Do multiple small recharges ruin the battery as fast as full charges?

[Bruno Vincent]

A laptop battery usually lasts about 500 charges ?

But is that from empty to full?

Is it 500 charges from when laptop is empty?

How about if you run the latop to 80% battery, and then recharge the 20% left?

Doe that mean a cycle per 20%?

Or does it mean 20% * 5 = 2500 charges?

Does 500 charge cycles at 100% = 2500 charge cycles at 20%

I hope it's clear enough 😉

 

[Someone Somewhere]

I think that's about right.

However, being at the extremes of the range tends to do more damage than the centre. So going 100>80>100 would cause more wear than 60>40>60.

So it might be more like 1500 partial cycles, because the battery is being charged and discharged frequently when near full.

 

[Solandri]

Bad:
Deep discharges
Charging to or near 100%
Discharging to or near 0%
Heat

Good:
Shallow discharges
Charging or discharging in the region away from the extremes (0% and 100%)

http/batteryuniversity.com/learn/article/how_to_prolong_lithium_based_batteries

The reason is that as you charge the battery, the anodes grow and distort as the lithium ions carry charge to them from the cathode. Extreme charges appear to damage the physical structure, reducing charge capacity for future charges. Shallow charges result in less physical distortion, and thus less damage. (Video)

http/bcove.me/581iaz9a

My previous laptop had a battery-saving feature which stopped charging at 80%. I turned it on within a few weeks of buying the laptop. I also almost never discharged the battery to 0%. When I bought the laptop, the battery would last about 2h 45m. When I replaced it 5 years later after probably 1000 cycles, the battery still lasted 2h 30m. So shallow charges and not putting the battery near the extremes works.

Please note that a lot of the newer laptop batteries seem to have this functionality built in. If you look at the "battery health" stat with a tool like HWINFO or HWMonitor when the laptop is new, the battery will already show about 5%-10% wear. I believe that's how manufacturers are tricking Windows into not charging the battery too much - falsely reporting the battery's current capacity as less than its actual capacity.