first thing do you own a battery charger that will charge nimh batteries? if not buy one that that has auto peak, and its nice to have one with ajustable amp and a millampcounter

I charge all my nimh at 5 amps and check my counter for corect mah

for a cheap battery , I would buy peak or orion twin pack, they're for E-max good cheap
batteries for playing around or good enough for practice batts

I bought 6 of these batteries and built hand made batteries out of them by matching the cells