Brett Armstrong

Not sure if your Tx has a low battery warning but the 10CG dose and it is set at 8.5V non adjustable. This causes a problem, if you put a LiPo in place of the NiMh you will have to chose a 2S or 3S. The 2S is too low and causes the low battery alarm to sound constantly. On the other hand the 3S will get below the self destruction limit before the low battery alarm warns you. In short if your Tx is built for NiMh and has a battery alarm, stick with NiMh for a new battery.

Update I have been using some video goggles powered from the trainer port on the 10CG, the added current draw goes close to the 0.5A limit of the R-7805. I have found a new switch mode supply that is capable of 1.5A. The Murata OKI-78SR-5 is smaller and cheaper. I have also done some current readings with the 10CG transmitting with a stock NiMh battery at 10.4V. LM7805 fitted 170mA OKI-78SR-5 fitted 120mA It's not the 45% saving I had hoped for but it is about 30%. If your transmitter normally lasts 5 hours this should give it about another 1.5 longer life on the same battery. Happy flying.

The 5V supply runs most of the transmitter if you swap from a 50% heat loss to a 3% heat loss there will be much improved battery life. The R-7805 will also provide better high voltage performance with 3S lipo. Just added the photos for ease of viewing.

Hi, I just got myself a 10CG and being an electronics tech I couldn't help have a poke around. I found the main voltage regulator to be a surface mount version of an old skool 7805 resistive voltage regulator. This type of reg is about 50% efficient and the higher above 8V the worse it gets the rest is turned into heat(note for those running 3S lipos). The R-7805 is a modern switch mode reg with an efficiency of 97%. The use of 3S lipo shouldn't be a problem as this guy can handle 30V max. It is larger and needs to be mounted away from the original spot but doesn't need a heat sink so that's easy. I haven't done a before and after current reading as my meter was playing up. I didn't have much time so I haven't explained the whole dissemble process. The first pic shows the stock voltage reg. [IMG]http://i1129.photobucket.com/albums/m513/brettarm/LM7805.jpg[/IMG] The second pic shows the heat pad and wires to move the reg. [IMG]http://i1129.photobucket.com/albums/m513/brettarm/Wires.jpg[/IMG] The third pic shows the pcb back in place and the regs new home and the red lines are where the battery compartment is once reassembled(avoid getting wires in this area). [IMG]http://i1129.photobucket.com/albums/m513/brettarm/R-785.jpg[/IMG] I ended up covering the whole reg in shrink tube and cable tying down. Have fun modding.