djmp69

Ok, so first I want to apologize if this is in the wrong forum, but this is the best place my question seemed to fit. A little background, Ive been in the hobby for years, yada yada, and I moved on from NiCads to NiMH, and have been very satisfied with the performance. Well acquainted with battery etiquette, expectations, etc. I've recently started looking into the LiFe chemistry, and I got a pretty good handle on it, I think, but the one question that beats me is about capacity, more specifically discharge. Normally, in a 50cc plane, I use 2 6v, 5 cell packs for not only redundancy, but power as well. I do alot of stick bangin, and alotta "hold that" maneuvers, so between loads and stall currents, I want to have a lil headroom, and I figure if I have two 4200 mah packs, I can fly all day PLUS have 8+ amps to work with. So far, so good, my planes are great, respond like I need them to do.
I really had no intention of fixing what ain't broke, but when I was looking at the specs of a few LiFe packs, I wondered if maybe shaving some weight was on the horizon. I also noticed that the LiFe packs have multiple leads coming out of them. For my situation, this feature is moot, because for redundancy, if a pack goes bad, then it doesn't matter how many switches you have connected to it.

So my basic question is this. Comparing a 6.6v 2100mah 10c 13wh LiFe pack, and a 6.0v 4200 mah "high dishcharge" NiMH pack? The specs on the LiFe pack say 10c (21 amps) max continuous current--am I correct in understanding that one of these packs will give me the amps I want plus compared to a NiMH pack with twice the mah capacity? Now trust me, I understand that mah is mah, and 4200 is going to give me longer supply than 2100, but I am more concerned with available amperage, ALL my servos having the power when I want it. And if a lighter battery can supply that punch at a lower mah, that's fine, especially if I can charge them more quickly.

I hope I'm making sense here.

All the reading I've done, everyone seems to talk about overall discharge level minimum for the packs. I'm more interested in max discharge current respective to each chemistry. Anyone have any advice on this?

Thanks!

Gtarling

Use A123 cells - the 26650 size are 2500mAh and good for 60 Amps. They also don't need any form of regulator. I use them in all my larger models. Lesser cells may not be capable of delivering the current you need.

All Day Dan

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This will help. Dan.

The A123 FAQ for Giant Scale and IMAC

djmp69

VERY informative and helpful, thanks!