How to charge RX-pack during flight?

While visiting Habo Helimeet this year I saw something interesting in one of the Miniature Aircraft’s Whiplashes. There was actually a charger for the RX-battery on it, not new by it self but the quality of execution really was worth a closer look.

MA Whiplash with RX-pack charging

While looking at the heli there was a small electric engine on top of starter-shaft:

I knew what it was for but I was curious on the technical execution so I hunted down the owner of the heli and found out that Raja Bortcosh was more than willing to talk about it.

MA jewel RC Generator

The need for the system is simple, Raja’s Whiplash is a gasser with flighttimes up to 20 minutes or more, and instead of having a big and heavy RX-pack you can have an generator onboard and use a smaller, lighter RX-battery instead.

You mount the engine on top of starter-shaft with a coupler, system takes very little power from the gas-engine and in Raja’s case this is done really nicely.

The wires from motor are going to electornics Raja have made himself, basically it’s a AC to DC converter and regulator, function principle is the same as in our cars. Electronics are small, barely seen under the gyro:

How it works in use

You put the RX-battery-switch to ON, start the gas-engine and generator is giving power. Simple as that. As Raja demonstrated you can even unplug your battery while engine runs and everything works. So simple yet powerfull.

RC-Heli flying really cannot be easier than this. you have a gasser heli, no need to charge any batteries except for your transmitter. Take your transmitter, heli and some fuel to field and practically fly all day long. This really is sounding like an tempting alternative to bringing charger’s, generators, fuel for the generator etc to the field…

Weight for the system is less than 6 ounces (170 grams) so that really is not an issue!

And it’s available!

And yes, you can get it! You can contact Raja on the email rbort at, he’s been doing these for years and the quality of parts etc was better than some manufacturer’s are sending us!

Prices are around $215 and the mount around $75, have a chat with Raja to your heli :)

Raja, it was a pleasure to meet you, enjoy your long flights!

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