I have brand new batteries purchased after the original died. it would no longer hold a charge. so i bought some new ones. none of them perform like the OEM battery although they are marketed as OEM.

Anyway, I can take the device off the charger before i go to bed and the battery is dead the next morning. This happens with all 4 batteries that I have. Is there a way to troubleshoot this problem?

It sounds like there is a process draining your battery, but it seems strange that it would happen when you started using a different battery. Maybe you can use the top command to see if it's related to a specific process. Where did you buy the new batteries? Is it possible that they're just no good and don't hold a charge?

Try this.

Get a small piece of construction paper or something like it and use it to push the battery harder against the contacts.

The reason: Nokia only ordered enough batteries for each N810 plus about 10K in reserve.Those were sold out before the N810's. The Chinese shop that knocked off the battery built the forms for the plastic cover made a 10 micrometer mistake that makes all the batteries since the width of a thick piece small on all dimensions.

Search this forum (probably a part of it specific to N810 or N800 or Diablo) for MuGen. As long as you figure out electrolind's trick to jam the battery closer to the connectors, they are good batteries.

I cut pieces from an old plastic card.