Stored Lithium-ion batteries self exterminate after 2-3 years?

[anorlunda]

That doesn't take into account that there is probably some amount of maximum amount of charges possible before the battery/phone/ breaks down

I think you are trying to take those statements too literally and expecting more precision than is possible.

Cycles are a factor in life, so is state of charge, so is temperature, there may be other factors. Then, holding all those factors constant, there will be a random distribution of actual lifetimes. The random variance may be larger than the named factors.

In the case of Apple, it sounds like they threw a number out there for lifetime in cycles without mentioning other factors. Then some non-technical person pressed with customer questions about what defines a cycle just made up a bunch of words to make the question go away. IMO, one should take all those things with a grain of salt.

 

[CWatters]

Suppose I charge every 10% for maximum amount of cycles. That doesn't take into account that there is probably some amount of maximum amount of charges possible before the battery/phone/ breaks down, making the increasing cycles irrelevant.

Look at it this way. Let's say you currently recharge every night. A reasonable question would be …

Q: Is it better to recharge at lunchtime as well, even if you don't need to? Will this give your battery a longer life (eg more years).
A: The answer appears to be yes...

Lets say you currently charge at night and run you phone down to 20% remaining during the daytime. That's a DoD of 80%. Table 2 reproduced below says that if you keep doing that your Li battery will last about 900 cycles = 900 days.

Source:https://batteryuniversity.com/index.php/learn/article/how_to_prolong_lithium_based_batteries

However if you recharge at lunchtime as well your average DoD will only be 40% and your battery will live for 3000 cycles. However you would be doing two cycles a day instead of one so that works out at 3000/2 = 1500 days.

So by charging twice a day instead of once you might increase battery life from 900 to 1500 days.

PS: Figure 6 at that link also explains that you can also gain battery life by not fully recharging each time. In other words try and only use the "middle" part of the cells capacity. Easier said than done.

 

[Pleonasm]

Look at it this way. Let's say you currently recharge every night. A reasonable question would be …

Q: Is it better to recharge at lunchtime as well, even if you don't need to? Will this give your battery a longer life (eg more years).
A: The answer appears to be yes...

Lets say you currently charge at night and run you phone down to 20% remaining during the daytime. That's a DoD of 80%. Table 2 reproduced below says that if you keep doing that your Li battery will last about 900 cycles = 900 days.

Source:https://batteryuniversity.com/index.php/learn/article/how_to_prolong_lithium_based_batteries

View attachment 236665

However if you recharge at lunchtime as well your average DoD will only be 40% and your battery will live for 3000 cycles. However you would be doing two cycles a day instead of one so that works out at 3000/2 = 1500 days.

So by charging twice a day instead of once you might increase battery life from 900 to 1500 days.

PS: Figure 6 at that link also explains that you can also gain battery life by not fully recharging each time. In other words try and only use the "middle" part of the cells capacity. Easier said than done.

But don't you think its a very clear finite number of times the battery can receive the voltage input (charging)? Can a Lion Battery withstand daily top-offs for years,? Say I recharge a lion battery 10% 10 times every day for years, you don't think it will break down sooner from overcharging, than if I only charged it once every three days (suppose my usage was limited).

 

[anorlunda]

@Pleonasm , you are exhausting the patience of people who have been trying to help you with 93 posts on this simple question, yet the last post circles back to the first.

The answer to every one of your questions can be found at batteryuniversity.com.

Thread closed.