Is it better to charge your phone to full, then let it drain to empty before recharging it again?
Or does it really matter if you charge it before it’s empty?
And on the extreme end, is it actually harmful to the battery to leave it charging unless it’s in use?
Poll to follow.
MrTao insists I’m damaging or destroying cell phone batteries by charging them up as soon as they’re not full. I leave them charged overnight, and often leave them charged in if I’m not using the phone and it’s not full. This is only my phone we’re talking about, not anybody else’s. He charges his overnight, every night, whether it needs it or not; I’ve never noticed that he lets HIS go totally dead before charging it, but maybe it drains completely during the day, who knows.
I maintain that it hasn’t made a difference either way, I replace a battery about once a year, so what’s the harm?
Your opinion?
I charge mine while I sleep.
Charge when it gets to half full. For mine, that’s several days.
Not with lithium based batteries, no. Running a lithium battery to very low capacity on a regular basis will actually stress it and result in a shorter useful lifespan.
It’s preferable to recharge before you dip below 20-30% capacity and not harmful to recharge at any capacity less than full.
Yes. Leaving a full capacity battery on a charger for extended periods of time is also stressful and will also result in a shorter useful lifespan.
Full cycle recharging was preferable in the days of nickel cadmium (NiCad). LiIon and LiPo batteries (which is what you’ll find in almost every mobile phone) actually suffer from full cycle charging. The truth is, batteries are pretty resistant to abuse but anyone telling you that “you’re doing it wrong” if you’re not running your lithium battery down to near zero capacity is worse than wrong. They’re actually advocating a practice that’s destructive to the battery.
Thank you, Jake! I won’t leave it charging all the time, but I’ll continue charging it to full even if it’s only half-empty. The info is much appreciated 
With smartphone battery life barely making a day, I don’t have much choice as to when I charge. I need to leave the house with a full battery. So I bought an extended warranty, and if anything goes wrong it’s up to the manufacturer to fix it.
I charge mine overnight, or when the battery gets to the red zone.
Overnight, usually.
My phone almost never leaves my car. If I go a week without driving, it’s usually pretty close to dead from just sitting there, and it’ll charge when I do drive.
If it matters, it’s a cheapie non-smart very basic phone - I have it in case I have problems when I’m driving somewhere. Otherwise, I’d get rid of it. I use it so rarely, I honestly have no idea what its battery life is.
I have three batteries that I rotate on the wall charger I bought so I always have one charging, one charged and ready and one in the phone. That way if I am out and the battery starts to go I can pull the spare out of my purse and pop it right in.
Exactly what I’d do in a perfect world. Instead, I charge while driving, keep a charger at work, and another at home.
I’ve had my current smartphone 2 years, and the battery shows signs of deterioration.
The only time this matters is when the phone is brand new. Drain it completely and charge it fully the first 3 times.
I just got a new battery for my Galaxy S2 because the original one was swollen from overcharging, but I usually keep a battery for a year, so hopefully this lasts til my upgrade. This battery seems to be waning already and I’ll have to stay on top of it more. I tend to charge at night or when it gets to 30%.
Mine has an indicator with three little lights (an icon of a battery in three sections, each of which can be on or off.) When any of the lights is off, I re-charge. So, I guess, if the indicators are linear to the power in the battery… Charge when it drops to 2/3 full.
Having a car adapter is also a really good idea; that saved my bacon once.
I’ve been through about 4 dumb phones now (Nokia and Samsung) and it didn’t make any difference when I charge them, I just plug them in every 4 or 5 days.
Yes a car charger is a good idea, be aware you can get a generic 12V to USB adapter so you can charge your phone via USB, rather than a specific 12V to phone adapter.
My understanding is that Li-ion chemistry basically means that the battery will eat itself over time. To forestall this about 40% charge level is best and shortens dramatically if you approach and hit 0%. Also, but to a lesser extent you shorten it as you approach 100%. Additionally manufactured impose artificial limits to improve expected life, but this reduces capacity.
My take on it is ideally recharge around 25%-35% up to 80%. When I use my car dock it sometimes works out like that, but practically I just dont consider recharging it till it gets below 40% unless I know I need it fully charged.
Any ideas why those first three times are important? I’ve always assumed that it’s already been tested by charging and recharging, before I get it, so…? Even if not…why are the first few times different? I’ve hear that a lot, but have no idea why.
It’s not important, really - to the battery, at least. Doing that is usually more for getting the phone’s battery capacity meter calibrated to the battery’s actual capacity.