K.I.S.S. power system?

[ExtraJohn]

Finishing off my 1/4 scale CAP for IMAC. First gas airplane.

6 servos , 1 per ail, 1 per elev half , 1 rud, 1 throttle. Not HV servos.

original plan is 5 cell 4000 mah or so nimh, ibec to ignition, 1 switch, Futaba 8ch 2.4ghz receiver

approx finished dry weight just under 12 1/2 pounds with this set up.

I don't think the difference in weight between a regulator and other battery type will make much difference?

keep or suggest changes please

 

[Xpress]

I would run a set of 2S LiIons and use a regulator set to 7 volts. That way you will get a consistent power output from the servos, rather than having them fade throughout the day when the nickel cell packs sag in voltage. Also, a LiIon setup with regulators would weigh less than a set of big nickel cell packs.

 

[Bartman]

a compromise between what you're planning and what Xpress said would be to use a 2300 mah 2 cell A123 pack without a regulator.
6.6 volts which most modern servos can handle and it's still simple being that there's no regulator. A123 packs are easy to charge if you're not familiar with them. they also don't carry the fire hazard that LiPo's do.

a good charger can be had for under $50, just make sure connectors are all compatible

 

[Jetpainter]

I like A123's as well. you get a little bit more but don't need a regulator.

 

[ExtraJohn]

I'm not familure with the A123 batteries.

I do have the ability to charge up to 6s lipo and pretty much anything nicad/nimh. Cost is also a factor, I would like to not have to buy a whole bunch of new stuff if I really don't need to. I can make my own packs from loose cells as needed as well.

I have been running Fromeco set ups in my helis for ever so I'm familure with them.

 

[Jetpainter]

Most chargers now days have a LiFe or A123 setting. You didn't say what brand of receiver your using. Some like Spektrum that I fly don't like low voltage at all that's why I run A123's.

 

[ExtraJohn]

Futaba 8ch 2.4ghz receiver

 

[ExtraJohn]

My charger is a Thunder Power 1010-c

 

[Bartman]

the manual for that charger only lists Lithium Polymer and Lithium Ion so it doesn't look like it'll do A123.

a dedicated A123 charger wouldn't cost much and would be worth it to run A123 packs. I'd prefer that over using LiPo's and a regulator just because you have the LiPo charger.

 

[ExtraJohn]

When I finish the cancer treatments and start working again, I'll budget a new charger and a123 cells.

Thanks for the information.