• After 15+ years, we've made a big change: Android Forums is now Early Bird Club. Learn more here.

Extending the longevity of your battery

novox77

Leeeroy Jennnkinnns!
Jul 7, 2010
3,964
3,257
This thread is NOT about making your battery last longer between charges. There are plenty of those out there with tips on how to extend your battery's charge.

The purpose of this thread is to share with you some PROVEN tricks on how to extend the lifespan of your battery. Everyone knows that rechargeable batteries eventually lose their capacity to hold charge, and Li-Ion is no exception. However, there are things you can do to significantly slow down the aging of your battery. Again, these are proven (measurable) techniques, and they do not originate from the NiCd or NiMH days of charging.

1) Li-Ion is sensitive to hot temperatures. They can be instantaneously damaged by intense heat, and they can lose a lot of longevity though prolonged, minor heat. Unless absolutely necessary, try not to let the battery stay higher than 40 degrees Celcius for prolonged periods. The sweet spot for Li-ion temperature is between 20-35 degrees C. Don't ever leave your phone in the car on a hot day, or leave it in the sun. The high temps will damage the battery even if the phone isn't on.

2) Keeping the battery near full charge all the time strains the battery and decreases its longevity. In the case of the Evo, where battery drain is very rapid, this is pretty much a non-issue. But basically, keeping the battery near 100% all the time is no good. This is the main reason why laptop batteries die before the expected 2 years of life. Some people think this reduced life is because of the charger overcharging the battery, or that it's constantly doing short charges when the battery starts to lose a bit of charge. This is NOT the case. If your laptop is always plugged in, set your max battery charge to 50% and set it to charge when it trickles itself down to 25%.

3) It's not necessary to drain/discharge a Li-Ion before charging it. In fact, draining the battery could actually prevent your battery from ever charging again. It needs a certain amount of charge in order for it to be rechargeable. New batteries have a reserve charge that you can't tap into, so this is no longer harmful. But just know that you can charge your phone at any current charge level, and it's not harmful. There's no more "memory" issues like in the NiCd days. It's also not necessary to charge the battery all the way to 100%. The ideal charging practice is to charge briefly and frequently, and try to avoid charging to near max capacity. Might not be practical for the Evo, but certainly doable for a laptop.

There are other tricks, but none make more difference in longevity than keeping the battery between 20-35 degrees Celcius as much as possible, avoiding leaving the phone somewhere where it can get really hot, and keeping your average charge around 50%. If you stick to these guidelines, you can expect way more than 2 years out of your battery. I have gotten 7 years out of my laptop Li-Ion and it's still going strong. My blackberry battery from 2007 is still in top shape.
 
That is really helpful info man, question... I had read in another thread something about battery conditioning. The idea is that you turn off your phone and charge it until the "green" light comes on, then unplug the charger and wait for the light to go off. Next hook it back up and the "amber" light comes on, when it turns green again then unhook it again. They say to do this like 10 times and it will condition your battery to 100% effectiveness and allow it to last much longer.

What are your thoughts on this practice. Your post indicates 100% charging may not be such a good idea?
 
Upvote 0
That is really helpful info man, question... I had read in another thread something about battery conditioning. The idea is that you turn off your phone and charge it until the "green" light comes on, then unplug the charger and wait for the light to go off. Next hook it back up and the "amber" light comes on, when it turns green again then unhook it again. They say to do this like 10 times and it will condition your battery to 100% effectiveness and allow it to last much longer.

What are your thoughts on this practice. Your post indicates 100% charging may not be such a good idea?

There's no real harm to charging your battery to 100%. You just don't want the battery to ever sit around with a high charge. For the Evo, this is not an issue, since it tends to drain the battery fast. It's really a problem with laptops that are always at home/office on the desk. The laptop is always plugged in, so the battery charge is always maintained high. That strains the battery over time. With a mobile device, you're less likely to leave it plugged in (kinda defeats the purpose of having the "mobile" device).

As for the practice that you mentioned, I don't believe it has any basis, or the measureable improvement to battery longevity is so small that it's hardly worth the effort.

