I just got this new N800 and I plugged it in and it began to charge. I waited about 20 minutes and unplugged it and put in the memory card.

Then, I plugged it back in and it doesn't show that it's charging...???

It also won't turn on.

I removed and replaced the battery and it still won't turn on. What's the deal?

20min?? i think you should leave it for few HOURS the first time.
remove battery again and wait few minutes (5 to 10mins) before replacing it.

Perhaps others can help you better.

Good luck.

Thanks, I'll try.

I removed the battery for 10 minutes, replaced it, and then plugged it back in and nothing on the screen came on.

Should I try my Nokia 770 battery?

Nokia 770 Battery is the same and it still won't turn on.

What the hell???

It charged initially, until I unplugged it.

With the Nokia 770 Battery, it is now suddenly charging.

How long to charge?

I'd leave it at least 6 hours; it's also possible (depending how "new" it is; how long it sat in a warehouse) that it's got the infamous poweron problem, so the first thing to do after you get it charged is to flash to the latest OS...

How long did you let it sit plugged in before deciding it wasn't charging? If the battery is very low I've seen where the unit needs to be plugged in for quite a while before it will even show that it is charging.

So I would swap the batteries to go back to the original battery and let it sit overnight. I suspect you'll have a good charge in the morning.

Try following the instructions that came wih the N800. They advise you to fully charge it when you get it.

Now, it'll only stay on if I turn it on with it plugged in, but I cannot turn it on unless it's plugged in first. I will let the old battery charge overnight.

Now, how do I "flash it to the new OS"...?

Which OS is that? OS2008?