For battery replacement use Duracell DR-11. These are better then the originals. They are fat batteries and run for a good hour. You will need to rig up a retainer strap around the camera in order to hold them in place. Thats the only draw back but well worth it.
These are camcorder batteries with a set of 2 shoes and 3 shoes. They are used on Sony or JVC. The unit uses JVC type batteries.
As for the charger just order a charger for the DR-11.
You can still get parts from FLIR Canada, Toronto.
Good luck
Carl