Man, you made me dig through some old boxes to find my Nokia N800, the predecessor to your fancy N810. It's basically the same thing minus the built in keyboard and GPS. I bought it nearly 20 years ago from the now defunct Circuit City store chain. I found the device but I haven't located the Nokia charger that goes with it to see if it still works. I seem to remember doing some upgrades to the Maemo OS and customized the desktop with a Star Trek LCARS UI theme. It will be amazing if this thing still works because it's such a unique device.
If it takes the same charger, it's an AC-4U. I still see a number of those listed on eBay. Nokia no longer makes the batteries as far as I know, but a lot of Chinesium devices used BL-5 batteries, so you should be able to find one of those as well.
I know I have the charger somewhere, but the battery is probably toast. I'll look for some chinesium batteries to see if this thing is still functional. It might be worth playing with if there's still some life left in it.
I did notice the repositories for mine are still up, and I was able to install new software. All the certificates are out of date and the web browser is really old, so the Internet at large really doesn't work well...
(post is archived)