home made battery box

You can buy a cheap twin D cell holder at Radio Shack(or rip one out of an old talking teddy bear), yank the wires off and rewire it in parallel with thicker wires that lead to your clip. Good quality copper conductor that supports several amps is a MUST. Speaker wire or lamp cord. It's best if your holder has copper leaf springs instead of the chrome steel coil springs, but either will work. Solder all connections.

I bought a Thunder Tiger Kwik Klip which is a piece of junk because the plastic rots. But I removed the electrodes and screwed them to a wooden clothespin and it works great on all engines. The wires are good. They are easily available, usually at the LHS. It has an inline switch too. Don't leave it connected for any length of time in the Test(Off) position because a trickle current still flows.


After trying many brands, including Energizer, I also recommend Rayovac D cells. They keep working much longer for me. I buy 8-packs that come in a convenient plastic box and keep a pair of spares in my flight box.

thanks again rusty

I made a pack for my friend Patrick, using four Duracell "D" batteries and the plastic blister pack they came in. He's been using it since Spring last year. I soldered a wire around the batteries' ends and wrapped the whole thing with strapping tape.

The plastic box keeps out dirt and prevents shorting while it rocks around inside Patrick's metal toolbox. I think the extra two cells also help clear and fire the occasional overzealous priming his engines receive !

I use 3 single D-cell holders from radio shack, in parallel, fastened to a board, with binding posts. The 3rd battery really helps for winter flying.

I also find the 3 batteries last significantly longer over using 2. I am sure 4 would perform even better, but I am not remaking my setup.

Phil

I'm thinking of cutting open a 6volt lantern battery
and using a pair of the cells in parallel. 3 might be a bit
much. Open for comment.
Bob

I run two D-cells in parallel. They get replaced each spring, whether they need it or not.

What is cheap?

These are only $8.95 and wired correctly:

http://coxengines.ca/cox-starter-battery-box-no-clip.html

I agree, the cost of materials and time to make one makes $8.95 seem pretty cheap to me.

When I was a kid, No.6 cells were very expensive, and the cox starting batteries tended not to last, probably due to being past their sell-by date by the time I bought them. I used to wait for radioshack to have a sale on D-cells. I'd get 8 of them, bundle them like cord wood, and solder a wire around the ends. I'd put a little block of wood between two of the end cells with two brass screws in it for connections. Then I'd make cardboard end covers, and wrap the whole mess up with masking tape. (cause it was the cheaper than electrical tape). One of these would last me about a year or two IIRC. A couple of tricks: Rough up the ends of the batteries with sandpaper where you intend to solder. Use a big iron and work fast, so you don't heat up the insides of the cells.

kevbo wrote:...Rough up the ends of the batteries with sandpaper where you intend to solder. Use a big iron and work fast, so you don't heat up the insides of the cells.

Good advice. I always worried about damaging the internal connection to the end plates.

I've had no luck soldering to D cells. Yes, I used a big iron and tried to work quickly, but when I was done, both cells were reading dead - zero volts.

that is very cool im making one today

Pretty slick. Funny how the simplest things turn out to be the best solution.