2 cheap no-name spares bought from a company I can't recall (not off ebay), plus the original nokia battery. all still work great ( = up to 2 hours use watching on-tablet video and/or web surfing and/or skype) at least 2 years on; I tend to swap them when/if one runs down, then leave it in place after that as usually I can just recharge - except on plane trips. an external charger sounds handy, but in truth I am able to find time to recharge them all before using up all 3 at once.