I wonder if lithium-ion batteries, like those in mobile phones, take damage if you interrupt the charging before it is fully charges. I remember that cadmium batteries needed to be charged fully before interrupting the charge. Otherwise the would charge less the next time.

@Niolator

Li-Ion batteries does not have any "memory effect" like old NiCd batteries. There have been tests (primarily around the Tesla electric car) where it was concluded that to maximize the life span of Li-Ion batteries, one should charge them between 40-80%. This is the best compromise between staying-away-for-extremes and number of charging cycles.

What damage a Li-Ion battery the most is over-change. The built-in changer should make sure that doesn't happen, but they often push close to the border. So overnight charging of a mobile phone is a bad idea, and keeping a laptop plugged in 24/7 is also a bad idea. Also deep discharge they don't like.

Once in a while, a full discharge (as indicated by the device: phone/laptop/car/bike) and a full change is needed to calibrate the battery. Li-Ion batteries has a monitoring chip built-in to protect from over-change in case of damaged charger or misuse. Laptop batteries even keep track of charging cycles themselves.

If a Li-Ion battery should be stored and not used for a long time, it should be charged to 60-80%. Not full, and not left empty.

To answer your question: No. Li-Ion batteries does not take damage by interrupting the charge. Rather, they like it.

Nominal voltage of a Li-Ion battery is 3.7V. Fully charged is 4.2V which is the absolute maximum! It's considered empty at 3.2V. Li-Ion batteries are voltage charged, which means the charger MUST switch off at 4.2V. NiCd-batteries are current charged, which means they push a certain amount of current into the battery (typically at a much higher voltage) and must stop after a given time.

Last edited by Deniil715 on 20-Sep-2016 at 08:42 AM.

_________________
- Don't get fooled by my avatar, I'm not like that (anymore, mostly... maybe only sometimes)
> Amiga Classic and OS4 developer for OnyxSoft.

@Deniil715

Thanks for hte answer. I have always been thorough not to overcharge batteries but modern phone chargers, for example, stop charging when the battery reaches 100%, right?

I always charge my batteries to 100% too, maybe I should stop doing that?

@Niolator

Quote:

Thanks for hte answer. I have always been thorough not to overcharge batteries but modern phone chargers, for example, stop charging when the battery reaches 100%, right? I always charge my batteries to 100% too, maybe I should stop doing that?

All modern Li-Ion charges (like phone/laptop/etc) stop at 100% (4.2V) yes. typically the phone gets outdated before the battery dies, unless you mistreat it badly, like always having it plugged in.

Good laptop chargers are supposed to stop charging completely after being plugged in for some time after 100% and let the battery drop to like 90-95% before charging again. Phone chargers doesn't do that, so better unplug when reaching 100% (or even a little before ).

Of course, if you charge your phone only between 40-80% you only get 40% capacity to play with, so may only last half a day until it is down to 40% again :)

I think charging maintenance is most important in electric cars because the pull so much current from the batteries in a short time. Like 20 hour charging - 2 hour drive. With a phone it is the other way around: 2 hour charging - 20 hours play.

_________________
- Don't get fooled by my avatar, I'm not like that (anymore, mostly... maybe only sometimes)
> Amiga Classic and OS4 developer for OnyxSoft.

@Deniil715

My phones battery went bad after one and a half years. But that could have been because the phone fell out of my pocket when I biked 30+ km/h. I had to replace it. Now the phone pulls 25% in an hour when using the 3,5 mm plug. I will buy a new phone soon...

Clarification: It was the battery I had to replace.

@Niolator

Yeah, lots of things can fail in a phone ;)

But 25% in an hour, then it must get hot!

I just got a new phone. Moto G4+ I'll try to keep the battery between 20-95% or something and minimize the overnight charging. See how long it lasts. But then again, I've never killed any battery since I usually always let it cycled completely. No small charging, especially not when it's over 75%, few overnight charges.

_________________
- Don't get fooled by my avatar, I'm not like that (anymore, mostly... maybe only sometimes)
> Amiga Classic and OS4 developer for OnyxSoft.

@Deniil715

Two things kill Li-Ion cells: High temperature and high voltage.
In a laptop this is especially bad for those of us with docking stations. I had never used the battery in my laptop due to having a docking station and not travelling, battery was almost worn out by the time I needed it.

Now I have new battery, still forget to remove it when using docking. Even if I seldom use the battery. Man. Why am I so reckless?

edit: obviously full discharge also kills the cells, but noone ever does that because the cells are NOT TO BE USED WITHOUT PROTECTION AGAINST THIS. However, at full charge voltage, the cells will start growing crystals that don't hold any charge. And unfortunately, the voltage that causes damage is below the charging voltage. So if the charger isn't smart enough to completely cut at full charge, remove batteries from charger.

Last edited by olegil on 21-Sep-2016 at 08:53 AM.

_________________
This weeks pet peeve:
Using "voltage" instead of "potential", which leads to inventing new words like "amperage" instead of "current" (I, measured in A) or possible "charge" (amperehours, Ah or Coulomb, C). Sometimes I don't even know what people mean.

@Deniil715

No, it doesn't get hot. I don't know where the power goes.

@olegil

Yea, docking stations are bad. But I've figured out what kills a laptop battery the fastest: Having a laptop always plugged into a socket that doesn't always have power (connected to a lamp/wall switch), or where you move the laptop and its charger around. That way it restarts charging everyday, even if it's already full.

My laptop at work has a docking station but battary status is currently 95% (plugged in, not charging). It stops charging completely and let the battery drop several percent over a few days until it charges again. Of course, it requires continuous power. Can't be plugged in and out all the time without actual discharge. I take it home occasionally and then always run it on battery until it complains before plugging it in again. Unfortunately the docking station can't run on the laptop's battery otherwise I could cycle it while docked.

_________________
- Don't get fooled by my avatar, I'm not like that (anymore, mostly... maybe only sometimes)
> Amiga Classic and OS4 developer for OnyxSoft.