So I bought a new battery because my n810 wasn't constantly recharging (any time I tried to recharge it, it went into a recharging loop where it'd recharge a little, reboot, recharge a little, reboot, etc. until it stopped recharging). I bought a replacement battery and installed it and now it seems to be charging very well.

Anyone know where to send the old (dead, swollen even(!)) battery?