Hi Rui.

Well, I went to radicalrc.com and looked over their battery packs and picked out from there. I generally use NiCd's but lately, I've been using the lighter NiMH packs. I get a good 1200mah 6 volt that charges just fine on my Sirius field charger.

I did find that the OS 46 that I first used on my four star seemed sluggish. I was never really happy with it on the four star so I put the 50 on. It really changed how the plane flew. Great vertical and good aerobatics. I don't know what you are looking for, but the LA should be a good starting point.

I recently got a good deal on a trainer, a Hobbico Super Star RTF, that I picked up for the club. It came with an LA 40 on board and I put that engine on the Super Star. I also had a Macs muffler (all in one) that I used. Man, that is one performing trainer.. ha.. yet the student that flew it a short time ago seemed not to notice that added power. I certainly did.

Anyway, Tower has a pretty good selection on batteries. I opted for the NiMH's for the weight differences on my pattern plane where I use two of them (parallel, each on it's own switch and going to a separate RX channel).

Dick