I have used FROMECO 4800 Lithium Ion Batteries on ECU and receiver in 9 of my jets with NO problems and I can get nearly 6-7 flights per charge. If you want a PREMIUM Lithium Ion Battery use the FROMECO "Pierless" batteries as I have noticed a considerable difference with these. If you like to fly alot and dont want to mess with "down time" this is the BEST way to go. Before FROMECO I used POWERFLITE batteries years ago but they have since gone out of business and lithium ion batteries have come a long way in the last 8 years.