Battery life

[vrocko]

Hey all,
How long can you use your Sylvania tablet without a charge? I can usually get about 3.5 or 4 hrs, depending on what I'm doing. Is this normal for these tablets?

Rich

[Sponsors]

[Rrok007]

Yeah, about that.

[lorenii]

it is VERY important to fully discharge the battery to auto shut off several times and fully charge to 100% each time. Your battery life may improve, but most importantly it will not get a 'memory' and start getting shorter and shorter. I never plug mine in unless it is below 20% or if I am going somewhere and I need 100% because there is no plug in where I am going.

[hecate]

Thought I'd add some info I just got from a Digital Gadgets rep (take their advice with a grain of salt ) that might be interesting. He said NOT to leave the tablet plugged in long after it's 100% (which I'd been doing, leaving it plugged while home and unplugging to go out so as to assure a full charge when I leave). He said (sounds weird, but he swears they've had quite a few reports of this) that the battery can "swell" when left plugged in and be ruined, something I never knew. So for now, I'm letting it run down to about 20% and not plugging it in until either late the night before or early the morning of me needing to take it with me, so it's full but not "overfull". Does that make sense to the folks here?

I usually also get about 3.5 hours of use before it's pretty much empty; I keep the screen brightness low; installing the Power Control Widget made it easy to control the brightness and the wi-fi with a touch.

[lorenii]

Makes perfect sense. I have also heard from my buddy at DG that the batteries will swell when overheated (over charged or charged while left ON). I had forgot about that...

[john_tartar]

That's pretty slipshod design. Most L-ion battery changers turn them selves off once the battery is fully charged.
My battery is down to about 20 minutes of capacity. Though I used to leave it plugged in all the time when not in use, but turned off, sometimes several days.
I just assumed that they were not idiots and would stop charging once it was full.

[vrocko]

Wow! Thanks all. There's a couple of new things I didn't know. Yeah when it comes to charging the battery I figured it would shut off when it was fully charged but it doesn't tell you when it's charged unless you plug it in while using it so you have no idea when it's charged. I'll have to watch when I plug it in to recharge it at night so I don't overcharge it. I usually use mine till the battery power is down to about 15% or 10%, it tells me when I'm low. I'll have to make sure I do that every time to improve battery life. I've done everything else I know of to save battery life, turn the brightness down, shut off/remove unnecessary apps, turn off wifi if I don't need it, etc.. I downloaded a battery life extender app and it helps out a lot. Gotta watch what settings I use on it cause it can cause issues. Any help you give is GREATLY appreciated. I like this little tablet but wonder about the more expensive ones. I suppose that if I saved money and waited to purchase a more expensive one instead of buying and trying a couple of cheaper ones I would be better off but hey then I wouldn't have met all the nice people on Androidtablets.net! Besides it's fun to play with this one and do what I want and I don't have to worry about Apple breathing down my neck because I "altered" their product.

Rich

[J515OP]

Hi guys, I can't help but comment on some pretty off base points in this thread to help keep myths from spreading.

1. You should NOT fully discharge the battery as this will degrade the life cycle of a Lithium-ion battery (the type of battery used in 99.9% of electronics these days).

2. The life of a Lithium-ion battery is actually rated by the number of charge cycles.

3. Recharging frequently and running the battery down less can actually increase the number of charge cycles in the battery's life.

4. As john-tartar said, that would be a pretty slipshod design if the device is made in a way that the battery swells when on the charger at 100%. Lithium-ion battery cells have protection circuits built in that limit the voltage on each cell and also monitor temperatures to prevent over charging or runaway discharging. It is possible this is an area that is poorly designed/monitored on the Sylvania tablets and not optimal for battery life. However if it was a serious issue there would be a recall due to the potential of the batteries overheating and catching on fire.

Here are a couple of quotes regarding Lithium-ion batteries with more information available at the source below. I hope it clears up some of the battery properties for modern Lithium-ion batteries.

"Lithium-ion is a low maintenance battery, an advantage that most other chemistries cannot claim. There is no memory and no scheduled cycling is required to prolong the battery's life."

"Despite its overall advantages, lithium-ion has its drawbacks. It is fragile and requires a protection circuit to maintain safe operation. Built into each pack, the protection circuit limits the peak voltage of each cell during charge and prevents the cell voltage from dropping too low on discharge. In addition, the cell temperature is monitored to prevent temperature extremes. The maximum charge and discharge current on most packs are is limited to between 1C and 2C. With these precautions in place, the possibility of metallic lithium plating occurring due to overcharge is virtually eliminated."

"Similar to a mechanical device that wears out faster with heavy use, so also does the depth of discharge (DoD) determine the cycle count. The smaller the depth of discharge, the longer the battery will last. If at all possible, avoid frequent full discharges and charge more often between uses. If full discharges cannot be avoided, try utilizing a larger battery. Partial discharge on Li-ion is fine; there is no memory and the battery does not need periodic full discharge cycles other than to calibrate the fuel gauge on a smart battery."

Overview of Lithium-ion batteries

Details about how Lithium-ion battery life is rated by cycles and how to increase the amount of charge cycles by charging frequently: How to Prolong Lithium-based Batteries


JP

[vrocko]

JP,
Thanks for your comments! Wow lot of info to take in. Thanks for the links too. Ok here's a question, if the battery eventually dies on you, ie has run it's course and can't hold a charge anymore, what do you do? I know for laptops you can buy a new battery but for Tablets like this and others is it a matter of tossing out the old Tablet and get a new one or can the battery be replaced? I fear the latter is a no go and a new tablet the only option but I'd like to hear from others. I've not had my battery get real warm on my Tablet to the point of being hot to the touch and I've not seen swelling of the battery but now that we speak of it is that really a possibility? Like you said JP, if it happened they would have to do a recall, similar to the recent recall of the Volt from GM, but could this happen on this tablet? I know I've had a few phones get pretty hot when used extensively but none of the batteries swelled or caught on fire. Let me know what you think. I will research this as well. Thanks again!

Rich

[J515OP]

Rich, it is certainly a possibility regarding the batteries. Unfortunately there are some quality control issues when it comes to Li-ion batteries. They can happen to any device at anytime depending on the battery that was used. Apple just issued a recall on their 1st (2nd?) generation iPod Nano years after the fact so you never know but the chances are still pretty small.

The reality of the world we live in today is that tablets are disposable devices. At the current pace, tablets have a life span of months considering the price to performance ratio we are seeing. So yes, in a couple of years when your tablet battery no longer holds a charge your only real option will be to dispose of it. By then we will all have cyborg implants though so you won't really miss it

JP