pushed too hard.
Also I saw an interesting thread on cycle testing where they tested several cells, they all lose a little capacity from each cycle, but the tesla cells would gain back capacity if rested between tests, sort of self healing. Really interesting property.
