[mikester]

There are three main RC battery types. Nicad, Nimh and Lipo.

Nicads take a lot of abuse, the others don't.

Abused Nimh just die.

Abused Lipos tend to catch fire.

For what you're doing you should stick with cheap nicads or nimhs.

The higher the amp rating the longer the battery will last and the higher amp draw it will support. The 'amp draw' is commonly referred to the 'c' rating. So if you have a 1000 mah battery that is 1 'C' it will support whatever voltage it is drawn at 1000mahs. If it is 10C then it will support whatever voltage it is drawn at 10*1000mahs.

I have 2 7 cell, 2000mah Nimh batteries that have very little use on them that you can have. I'm near the beach at the end of the 105.

7 cells are higher voltage than 6 cells, the higher the voltage the higher your amp draw will be. The higher the amp draw - the shorter your run times will be unless you put high amp batteries in there to compensate.

What are the amp rating on the batteries you have?