do phones stop charging when fully charged

[malabo]

am i ruining my battery if i leave it plugged in after its 100% charged. will i get battery distension and a ruined phone?

 

[Brian Stirling]

I doubt there's been a smartphone made in the last six years that didn't have smarts in the charging system. I charge my phones and devices at night -- I plug them in when I go to bed and unplug them when I get up in the morning and I've been doing this since 2009 when I got my first smartphone. If this were a problem I'd have had it by now.

Part of the design of a modern battery operated smart device is a charge controller who's job is to charge the battery but not overcharge it. Most phones have a single cell battery making the charge control much easier than a true battery with multiple cells.


Brian

 

[JeffMD]

Ahh this question again, from people who don't know how to search.

No, lithium batteries do not trickle charge. They will toggle the charge on and off in the top %5 (Not something observable). You won't kill the battery any faster.

 

[GTRagnarok]

Leaving it plugged in is not a problem. Some misinformed people still suggest unplugging when fully charged and using the battery to a low charge before plugging in again. Don't do that. Charging from a low state heats up the battery a lot. AFAIK, heat is the fastest way to kill a battery. A normal phone that's plugged in and fully charged should be completely cool to the touch if it's not being used.

 

[StrangerGuy]

Leaving it plugged in is not a problem. Some misinformed people still suggest unplugging when fully charged and using the battery to a low charge before plugging in again. Don't do that. Charging from a low state heats up the battery a lot. AFAIK, heat is the fastest way to kill a battery. A normal phone that's plugged in and fully charged should be completely cool to the touch if it's not being used.

It's amazing how people thinks their own baseless intuitions about batteries is more credible than the knowledge of the EEs who designed these things in the first place.

 

[JeffMD]

There are inherent dangers with heat, but normal charging temps alone are not enough to damage a battery. Charge whenever you want. The only danger is if a lithium battery for some reason allows you to completely drain it dead, it may not charge again.

 

[shabby]

The only danger is if a lithium battery for some reason allows you to completely drain it dead, it may not charge again.

Where did this myth come from?

 

[JeffMD]

Shabby, it came from peoples whos devices discharged and would no longer charge again. It is not a %100 thing, and I "could" say the reason the battery died and would no longer take a charge is BECAUSE the battery is damaged and will no longer take a charge, but either way it should be avoided if not for the sake running out of power when you actually need to use it.

 

[lxskllr]

Shabby, it came from peoples whos devices discharged and would no longer charge again. It is not a %100 thing, and I "could" say the reason the battery died and would no longer take a charge is BECAUSE the battery is damaged and will no longer take a charge, but either way it should be avoided if not for the sake running out of power when you actually need to use it.

Zero isn't zero on a device. They /try/ to stop before damage occcurs, but batteries definitely can't be drawn all the way down. In any case, I haven't used a battery yet that likes being deep cycled. Some are more /tolerant/, but it's best not to do it with any of them.

 

[blankslate]

not sure if if changed but before the depth of discharge or how low the battery charge was allowed to go before recharging them could impact the amount of charge cycles as well.

Such that charging from 50% when possible (for example) could result in more overall life from the battery overall than letting it discharge almost fully before recharging.

Personally I'm hoping that the initial research into batteries at Singapore's University pans out.

http://media.ntu.edu.sg/NewsReleases/Pages/newsdetail.aspx?news=809fbb2f-95f0-4995-b5c0-10ae4c50c934

Scientists at Nanyang Technology University (NTU) have developed ultra-fast charging batteries that can be recharged up to 70 per cent in only two minutes.

The new generation batteries also have a long lifespan of over 20 years, more than 10 times compared to existing lithium-ion batteries.

This breakthrough has a wide-ranging impact on all industries, especially for electric vehicles, where consumers are put off by the long recharge times and its limited battery life.

Something like that would make user replaceable batteries in phones less of a hard requirement for me (although still a preference that could influence my choice of phone).

It is worrying however, that I haven't heard anything else about these batteries. Maybe the hit a snag that stopped development necessary to bring the technology to the average consumer.


________________

 

[sweenish]

It's amazing how people thinks their own baseless intuitions about batteries is more credible than the knowledge of the EEs who designed these things in the first place.

It's not baseless intuition, it's a history with NiCd batteries that they assume translates.

They assume wrong, but it's not baseless.

 

[JeffMD]

Ixs , considering the charging ic in devices are not part of the premium chipset, I would not be surprised if they were cheap productions even on the highest end devices. Even flag ship phones are laden with things like basic audio chips. Not everything is premium.

 

[danu4u]

The mobiles of previous generation had that problem. That's why some batteries used to blast because of excessive charging. But not now!