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RCMR battery mod used for Rx too?

PostPosted: Fri Oct 01, 2010 8:37 am
by AE25
So i've ordered a few pairs of the 3.7v Li-ion 3000mah ultrafire batteries for the flysky/turnigy 9x battery mod from dealextreme at us$12.58/pr. (don't flame me, this is before i realised there was a review panel at the bottom saying bad things on these particular ones).
since a pair would be 7.4v in 2S... would these be suitable as a receiver/servo battery in a 40 size plane? (kyosho 40 mustang). or they considered too heavy? or is the protection thing bad for running std servo's from?
cheers in advance

Re: RCMR battery mod used for Rx too?

PostPosted: Sun Oct 03, 2010 8:46 pm
by RCModelReviews
I wouldn't use them as a receiver pack for a couple of reasons:

1. they're 7.4V which is too high for most servos. The majority of servos *love* 6V but 7.4 might fry them.

2. they Li-Ion cells aren't designed to deliver high current so under the load of several servos they might just drop too much voltage.

The best batteries to use for receivers are A123 cells (LiFePO4). A 1100mAH 2-cell A123 pack can be made for about US$20 and I use them in everything from my little low-winger with a .21 4-stroke to my huge Mojo60 with a Saito 100 up front.

For larger planes (like my 30% Extra) I use the 2300mAH A123 cells -- these things can deliver over 100A without blinking an eye.

Li-Ion cells are *great* for transmitters though.

Re: RCMR battery mod used for Rx too?

PostPosted: Sun Oct 03, 2010 11:17 pm
by AE25
inerested in where you get your A123 cells from :)
cheapest LiFePo4 cell i can find is us$8.22 (probably not genuine)
Himodel- ... Style.html
are these what you use or would you recommend a better option?

dealextreme- can't find any LiFePo4.
HK have these A123 cells with good reviews.. but pricey. ... ll_w/_tabs

Re: RCMR battery mod used for Rx too?

PostPosted: Mon Oct 04, 2010 6:14 am
by RCModelReviews
HobbyKing has the 1100 and 2300mAH A123s and they certainly appear to be geniune. Pretty good price if you're a platinum member. That's where I get mine.