Live cycles lio-on battery

[jpc6000]

Electric cars , they say the battery can work 10 years. Like Tesla.
Li-ion battery can 500 to 1000 cycles
(100%, 90% or 80% full charged)?
Example
drive to work 50km
Battery full 100% after 50km 90% full
On work, Charge again to 100% (not good I think but every body does it.)
Drive to home 90% load again to 100%
2 times load every day
Normal after 2 to 3 year the battery should be end live. No?
Is this good, charging the battery only used 10% or 30%?
When charging, is that every time, a charge cycle?

 

[flippy]

cars are desinged to last 20 years, your phone -needs- to die after 2 so you go out and buy a new one.

and yes, cars only use 80~90% of their capacity so the battery last longer.

if you dont need to use the full battery you should set the car to only charge to 50~60% for example. the lower the charge the longer the battery lasts.

 

[batteryGOLD]

18650 cells can live more than 25years

cycle life depends on some variables:
-keep cells temperature stable, tabs cooling.
-charging limited , cell rated at 4,2V charging to 4,0 will triple cell life, so lithium 600cycles will go 1800cycles, and 1k cycle cells will go 3k cycles.

This is easy by adjusting top voltage charger.
example, a battery 10S 42V will triple life cycle if you charge it to 40V, means 4V per cell

The other thing to have more life is not going under 20% state of charge.

so if have battery 10Ah , limiting to 4,0V per cell charge, and only use until 20% state of charge, battery will only have a real capacity of 70% means a 10Ah will go to 7Ah but will triple cycle life

 

[jpc6000]

The question is not so clear
what I mean is,
I load 18650 battery to 4V (80%)
Battery discharged to 3.6V then charge battery again to 4V
(here I charge two times)

Or is it better let the battery to go to 3V and then charge to 4V
(in this example charge one time)

battery live 1000 charges, so the second example should life double longer or not? :?

 

[flippy]

depends on how fast you charge.

if you can deal with the capacity loss you should use the cell between 3.2V and 3.8V for example. it gives the same capacity as 3.6~4V but the lower peak voltage increases the lifespan.

80% of the energy of a cell is between 3.3 and 3.9V.

 

[jpc6000]

I charge always as low as possible, sometimes 20 hours for pack
the lifespam in the first example is this 2 times more then second or not
2 times from 3.6 to 4V lets say 2 times every week, lifespam 2 years
and second example, one time from 3V to 4V one time every week, lifespam 4 years
or not

 

[DogDipstick]

I got a Chevy Volt battery in my ebike.

It dont quit. Still just as powerful as it was from day 1. Still registers 1.4mOh / cell on datalog with 0 lost capacity. Pulls ya right up to 50mph. Going on three years. Beat, always fully charged, never babied, even crashed and scraped up.... wet, dry, hot cold, salty, I dont care. I charge at 1 or 2C.. 15 or 30A.. and always up to the maximum allowed.. ( and sometimes over the maximum allowed voltages for .. er... fun... Ya know? Like dont ya want to try 4.35v/ cell some times? Lol 4 real though, dont overcharge on purpose)

Others know this too. Have packs from EV cells that are lasting years, and have lasted years. Since 2012 or so, I bet there are some A123 packs still kicking.

I bought another battery too. Brand New 2019 Chevy Volt. 0 miles, and I expect it to reach its 8 year, 80,000 mile easily. Bout to rip it down for ebike packs. I aint even baselining the whole thing. I am gonna pick one module, and baseline it, that is it. Just gonna build with the others.. No pre testing. They are new. Uniformity and quality.

Ask me again in 2029, and I'll tell ya how it went.

If undercharging ( to 4.0v/cell) will " double the usable lifespan"..... ( # of cycles).... you would expect like... what ....at least 16 years of use?

Ask me again, how it went... in 2037 pls.



Nothing touches the quality or EV cells designed for highway use. 18650 are a joke compared in the power, energy, and longevity properties.

A full cycle of the battery is use of its entire capacity ( 1 cycle) even if over a few iterations.

1/2 charge + 1/2 charge = 1 Cycle.

1 ( full charge) = 1 cycle.

1/3 + 1/3 + 1/3= 1 cycle.