which lipo?
 

Here is my current setup.

Tc4
Tekin Rs
Losi 17.5
Jr rs300 rx
Futaba 9551 servo
Single fan heat sink

I currently have two different lipo's
Team orion 3400 25c
and a soft pack 5000 25c (it is a green soft pack, I forget the brand and left them at my brothers house)

What kind of mah rating and C rating will I need to get me through with out loosing or loosing as little power as possible. I know there are lipo's up to 5200 40c, but they are very pricey. So I ask wondering how much I need in terms of mah and C.

--pakk

If those ratings are honest, the 25C 5000mah shouldn't have any probs. I'd believe the 3800 would be able to run your setup as well, it just has a little less cushion. Run it and check lipo temp a few mins into the run - if its getting hot, it can't supply enough amps. That's prob beacuse the rating is optimistic. There's no standard way to rate lipos and one companies 30C is another companies 25C or even less in some cases.

The 5000's are soft packs that I use to practice/play around with. That is why I am looking for another pack. I haven't used the orions yet, but I will next time I go out and monitor the temps. What is hot for a lipo? My soft packs always seem nice and cool. Probably because they have more than enough power.

--pakk

Mine get just warm enough after running so that you know they have been used. Warm for a lipo is 110F, serious trouble is 140F.

You want you setups "overbatteried" - that way you get a cool batt after running, long batt life and happy electronics. It used to be you just couldn't afford to do that cause the higher C rated ones were so expensive, so people had to run on the edge. Thats changed, you can afford to get what your setup needs. I bought 2 3S 25C 5000mah NeuEnergy pacs last nite for $130 shipped, they were $58 each, I about fell out of my chair, 6 months ago they were $170 each!

Def give Orions a look, they are top rated cells (Kokam), btw those are honestly rated! You can count on them delievering what they say they will. I didn't catch on that the 3400s you were talking about were Orions. I see that now....