My Multi-1/64th charger

[crazydave]

I think it was Superfly that built a charger with a wall wart and Motorworks base. I've been planning one for a while, and I've been experimenting with a few AC adapters, that I've had a around, but I finally went to the rat shack and got me a multi-voltage adaptor for $10.99.

I remember reading about someone building one of these for bits way back in the early day of bits over at TinyRC, and he was saying he thought 1000mA was ideal, as lower mA ratings didn't warm the batteries. Considering these batteries rated charge rate, I thought that was pretty extreme. I think he was trying to get a full charge in a 45 second cycle.

Anyways, that may seem off track, but that's been my hang up about building a permanent stand alone charger. After determining that 800mA, 600mA wall warts charged a little fast for my taste, I went for 300mA when I finally went to make my purchase.

Then I installed a mini plug in a Motorworks base. Since I had the extra space, I chained together a bit, Thunder Charger, OG Zip Zap, Zip Zap SE, and a mini plug that's good for, Superslicks, Muscle Machines, NKOK RCs, and possibly an Epoch, if I put a voltage reversal switch on it before the plug.

So that covers most of my bases. I can always put a mini jack in the controller of the ones not covered.

I figured since I'd be plugging into the wall, and have essentially an endless supply of energy, a timer cut off would be the safest way to go. I wish I could whip up something with adjustable timing, but the stock Motorworks one works fine for now, it seems to get all the juice through better than some. So mounted that with a single screw down in the corner where it'd be out of the way.

My other hangup that kept me from building this before was how to make a button for the latch on Zip Zap bases. I had decided to just go for it, and slap it together, when half way through, I got the ingenious idea to cut the ends off antennas.

I made a top from the side of a Zip Zap package. Cut holes to fit each base, and spray painted it. It's a little rough, but it works.

Here's the insides before I put it all together.


Then all together. It's a little rough still. Need to trim more off the top to fit it better, and just taped down, until I'm done modifying the insides.


It works great. Charges at nearly exactly the same rate it does with batteries. Charging at the stock "approx. 45 seconds", for 3 cycles was about perfect. I charged up car after car, and never worried about running out of juice. Much more fun.

[45tr0]

I think i speak for everyone when i say ":bowdown:"

That thing kicks arse!

[SuperFly]

Very nice. I like the multi-functionality with the different pads. That's weird 300mA is doing it, I'm running 1000 and have a backup that's 700. Woulda thought 300 would be much lower than batteries put out.

Once you start charging with AC, you'll never go back. And your controller batteries will last for months.

[crazydave]

I remember reading way back when that due to the hit and miss QC on these type of things, the rated number often has little meaning. The 4.5v 600mA one for my walkman was putting out over 6v. My crappy multi-meter don't read over 200 mA, so I can only guess how many mAs it was really putting out. Also I think it depends on the strength of the current from the wall.

At anyrate, I remember seeing a spec sheet on some 150mah cells, and the reccomended charge rate was something like 50mA, and I can't even remember how many hours, or minutes. I haven't had a chance to find that, but I'd really like to find that, before I say too much about it.

All I know is, this is charging at the same rate I always charged at. Maybe the Motorwork's timer module is limiting the current, so it is the same as always.

You using the timer button, Superfly? How long are you charging for?

[SuperFly]

Yeah, I love my little Motorworks charging button/timer. Hue and I joke about it when we're racing, as we each try to sneak in an extra button push.

"How many times have you hit it?"

"Hmm, I don't know, maybe 3. Maybe 4."


Single cell cars with stock batteries usually get 3-4 hits, dual cells and high-capacity batteries get up to 6. Can feel the bottom of the car get warm but not hot.

[crazydave]

Hmmm, that odd, despite our drastically different ratings, we're getting the same charge times.

Stock bit batteries get 3 charge cycles, and they get pretty warm. They actually start to warm after 2 charges.

[SuperFly]

Yeah, it's probably not great for the batteries, but what do I care, I have a bin full of them. I've yet to replace one because it stopped taking a charge. I have so many cars that I drive, none of them gets taxed too hard. I've wondered if the MW pcb was doing some kind of regulation in addition to the timing.

[Nasphere]

That's weird 300mA is doing it, I'm running 1000 and have a backup that's 700. Woulda thought 300 would be much lower than batteries put out.

heres an idea, go with what the batteries were originally.

4AAAs make 6V @ 800mA

3AAAs make 4.5V @ 800mA

[crazydave]

Well here's something else to consider, at what point in their life span do AAAs put out 800mA? Cause you know they're not punching like they used to after they go under 1.5v, and considering I charge my cars for 3-4 minutes, it takes a lot longer to charge on just my second charge.

[Nasphere]

heres my charger, work in progress...
(inspired by CrazyDave again)




what it will do is charge single, dual, and triple cells from a 12V source, i built an add on that allows you to charge at different rates n such for different sizes of batteries.
I have to build a tiny circuit onto the side to regulate the 12V AC-DC adaptor down to 6V...