Originally Posted by VulcanRidr

After several weeks of using (and loving!) my N810, I have a question regarding the battery.

I used to have a Zaurus, and I found that I needed a battery every year or so. With the N810, the battery life is amazing relatively to my Zaurus. A the end of the day, if I am using the gps, I am at between 33 and 50% battery remaning. If I don't GPS, I am usually between 50 and 75% battery. When I go to bed, I plug the N810 in to power.

My concern is whether this is good for the device. I don't know what the actual charging cycle is, but when I got it, it charged in < 2 hrs. I have been plugging it in when I go to bed, and letting it charge all night. I am concerned that I am overcharging it that way. But I am concerned about being sans charge, and you can't take a snort off of USB.

What do you old Nokia heads do about charging? Is it bad to charge overnight?

Thanks,
--vr

Originally Posted by Karel Jansens

Lithium-Ion and Lithium-Polymer batteries actually like being charged often. Deep discharges do them more harm than frequent partial charges, so you're not doing anything wrong in that respect.

Leaving the charger plugged in doesn't do the battery any immediate harm either: LiIon and LiPol batteries have rather sophisticated charging circuits built into them, to prevent overcharging, and the tablet has its own overcharging protection. If you were to leave the tablet plugged in for weeks on end, eventually something might go wrong (although the odds of a lightning surcharge are probably higher than the circuitry going haywire on its own), but your charging habits are perfectly okay.

That said, LiIon and LiPol batteries have one drawback: They "age" on their own. From the moment it has been manufactured, a lithium battery starts to deteriorate and there's pretty much nothing you can do to stop that. Not using it will prolong its life (if you store it in a fridge, charged as close as you can get to 40%), but you have to agree the pointlessness of that strategy.

Every charging cycle also shortens the battery's lifetime; originally, lithium batteries would last only 100 to 150 complete charging cycles, but they're now up to 300 cycles and more, with some users reporting 500 charging cycles. For simplicifcation you can add up partial charges (i.e. if you recharge your battery always at 50% depletion, it could last 600 charges or more); it's not exactly that, but close enough.

So no matter what you do, depending on your use you still might have to buy a new battery every year. And, given what I wrote above, buying "spare" LiIon or LiPol batteries is not a good strategy -- as the spares will deteriorate -- unless you really need the extra battery regularly. For me, I found it better to invest in an external charger that takes AA batteries for the times when I need extra runtime. I have a 4 AA charger that will almost completely recharge the tablet's battery from 2500 mAh NiMh rechargeables.

Originally Posted by Karel Jansens

LiIon and LiPol batteries have rather sophisticated charging circuits built into them, to prevent overcharging, and the tablet has its own overcharging protection.

Originally Posted by Dragoon

many cell phone batteries are also lithium ion but they shouldn't be charged all night long. is there a difference there?

Originally Posted by Dragoon

many cell phone batteries are also lithium ion but they shouldn't be charged all night long. is there a difference there?

Originally Posted by Karel Jansens

It's the manufacturer/seller/salesdroid covering their collective butt. The only commercially available LiIon batteries that I know of that come without the charging circuitry, are those for R/C hobbyists (model cars, planes and that stuff), mainly because they have specialized ultra-fast chargers and, also, know what they're doing (overcharging an unprotected LiIon is a recepy for explosion).