I am not so sure that the Nimh is your problem. I am using a 3300 mah pack on my P70 kero AND my Titan kero. I get three perfect starts and flights per charge. IF you can touch the plug and it is only warm to touch the voltage may not be high enough. I found that the old plug worked at 5.7 volts but the new ones needed 6.5 to provide ignition. Another thing is to make sure that the kero is all way up to the keroplug for ignition as the pump pulses only small amounts of kero into the plug.

D.W.