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question on cycle life of battery

Sam1

Active Member
Sep 11, 2019
1,129
1,004
NV
The estimated 1500 cycles that the battery is expected to last through, do you calculate that by adding both the charge and discharge cycles? Or does it only consider the discharge cycles?
 

camalaio

Active Member
May 28, 2019
1,483
2,106
Vernon, BC, Canada
Just one, not both. Not entirely sure which one is better to go by though.

In terms of cycle count, charge and discharge will be slightly off (by more than just the one cycle you'd expect). For example, I was recently around 106.1 discharge cycles (estimated) and 110.2 charge cycles after a full charge. I won't speculate on all the reasons why this is, someone else probably knows better.

Anyways. Yeah. Just one.
 

Sam1

Active Member
Sep 11, 2019
1,129
1,004
NV
Well, the reason I ask this would be because charging it up seems like it would be considered wear as well. If it's not, what makes a discharge worse than a charge as far as wear and tear go? (Not including supercharging)
 

Rocky_H

Well-Known Member
Feb 19, 2015
6,660
7,951
Boise, ID
It's called a cycle because it is one of each, not just a one direction thing. A cycle of a battery is defined as the full capacity of the battery drained and refilled again. That can be done many different ways, though. It's still just one cycle if you drain half and refill that half twice. Or a tenth ten times, etc. And not all cycles are created equal if you are doing this at various temperatures or doing this near the top or middle or bottom end of the battery, etc. There is a lot of research about it, but a cycle is a pretty simple definition.
 

TMThree

Active Member
Mar 28, 2019
1,118
1,616
USA
Range of 310 miles * 1500 charge cycles = ~450,000 mile estimated lifespan.

Thing is, charging from 40% to 60% daily is significantly less than 20% (charge cycle) of the actual capacity being used would lead you to believe.
 
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Sam1

Active Member
Sep 11, 2019
1,129
1,004
NV
Range of 310 miles * 1500 charge cycles = ~450,000 mile estimated lifespan.

Thing is, charging from 40% to 60% daily is significantly less than 20% (charge cycle) of the actual capacity being used would lead you to believe.

yes I understand that. SMT was showing I had roughly 250 discharge cycles, and 255 charge cycles right before 12 months. Was thinking that would be really high (30% of expected battery life) if they counted each type of cycle independently.
 

TMThree

Active Member
Mar 28, 2019
1,118
1,616
USA
yes I understand that. SMT was showing I had roughly 250 discharge cycles, and 255 charge cycles right before 12 months. Was thinking that would be really high (30% of expected battery life) if they counted each type of cycle independently.

We know every little recharge won't matter. Regen happens dozens to hundreds of times per car ride and those events all push energy back into the cells.

There are just so many cells that these partial charges barely matter to the individual cell since its spread out so much
 

Rocky_H

Well-Known Member
Feb 19, 2015
6,660
7,951
Boise, ID
SMT was showing I had roughly 250 discharge cycles, and 255 charge cycles right before 12 months.
Then they are using the term wrong. Those would be charging "events", not charging "cycles".
Range of 310 miles * 1500 charge cycles = ~450,000 mile estimated lifespan.
Yes, that is how you count the amount of cycles in a very general ballpark estimate kind of way. Rated miles are not exactly real distance miles, so there's some 80-90% kind of fudge factor to that because no one drives like the EPA, but yes, the full range of the car times number of cycles is it.
 
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Reactions: jjrandorin

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