[Silverfern]

How is battery life for the PB (and other tablets) tested? they say its go 7 hours, but mine last like over 15 hours with still 40% left with light/medium use (do some BBM, watch 2~3 hours of videos, listen to 3 hour or so of music), so just wondering where they got the 7 hours from

p.s. music is with headphones on, video is speakers at a bit over 50% volume

[AsBloodRunsBlack]

Its funny that you say that cuz I noticed with my PB I get about that much to. I use it alot in a day. And dont have to charge it for 2-3 days. I love it. My Android phone does not even last the long.

[esqlaw]

You get 15 hours of usage? My experience is about 10 hours of usage. I came to this conclusion because every time I do use it for an hour straight its about 10% off the power bar. Although recently I do have to say that the power usage appears to be better than previously so maybe I am now wrong.

I also have bluetooth and wireless on all the time. And the amount of RAM and processing power you use at any moment will substantially affect your power usage.

[Silverfern]

You get 15 hours of usage? My experience is about 10 hours of usage. I came to this conclusion because every time I do use it for an hour straight its about 10% off the power bar. Although recently I do have to say that the power usage appears to be better than previously so maybe I am now wrong.

I also have bluetooth and wireless on all the time. And the amount of RAM and processing power you use at any moment will substantially affect your power usage.

yes i have bluetooth on all the time for bridge, and also wifi. , i still have 31%, only used 6% since i posted this post blasting my speakers

[Silverfern]

ok, i found out how they test it, they run a video over and over until the battery dies

[AsBloodRunsBlack]

I always turn my bluetooth and wifi off when ever I am not using it. Maybe that is why I dont have to charge it so ofter. I do use wifi alot though.

[mithrazor]

Mines drops pretty quick when it's in use.

But on average, it'll last me a day and a half or two.

[Serkle K]

I've been wondering the same thing. I got my PB 4 days ago and I've used it for the last 3days while at work as well. I unplug it at around 6am, by the time i get home 12 hours later its down to about 40%. Again its only been 4 days but since this is new to me its also been under heavy usage to figure out all the bells and whistles as well as limitations. IMO, 40% remaining after 12 hours of usage with Bluetooth, Bridge, and WiFi on all day is pretty good! I was more concerned that my 9800 wouldn't be able to last as long, but then again i realized i have chargers everywhere (work, car, home).

[peter9477]

How is battery life for the PB (and other tablets) tested? they say its go 7 hours, but mine last like over 15 hours with still 40% left with light/medium use (do some BBM, watch 2~3 hours of videos, listen to 3 hour or so of music), so just wondering where they got the 7 hours from

p.s. music is with headphones on, video is speakers at a bit over 50% volume

The testing would be with the screen on that entire time. The screen (and backlight) uses by far most of the power, so if you're ever "using it" with the screen actually off, like to play music, you'll get way more than just the nominal 7-8h figure.

Also, if you happen to use it in fairly low light most of the time, and have the "auto-dim" setting enabled (which it is by default), you will get significantly more. We've heard from several people who managed over 10h of movie viewing on planes because of that.

[RicThot]

I usually use the PB from 7am to 10pm, then charge it. At the time I plug it in, battery reports around 30%. This is with WIFI on all the time, BT off, screen brightness set to around 35%. Pretty good as far as I'm concerned.

Screen has to be the biggest factor, I did see quite a difference only by decreasing the brightness from 75% or so down to 35/40%. Didn't do this to save power at first, I started to get headaches with the screen so bright in dim lights condition at home, then realized it made a nice difference on power consumption...

[kill_9]

I generally tend to let the battery drain to 0% before recharging unless I know I am going to be away from a charging dock and current battery charge is too low to make it through. The Battery Guru application comes in very handy for trend analysis. Being able to dim the screen definitely extends the life of the current charge; usually operates at 65% brightness.

[Silverfern]

I generally tend to let the battery drain to 0% before recharging unless I know I am going to be away from a charging dock and current battery charge is too low to make it through. The Battery Guru application comes in very handy for trend analysis. Being able to dim the screen definitely extends the life of the current charge; usually operates at 65% brightness.

isnt letting the battery drain to 0% bad for the battery? i heard it shortens to useable life of the battery

[FF22]

I still seem to lose about 10-13% overnight when I'm not using it. Wifi and BT remain on.

But my bb phone does to sleep at 11pm and awakes at 6am - wonder if the pb expends energy looking for the phone?

[peter9477]

isnt letting the battery drain to 0% bad for the battery? i heard it shortens to useable life of the battery

This claim is probably from incorrectly applying experience gained with older battery technologies to the Lithium-Ion batteries, which don't have that problem (or any memory).

There are two main concerns with Lithium, only one of which may apply to the PlayBook. One of these that high temperatures during charging will damage the battery. This is only going to happen with the PlayBook if something's defective, so I wouldn't even think about it. Normally the PlayBook will limit the charging current to entirely safe levels, even with the rapid charger, and the charging software monitors many things including the temperature of both cells, to ensure no damage will occur.

The only other thing that will damage a Lithium battery is if the level (as measured by voltage) drops below a lower threshold which is around 2.8 or maybe 3V. The PlayBook reports 0% around the time the battery reaches 3.4V, so there's a huge safety margin. The only way you could damage your battery is if you discharged it until it shut off by itself (around 3.4V) and then either repeatedly tried to turn the power on, forcing further discharge, or left it discharged in storage for many weeks or months.

(Lithium batteries apparently have no actual leakage of their own, but all of them have integrated protective circuitry which does create a very small drain (in the micro or even nano-amperes) and that will over a long time result in a detectable drain.)

Lithium batteries are shipped with approximately 40% charge to avoid any problems with this, and it would be very difficult to force this condition yourself if you ever actually use your PlayBook, so go ahead and discharge to 0% as often as you like, provided you recharge at least partially shortly after (i.e. within a week or two should be more than safe).

Discharging to 0% (of right to the point it shuts off) may have some small advantages if done from time to time as well: RIM suggests in one knowledge base article that it will assist the software in recalibrating the % indicator to be more accurate.