I got the http://www2.towerhobbies.com/cgi-bin...?&I=LXXB72&P=0, C-cell type of Mike recommended with spacer so you can put alakaline battery but I never need to change to alakaline that the charge seems to last forever as long as you don't have engine problems.

I too say go with the cheapest. I put it to the charger at field, through the power panel for 15 minutes and don't charge it at home. The last time I charged at home was probably a month ago.