Batteries, Batteries, and More Batteries

So I got my Brooxes KAP kit home last night and started putting it together. About halfway through it is a step where you modify a servo for continuous 360 degree rotation. No sweat, I've done that four times now, taken pictures, made the web page (got the T-shirt, lost it?) Anyway, easy step. Only catch is you have to make sure you've centered the servo's feedback potentiometer afterward. Easiest way to do this is to plug it into an R/C receiver, power things up, center up the stick on the transmitter, and make sure the servo doesn't keep spinning. So I got out my radio, powered it up aaaaaaandahem... no juice. So I put it on the charger and kept going.

This morning? Still no juice. I opened it up and saw that in the intervening years the battery had done the puffy discharge thing that drives digital doctors nuts. Shame on it! The radio's only... ok, sixteen years old. Twice the age of my oldest kid. >sigh< Can't win.

Actually, yeah I can. Doing robotics gets you into silly things like chopping servos apart to make them spin continuously (which is why I've done that so many times.) But it also gets you into batteries. My favorite battery chemistry, by far, is the lithium chemistries. Both my mini-sumos run on LiPoly batteries, and a friend's much (MUCH) larger project runs on LiIon batteries. Great stuff.

But I was after a direct replacement for the decrepit batteries coming out of my aging radio gear. As luck would have it, though, the same supplier I use for my LiPoly batteries had replacements in-hand! The original was a Futaba NT-8H NiCd pack. All-Battery sells NiMH NT-8H batteries, along with NiMH batteries for the Futaba receiver. Click-click, and now I've got two packs and a charger in the mail.

That may be one of the most rewarding aspects of these hobbies: Taking old "useless" gear and breathing new life into it. Some of the tools in my shop pre-date WW-II. (At least one pre-dates the previous century.) The radio gear for my KAP rig probably wouldn't even pull $20 on Ebay. And yet it's still working (or was the last time I powered it up a year ago), and with new batteries in place it'll help me take aerial photographs anywhere there's wind.

But in the meanwhile, I'm not going to be flying this camera for at least a week. Bummers. Ah well, I've still got some debugging to do on the kite itself. The wind's right, the weather's clear, and I might get a chance to test out the kite tails I got from Brooxes. It'd be nice to know I don't have to worry about nosedives before slinging a camera from the kite line.


Tom