View Full Version : Some battiery Questions
ethinger
08-30-2006, 09:31 AM
Hi.
I'd like to know which is better... to run 2 Trex Battery packs lets say 3s2p at 2100 MAH each packs...
it it is better to run 3s1p 3700MAH? from Evo20?
if the power and duration is about the same, i would like to just fly 2 Trex packs... since i have a Trex anyway.
but if it is better off with the 3700 Mah 3s1p i would just go for the 4s1p or maybe even 5s1p.
pls help. thanks in advance
Gscott
08-30-2006, 10:41 AM
Just for clarification (2) 2100 T-rex packs would result in a 3s2p config of 4200mah. That would be better than the 3700mah from a single pack but I would also look at the weight and discharge rate as well. Running on 4s would be a very powerful setup but I have seen the 3s setup fly and it had more power than I thought it would and it flies very well.
Finless
08-30-2006, 01:05 PM
I flew a Lepton on two 2100 packs and it was just fine! The only thing I didnt like was the double wiring e.g. 2 sets of Deans and a Y cable. You do loose a little through all that wiring due to resistance and more connectors. I know it is probably not worth worrying about but it was messy in my opinion.
Bob
FrittsLogic
08-30-2006, 05:10 PM
I don't know from personal experience(I've only flown 4S emoli and FP 3700), but theoretically, the 4s 3700 should be better on two counts. Obvioulsy the higher volatge yields better power, when desired, and lower current (thus less IsquaredR heat losses). Secondly, if you look at the energy stored in each config, a 3s2p 4200 has 11.1V x 4.2amp = 46.6 watthours. The 4s1p 3700 has 14.8v x 3.7 amp = 54.8 watthours. Also, the FP evo 20's actually hold their voltage higher under load up to the 80% point at which we should always stop flying. So the effective useable energy would be even higher.
Finless
08-30-2006, 05:44 PM
Yea... I do prefer the 4S setup over the 3S2P. Jacks 3S2P was OK but not as powerfull as my 4S setup. This is the video of maiden flight of Jacks 3S2P setup.
http://video.helifreak.com/?subpath=finless/lepton&filename=lepton_test3s.wmv
It was respectable however so those on a budget and already have Trex packs can get by with this.
Bob