So my battery for N810 just [from a usability-perspective] bit the dust. It technically still works if rebooting every 2-8 minutes counts; I may try charging it with my external charger and see if that helps it any.

So, I stole the battery from my other N810.

But of course I would like both up and running and the spare cheap knock-off battery I have doesn't have a decent capacity.

On ebay, there are two distinct price-points, $5-10 for a "genuine"/blatant knock-off and $30 for a "genuine"(?)/sitting-on-the-shelf-for-years battery.

I'm looking for a new stock battery, one that was manufactured recently, such that it doesn't suck.

Thanks.

Mugen batteries:
http://shop.eten.hu/mugen-power-1800...n810-e71.html#

I'll 2nd Mugen's 1800mAh battery. More power in the same space as the factory battery.

I just received in the mail two batteries from eBay clearly in the "blatant knock-off" category (looks the same as Nokia's battery, but no Nokia label...). First battery is getting about 2-3 hours of charge. Not so good. I'll try the second, but it looks like this buyer should have bewared a bit more & I may be going Mugen before long!

As the proverb says, you get what you pay for.
(Spanish variant: "In the end, cheap is expensive")

here is one for $2.50 . I bought one for $3.50 it works great
http://cgi.ebay.ca/BP-4L-Battery-for...item3a5b2258b2

smackpotato, are you getting the full six hours of usage (not standby) with that battery? I was getting about two hours as I said, and that's just not going to work for me. By contrast, the Mugen batteries referenced above are $30 but supposedly gets eight hours of use.

I can third the mugen battery. I replaced my Nokia original w/ the 1800mAh one and I know have several days of standby time and a good hour of heavy usage time then I had before. Probably the best upgrade for this device w/out whipping out a soldering iron.

ok for $2.50 you dont get a great battery. maybe not even a good battery. i leave my tablet on the beside table over night and it remains charged. I plug it in durring the day. for me this is sufficiant

I got a Pisen battery from Dealextreme for $7.50 that seems to work pretty well: http://www.dealextreme.com/details.dx/sku.39142

They also have a $3.10 one that I recognize as similar to an awful generic BL-5C that I bought from them, that has about 1/3 the capacity of the original. The Pisen seems pretty comparable to the original Nokia cell in my E63 though.