I just switched to the NiZn batteries for my DX3 and DX4. They have a normal voltage of 1.5 instead of the 1.2 of NiMh/ NiCd. I did a test run a couple weeks ago and left them on from the time I got to the track until I packed up 10 hours later and went from 7.1 volts fully charged to 6.5 volts. Took about 35 minutes to fully recharge.

Check them out on E-bay ( possibly other places). 4 2500mAh batteries with charger and free shipping for $25 is not bad. Just bought 4 more last week for my daughters radio.