[~7.4V 800mAh] alkaline battery pack

I need to create a battery pack with 7.4 to 7.5 volts and 800 mAh (or greater) in the lightest package possable with alkaline batteries. If circuitry is needed that would be fine.

Its for a mid-small sized RC Helecopter

sort by: active | newest | oldest
That's 5.92 Wh.... A 1.5 V 2300mA AA battery is 3.45 Wh, so two will meet your energy spec. Then a lightweight switcher can meet your voltage spec.
physics_dude (author)  steveastrouk7 years ago
And, where can I go to make this lightweight switcher?
How good is your EE ? I'd build one round a chip like the LT3757, but it wouldn't be for the faint hearted.

physics_dude (author)  steveastrouk7 years ago
My Electrical Engineering is  advanced, I just need a good schematic and a list of what I need.
Well the datasheet has what you need in principle. This is not  a design for running on a breadboard, it needs a PCB, and it has to be tiny, because this is a very fast switching circuit. There's a reference design in the datasheet, which should be modifiable for your requirements.
Use  a National Simpe Switcher and make one from www.national.com/pf/LM/LM2623.html#Overview
physics_dude (author)  steveastrouk7 years ago
It doesn't seem like this circuit will meet my demands. remember that it must power a RC Helicopter
You didn't state the discharge current: I specified 800mA to begin with.
physics_dude (author)  steveastrouk7 years ago
The Helicopter is, E-Flite's Blade CX Twin-Rotor Helicopter

It has 2 FK-180 SH motors (Datasheet found here.)
And 2 Sub-Micro S60 Servos (Found here.)
I'll guess at 3Amps then ?
physics_dude (author)  steveastrouk7 years ago
Well, I ran the Helli from my DC power supply and it went up to 4.5 amps at full throttle.
NOW we have some working numbers !