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Good to Drain Battery Purposely?

T

TheMightyEddy

Lurker
I have read online how to consume battery life on my HTC Vivid 4G running on Android. Though the last thing the article said to conserve battery life is to NOT drain the battery because phones these days use Lithium Ion or whatever so you should charge it whenever you need to; not drain it. Though I also have an iPad 2 and I read another article of how to conserve an iPad's battery life and it said you should drain your battery to around 10-20% left and then charge it because it's better for the battery or whatever.

So which step should I take? Should I drain the battery life to around when the battery icon gets red or should I just charge it whenever I need to charge it or whenever I think it needs to be charged? Thanks,
 
Lithium batteries don't like to be fully discharged, so it's best to charge before they get to zero. If drained completely, there is the chance it will stop accepting charge again, but in most cases, full discharges will just shorten the life of the battery if done on a regular basis.

I tend to charge my battery between 30%-40% if I can, but usually just charge when I feel like it.
 
Before lithium ion batteries were commonly used, the most common rechargeable batteries were nickel metal hydride batteries. These batteries need to be discharged completely before recharging to ensure they have a long battery life. Chargers for these batteries have a setting where the charger would first completely drain the battery before charging.

Nowadays, lithium ion batteries are the most common and they are more convenient because you do not need to fully discharge them before charging. They are rather like the opposite. Discharging them completely before recharging them will shorten the life of these batteries.
 
I charge my Li batteries whenever I feel like it because it does not hurt it. I have read that when the battery reporting level may lose accuracy over time (battery is good but the internal circuitry reporting the battery level loses calibration). When that happens, it is advisable to drain it down and recharge it fully before using (recalibrates the battery reporting level). And IIRC, all lithium batteries will age over time whether you use them or not. Therefore, it is not adviseable to buy a spare and just let it sit around. For the same reason, I prefer not to buy a spare and swap batteries in and out; over the same time period you will just end up with two tired batteries. Also, I find it more of a hassle to carry and swap out spares then just to recharge more often (of course, your usage may require that you have no access to charger and may need to carry multiple spares). IMO, it is better just to use just one battery until it wears out and then buy a new fresh one. All the info is in Battery University if you want to read it.
 
I travel quite a bit and always buy a spare battery and stand-alone charger for any new phone I get. I typically keep my phone for 2-1/2 to 3 years and have not noticed any degradation in charging capacity for my primary or spare battery. Usually I get a full day out of a battery so I just swap it in the morning for the fully charged alternate. When I'm travelling though it is very convenient to be able to skip a charging day if necessary.
 
NEVER completely discharge a Li-Ion battery. The "low charge" warning given by the OS, and the auto-shutdown at ~2%, are there for a reason. If it's drained to zero then there's a very good chance that the battery's own internal safety circuits stop functioning and prevent it recharging.
 
I have been wondering about this, so I am glad this thread was opened. From reading it I have gleaned that it won't hurt to charge the new phone batteries "whenever," HOWEVER, I would remind you all that all batteries do have "x" amount of charging cycles before they are shot, so it's all the same to the battery if you charge it from 60% as from 10% it still counts as one full cycle. Having said this I'd like to ask what is the OPTIMUM percentage to charge without worrying about going too low and harming the battery. Would between 15-20% be about right?
 
hiredgun said:
HOWEVER, I would remind you all that all batteries do have "x" amount of charging cycles before they are shot, so it's all the same to the battery if you charge it from 60% as from 10% it still counts as one full cycle.
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No, it's not that simple. If any charge - long or short, any capacity - was equal to any other then leaving it on charge permanently would mean it would last forever - one charge, right? ;-)

With lithium batteries common sense rules; forget all the advice about other battery technologies, it's both irrelevant and can be quite harmful. Instead charge the battery whenever to keep it more or less charged without allowing it to overcharge (the heat is harmful) nor allow it to discharge too deeply which may cause permanent damage.

As I said, common sense works best for lithiums :-)
 
John Bean said:
No, it's not that simple. If any charge - long or short, any capacity - was equal to any other then leaving it on charge permanently would mean it would last forever - one charge, right? ;-)

With lithium batteries common sense rules; forget all the advice about other battery technologies, it's both irrelevant and can be quite harmful. Instead charge the battery whenever to keep it more or less charged without allowing it to overcharge (the heat is harmful) nor allow it to discharge too deeply which may cause permanent damage.

As I said, common sense works best for lithiums :-)
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I'm not saying that you are wrong John, but I'd like you to explain to me exactly why I am wrong. It isn't true that every battery has "x" amount of charge cycles??
 
hiredgun said:
I'm not saying that you are wrong John, but I'd like you to explain to me exactly why I am wrong. It isn't true that every battery has "x" amount of charge cycles??
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Kind of yes, and kind of no.

A Lithium battery will lose charge over time (to the point that it won't charge any more), but there's no set amount of charge/discharge cycles.

Charging Lithium-Ion Batteries – Battery University

Frequetly Asked Questions on How to Charge Batteries

Have a read through those links for a bit more info.
 
The way I've read it in the past, yeah a li-ion has X amount of cycles but two half cycles= one cycle, ten 10% cycles= one cycle etc.
In my experience though you can throw anything at these batteries and they're fine for the average life of a phone :thumbup:
 
funkylogik said:
The way I've read it in the past, yeah a li-ion has X amount of cycles but two half cycles= one cycle, ten 10% cycles= one cycle etc.
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That's one way to look at it but it really doesn't need any numbers. "Little and often, everything in moderation" sums up the best practice for charging Li-ion, almost exactly the opposite of that for most other battery types. Just try to avoid extremes of anything - charge level, temperature, whatever - and they last a long time, usually exceeding the life span of the device being powered.
 
Just for the record I WANT you guys to be right, lol. I am so meticulous about charging the batteries, making sure it gets low enough and not charging it when it's still got a high percentage left!! It would be just great to charge the darn things when ever I want too, lol
 
Not charging it when it's nearly full is a good rule. Getting it low enough? Nope, don't bother about that. I just ask "will it last me through tomorrow?" and charge it if not.
 
1. I carry the phone all day and keep an eye on the charge level.
2. If it dips below abut 75% I back off; disable data and such.
3. If it dips below 50% -- very rarely -- I turn it off unless I really need it.
4. In the evening, I plug it in, do its updates, leave it charging overnight.

Been doing that for several years just like, paying almost no attention.
 
hiredgun said:
Just for the record I WANT you guys to be right, lol. I am so meticulous about charging the batteries, making sure it gets low enough and not charging it when it's still got a high percentage left!!
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Avoid charging if it is more or less fully charged already is common sense and good for the battery, but letting it get "low enough" is bad as it risks letting it get too low which can do real harm.

It would be just great to charge the darn things when ever I want too
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Don't waste time worrying about it. Use common sense and charge it when it needs charging and it will be fine.
 
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