My battery capacity is decreasing very fast,... moreover now I can charge with a charger 5.2v and0.5mA (it isn't from nokia) but I can't with a nokia (AC-3X) 5V and 350mA

Months ago I bought a new battery in ebay, but the real capacity was less than half of my original nokia battery instead of the capacity printed in the battery ...

I am afraid to buy a new one in internet because there are cheap and more expensive but how could i be sure the it is a good battery? have you bought any?

And buy a original nokia in phone shop is too expensive...

u can get the origin nokia MUGEN battery thats double the capacity (2400 ish mah) for around $70 australian.

I heard this one is the best http://www.dealextreme.com/details.dx/sku.32444

I doubt it's genuine, anyway it's not for the n800.

This would be good for my N800.

Yes?

http://cgi.ebay.com/1500mAh-Battery-...item3a5ad9737e

It doesn't look like a genuine Nokia one (those are Li-Polymer, not Li-Ion).

and the differences between Li-Polymer, not Li-Ion?

Other point is I understand the capacity advertised in cheap ones is false, because my ebay battery is very very light, and the duration is a very very short..

I bought quite cheap batteries for some nokia phones like N73, and the duration was good.

Do you think we could use batteries from other devices?

The N900 battery is the same as for Nokia 5800.

The AC-3 is hardly enough powerful to charge the battery of the N900. It does charge when the phone is on, but very very slow. When you actually use the phone, e.g. use data connection, battery is still drained, although a bit slower. At least that is my experience with this power supply.

The AC-5 (890 mA) is okee though.

So what's the cheapest battery out there for my N800, Ima?

I thought that's the one I bought a year ago and it's held up quite nicely.