Forgot to mention: if you ever need to store the phone/battery, you want to drain it down to 35-50% and store it in a cool location, like room temp (25C / 70F).
 
Upvote 0
There's no real harm to charging your battery to 100%. You just don't want the battery to ever sit around with a high charge. For the Evo, this is not an issue, since it tends to drain the battery fast. It's really a problem with laptops that are always at home/office on the desk. The laptop is always plugged in, so the battery charge is always maintained high. That strains the battery over time. With a mobile device, you're less likely to leave it plugged in (kinda defeats the purpose of having the "mobile" device).

As for the practice that you mentioned, I don't believe it has any basis, or the measureable improvement to battery longevity is so small that it's hardly worth the effort.

Forgot to mention: if you ever need to store the phone/battery, you want to drain it down to 35-50% and store it in a cool location, like room temp (25C / 70F).

Could this be the reason the EVO appears to stop charging at 100% and many see a rapid drop to ~90% after unplugging the EVO? Perhaps HTC has designed it this way to prevent it from sitting at 100%?

Just a thought. Good info.
 
Upvote 0
Could this be the reason the EVO appears to stop charging at 100% and many see a rapid drop to ~90% after unplugging the EVO? Perhaps HTC has designed it this way to prevent it from sitting at 100%?

Just a thought. Good info.


Yeah, I think the charger is intentionally shut off after it detects full charge. It's likely for situations where you left the phone plugged in and went on vacation or something. You really wouldn't want the phone sitting at 100% that whole time.

OTOH, you wouldn't want to return home to a dead phone that's been plugged in the whole time, so I suspect that there's a lower threshold that will allow the charger to kick back in. That would be a very smart charging system.

Some people think it's a defect for the phone LED to show green, when in reality the battery has discharged to 90%. I think I can see where HTC was going with that. If the phone hit 100% and then dropped to 99%, and if the light goes amber again, you might think the phone still needs charging and leave it plugged in longer. The other solution would be to turn off the light, but then you might think the charger is defective :)
 
Upvote 0
My battery can get warm sometimes. I think the hottest it got was 116 degrees F. Lol

Yeah, that's pretty warm. BTW, I should have provided numbers in Fahrenheit as well. The sweet spot for Li-Ion batteries is 20 to 35 degrees Celcius. That is roughly 68 to 95 degrees Fahrenheit. Keep your battery in that range most of the time, and you'll be fine.
 
Upvote 0
Good advice. Also important to keep in mind that most devices and chargers turn excess charge into heat. Transformers on chargers get warm to the touch, but it's the built in protection mechanism for overheating. Phones usually don't have the requisite structure and surface area to dissipate the heat so the battery connection as a heat source in the phone could be amplified after it stops accepting charge.

I agree that HTC probably built in some of the charging mechanisms to prevent overcharging. HTC (and then Sprint) sort of hurt things by following that up with official advice that encouraged people to keep the battery topped off whenever possible.
 
Upvote 0
Thanks! Great advice here.
I'v been leaving my phone charged all the time whenever I'm home and it's always fully charged throughout the night when I'm sleeping. So you think it's better to just leave my phone uncharged throughout the night when I'm sleeping?
Also, I am always charging it whenever I play games on it, too. Would that be okay since it's using up battery?
 
Upvote 0
Thanks! Great advice here.
I'v been leaving my phone charged all the time whenever I'm home and it's always fully charged throughout the night when I'm sleeping. So you think it's better to just leave my phone uncharged throughout the night when I'm sleeping?
Also, I am always charging it whenever I play games on it, too. Would that be okay since it's using up battery?

If your battery can last the entire waking day through normal usage, I recommend just charging it overnight. It's useful to start your day with a pretty full battery.
 
Upvote 0

BEST TECH IN 2023

We've been tracking upcoming products and ranking the best tech since 2007. Thanks for trusting our opinion: we get rewarded through affiliate links that earn us a commission and we invite you to learn more about us.

Smartphones