Is it ok to charge overnight?

[Rigmaster]

If you are asking if it will OVERCHARGE the phone, no it wont. The phone will shut off the charging once it gets full. As others have posted, we are not sure if the phone trickle charges after it is full, or if it just stops completely.

I've watched it during the charging process while it's sitting next to me at my computer. I don't believe it trickle charges because after it reaches full charge and stops indicating charging by the blinking charge indicator, it never returns to the blinking charge indicator. That indicator works regardless of whether full charge at 1000mah or lower-power charge (usb or charger) at 500mah. Anything that charges under 400mah isn't getting enough charge to the phone to charge while the phone is on.

Evo has been tested to use about 350-370mah while on typical but not heavy use (radio signal on, location services on, normal surfing/texting/phone use). That would line up with the approximate 5-6 hours of regular use people report. Less so for high-demand/heavy use like streaming video and GPS Nav. It uses about 200mah while on but not being used leading to the full day results that many report. And it drops to around 100mah when on but in Airplane mode and not used.

Not sure how people are reporting 60+ hours of battery unless they have almost all settings and radios off and brightness and other screen-related items down to bare minimums.

 

[theintoxicatedmofo]

i normally get 12-14 hours of use out of the evo on a typical day..one day i barely used the device and after 26 hours it was at 18% before i plugged it in. One thing that remains a mystery to me is that why the battery drops significantly after reaching max capacity..if you shut off the phone and charge it over night that way, if you power the phone on it will be at 100 but then dramatically drop 10% within the first 15 mins to at least 89...and that is with the phone off..with the phone on the same thing occurs which is why i just been unplugging when awake and then turning on all radios and max brightness so the battery counter can quickly become accurate..then i plug it back in and wait 15 min till it becomes full again

 

[gezzuzz]

come on.. you think this is 1972?.. recharagable batterys dont have issue like this anymore... all batterys wear out over time.. are you expecting to make this phone last more then 1-2 years? seems for some a $200 phone is alot of money.. maybe they should of got a boost phone or something..

 

[laredo7mm]

I've watched it during the charging process while it's sitting next to me at my computer. I don't believe it trickle charges because after it reaches full charge and stops indicating charging by the blinking charge indicator, it never returns to the blinking charge indicator. That indicator works regardless of whether full charge at 1000mah or lower-power charge (usb or charger) at 500mah. Anything that charges under 400mah isn't getting enough charge to the phone to charge while the phone is on.

Evo has been tested to use about 350-370mah while on typical but not heavy use (radio signal on, location services on, normal surfing/texting/phone use). That would line up with the approximate 5-6 hours of regular use people report. Less so for high-demand/heavy use like streaming video and GPS Nav. It uses about 200mah while on but not being used leading to the full day results that many report. And it drops to around 100mah when on but in Airplane mode and not used.

Not sure how people are reporting 60+ hours of battery unless they have almost all settings and radios off and brightness and other screen-related items down to bare minimums.

Good explanation, but just a bit of clarification to avoid confusion...

A phone charger does not charge with mah. It is ma, or milliamps. mah is milliamp hours, or capacity.

Same with the phone use. It does not use 350-370mah, it would be ma.

Batteries are rated with mah, but how they test for the mah is why some 3000mah batteries only perform as 1500mah batteries. If you drain the battery with a smaller load it will have a higher perceived mah.

 

[meyerweb]

The posts that suggest leaving the charger plugged in result in lower battery levels than if you unplug it when it's full make no logical sense at all. Think about it:

The claim is that once the battery reaches 100% the charging circuitry stops charging, and the phone runs off the battery.

What happens if you unplug the charger when the battery reaches 100%? That's right, the phone runs off the battery!

At worst, no difference at all. So know, you won't hurt anything by leaving the phone plugged in all night.

 

[Rigmaster]

Good explanation, but just a bit of clarification to avoid confusion...

A phone charger does not charge with mah. It is ma, or milliamps. mah is milliamp hours, or capacity.

Same with the phone use. It does not use 350-370mah, it would be ma.

Batteries are rated with mah, but how they test for the mah is why some 3000mah batteries only perform as 1500mah batteries. If you drain the battery with a smaller load it will have a higher perceived mah.

Correct. Charging output is ma only. The devices themselves limit how much they can take in or use.

Thanks for adding the clarification. I'm just trying to help people understand the battery issue in a more factual way. Anything that helps is appreciated.

 

[meyerweb]

i normally get 12-14 hours of use out of the evo on a typical day..one day i barely used the device and after 26 hours it was at 18% before i plugged it in. One thing that remains a mystery to me is that why the battery drops significantly after reaching max capacity..if you shut off the phone and charge it over night that way, if you power the phone on it will be at 100 but then dramatically drop 10% within the first 15 mins to at least 89...and that is with the phone off..

There are two things going on here, I suspect. One is that the charger doesn't really get the battery to 100%. This is an effort to make the battery lifetime longer. (Not how long it lasts each day, but the total number of months or years the battery lasts.) LI batteries do not like being brought to full charge or full discharge. Cars like the Chevy Volt, which uses LI batteries, keep the charge level between 25% and 75% for just this reason. The batteries are NEVER allowed to get anywhere near full charge. Now then, the Evo battery doesn't cost $15,000, so it's not as big a deal, but it will still last longer if it's not brought to full charge.

Given that you can get replacement batteries for $5 to $10 each, I'm not sure this was a wise tradeoff, but it seems to be what htc did.

The other thing going on is that if your phone is off, and you power it up, the very first thing it has to do is find towers, connect, and sync email, calendar, facebook, twitter, voice mail, etc. Ditto for WiFi, BT and GPS if you have those on. All that uses a whole lot of power right away. Not surprising to me.

 

[Rigmaster]

There are two things going on here, I suspect. One is that the charger doesn't really get the battery to 100%. This is an effort to make the battery lifetime longer. (Not how long it lasts each day, but the total number of months or years the battery lasts.) LI batteries do not like being brought to full charge or full discharge. Cars like the Chevy Volt, which uses LI batteries, keep the charge level between 25% and 75% for just this reason. The batteries are NEVER allowed to get anywhere near full charge. Now then, the Evo battery doesn't cost $15,000, so it's not as big a deal, but it will still last longer if it's not brought to full charge.

Given that you can get replacement batteries for $5 to $10 each, I'm not sure this was a wise tradeoff, but it seems to be what htc did.

The other thing going on is that if your phone is off, and you power it up, the very first thing it has to do is find towers, connect, and sync email, calendar, facebook, twitter, voice mail, etc. Ditto for WiFi, BT and GPS if you have those on. All that uses a whole lot of power right away. Not surprising to me.

The battery does reach 100% charge. It just does not resume charging until a command (unplug, power off, or something like that) forces charging to begin again. The Evo software is causing this problem.

The boot commands and connections take a surge in power, but it should never be enough to take even 1% of a full charge.

I've been unplugged since 7:30am this morning and am currently at 90% with wifi connected but updates and refreshes only done every 4 hours - but no facebook, email, or other running services on unless I change them. I'll go to full 3G, texting, and calls from 4-7pm, almost continuous wifi-surfing from 8-10:30pm, and then back to wifi but no connections status overnight. I get down to 15-20% just before going to sleep every night.

I look forward to Froyo so the way the phone sorts info is more efficient, and an update from HTC addressing the recharging limitation.

 

[NinjaStar28]

Yes it does. The speed with wich it goes from 100% to 95% is a matter of minutes with no use. It doesn't slow down until the high 80s. What I do is, charge it at night, when I wake up I unplug it and I start get ready for my day. After about 5 mins, I plug it back it and it takes 15mins to reach 100%. I unplug it and I'm set. It will stay at 100% for quite a while after that.

i dont think un plugging ur batt in and out b4 a complete charge every day is good for the batt life ?

 

[stainlessray]

The posts that suggest leaving the charger plugged in result in lower battery levels than if you unplug it when it's full make no logical sense at all. Think about it:

The claim is that once the battery reaches 100% the charging circuitry stops charging, and the phone runs off the battery.

What happens if you unplug the charger when the battery reaches 100%? That's right, the phone runs off the battery!

At worst, no difference at all. So know, you won't hurt anything by leaving the phone plugged in all night.

the way i understand it, thats the perception of whats happening. when in fact it's the phone reading the actual remaining charge more and more accurately over the first 15 minutes or so. caused by the fact that it stops charging when the phone perceives it as being full, and running off the battery. it reflects charge reading, not the discharge happening at an accelerated rate, that would be illogical. (whereas a phone having a glitch like this is just DUMB, but perfectly logical.)

 

[NinjaStar28]

No you cannot overcharge your battery or cause damage to it by charging overnight. Today's lithium ion and lithium polymer batteries cannot be overcharged. They still degrade with use over time like all other batteries, but recharge cycles are typically in the 1000-2000 range. I think the Evo battery is rated for 1000 charges.

What will damage batteries LI batteries most is overheating.

What causes the inconsistency in battery charge and battery charge levels is the actual phone itself. While today's batteries don't have built-in recharge meters like older rechargeables, the phones still have charge meters that control everything related to the battery, including charging and power draw. The interaction is similar to how gas station pumps now work. They are pressure sensitive so that they automatically stop when the tank is "full enough." That's why they can always be topped off with short bursts of fuel even after they automatically shut off. The phone works the same way, when it's full it begins limiting charge. The reason you see an immediate drop is that it stopped charging while you were asleep and doesn't resume full charging unless unplugged and replugged.

People believe batteries can be overcharged, but overcharge would actually result in overheating, expansion, then leakage from the battery. That doesn't happen any more because LI cells don't work the same as old battery cells.

Wow that is great to know and it makes perfect sense ..... u should leave n email so we can contact u straight with questions u know ur stuff !

 

[NinjaStar28]

i normally get 12-14 hours of use out of the evo on a typical day..one day i barely used the device and after 26 hours it was at 18% before i plugged it in. One thing that remains a mystery to me is that why the battery drops significantly after reaching max capacity..if you shut off the phone and charge it over night that way, if you power the phone on it will be at 100 but then dramatically drop 10% within the first 15 mins to at least 89...and that is with the phone off..with the phone on the same thing occurs which is why i just been unplugging when awake and then turning on all radios and max brightness so the battery counter can quickly become accurate..then i plug it back in and wait 15 min till it becomes full again

READ the comment from RIGMASTER skroll up and read the perfect reason y the batt does that

 

[Rigmaster]

Wow that is great to know and it makes perfect sense ..... u should leave n email so we can contact u straight with questions u know ur stuff !

Just PM or post here. I usually check the site first thing in the morning, midday, and before I turn in for the night.

I've collected a vast amount of info, most of it useless, in my electronics hobby. But I'm willing to share whatever I can.

The whole battery issue is probably slightly overblown. Evo is a power phone, which also means a power-hungry phone. That said, just understanding how batteries work means I don't get disappointed by battery issues.

I always come back to this - try to do anything we're doing with this phone in comparison to a laptop, and the battery issue isn't an issue. When comparing to other phones, it has to be a like comparison which is very difficult to get. I also think Evo is helping some people understand that if they simply want great battery life, maybe a less powerful phone is the way to go for them.

I'm an Evo fan for what it does, not what it doesn't.