A123 Hypersonic Charger Balancing/connector

[t-maxxracer32]

71sight you know im running 6s a123 on my revo lol why did you ask that?

[snellemin]

Originally Posted by brijar

I will be following this walkthrough on how to disect them, but I will be making two 2s packs and two 3s packs, so I can run a 2s, 3s, 4s, 5s, 6s, 7s, 8s, or 10s configuration, or a 2s2p, 3s2p, or 5s2p configuration. I'm not sure how I'll be assembling them, because I don't know how to solder to aluminum. If that is too hard, I will just configure the packs without soldering, like this:


I'm not sure how the bus bars will hold up, but I think they will be ok. I think for the 2s packs, I'll just bend the batteries over so that they are end-to-end. I'm not sure what I'll do with the 3s packs, as my rusty's chassis can't fit 3 in a row, or 2 side-by-side. I'll think of something:027:.

Brijar!!!

BTW, the pack is somewhere in MD right now :D

If you get the FLM Rusty chassis, you can fit 3s flatpack with ease.

[brijar]

Yeah, I thought about an FLM chassis, but I would rather spend the $60 on better electronics. I have yet to get a Mamba 5700, so that's another $180 down the hole, plus the $100 or so for the charger. I'll just do some custom cutting on the chassis to make the packs fit. I'm sure I'll think of some way to do it.

Now that I think about it, I think making the packs SxS would be better to fit in my boat. What I may do to my Rustler is dremel down the little lip by the battery tray so that it is flush with the chassis and I can put the A123's in there SxS.

Brijar!!!

[brijar]

Well, the battery just came in a couple hours ago. I have already dismantled it to just the cells. I measured the whole pack and it read about 32.9v-33v. I left my soldering iron down at the lake with my other tools, so I won't be able to put leads on the packs yet. I have taken a few pictures during the process, so I'll post those later. We'll see how it goes from here. The charger and power supply are next on the list.

Brijar!!!

[t-maxxracer32]

what do you use to measure the voltage count? id really like to get me one of those.

thanks!

[brijar]

I just used a volt meter. I got a couple from harbor frieght, which is a very good place to get tools for cheap. I got one of these, only mine is yellow. It has worked very well for a long time. You could also get one with a backlight for easy reading, but it costs a bit more. They are very useful to have around, especially if you do a lot of work with batteries and voltage.

Brijar!!!

[Finnster]

Originally Posted by t-maxxracer32

what do you use to measure the voltage count? id really like to get me one of those.

thanks!

That would be a voltmeter, available at most home supply stores (home depot), Ratshack, hell even pep boys for cheap ones. :027:

I was basically doing the same thing last night. I took my pack apart and prepped the cells. Stupid thing tho is I was easing the cells out of the casing, when all of a sudden it just went and all the cells crashed to the floor looknig a like a string of sausages. Worse yet its there was a little spark. :o One end has a little scorch mark, but for the life of me I can't find what bit it shorted against. My batt luck has been a bit down lately, despite the extra care I've given.

However, its not too bad. So I'll just see. I tested every cell, every one was 3.301V, so I would say currently well balanced. I'm not sure if i will add balance taps. I prolly should/will, but many others have stopped balancing as it seems they tend to self balance.

I made two cuts in the tabs to create a 5S pack and a 2S and 3S. I shooglued them together (like making nimh SxS), and tonite I'll solder a bit hopefully. I'm going to offset the packs to minimize the width. Looks like final width will be just over 50mm, about same width as TrueRc lipos, so should fit in my batt tray w/o mods.

(Poorly) Illustrated:
-ooooo+
.-ooooo +

versus as packaged in 10S
ooooo-
ooooo+

[brijar]

I've done some looking around, but I can't find if anyone has successfully used the Dewalt 36v 1hour charger to charge these batteries. That would save me a lot of money if I could just buy one and do a little bit of rewiring. I wouldn't even need a power supply.

I will have 4 packs that the Hypersonic charger can charge, so it will take me an hour to charge all 4 at 15 minutes each. The Dewalt will charge all 4 packs at once in an hour, but costs a lot less on Ebay. I guess I wouldn't have to do very much rewiring, but just make a harness that plugs into the balancer thingy that I took out of the pack, and then attach the balancer thingy to the charger.
The only thing I don't like about that is that I won't be able to charge just one or two packs at a time. I'll have to have all the packs discharged about the same before I can charge them.
I think I may just stick with the Hypersonic Charger.

Brijar!!!

[BrianG]

If you don't mind sitting around watching the charge, and you have a decent NiMH charger, you could simply charge in constant current mode only. When the pack voltage gets to 3.6v/cell, continually reduce the charge current to maintain that 3.6v/cell voltage - basically simulating the cv stage of the charge...

[brijar]

Well, that's the thing, I went cheap in the beginning, and now it has come back to bite me you-know-where. All I have is a Duratrax Digital Piranha charger and a Dynamite Twin Peak. The digital one is about as close as I get to being able to control the charge. Whenever I charge, I can look at the voltage readout, but it always says like 10+ volts for one of my 7 cell GP3300 packs, so I wouldn't know when to stop the charge. I also notice that that charger pauses every once in a while and drops the charge amps to 0, then goes back to what it was set at.
Thanks for the idea anyway.

Brijar!!!

[Mister_Anderson]

Sorry about stealing the thread but here I go anyway.

So what I'm gathering from this thread is that the hypersonic charger will charge cells of 3.6v not just 3.3v?

It doesn't mind capacity differences?

What rating are the Dewalt pack cells?
What MaH? Discharge C rate?

Thanks.
Mister_Anderson

[brijar]

No, the Hypersonic charger charges 3.3v M1 cells to a full charged state of 3.6v, but they drop back down to 3.3v very quickly and remain there till almost the very end of the charge.

As far as capacity goes, it will charge any capacity until it reaches 3.6 volts per cell, up to 3 cells.

The Dewalt cells are the same ratings as the A123 Racing cells, but they may be lower quality units. Sometimes you may get a bad cell in a Dewalt pack that doesn't hold full charge voltage or capacity.

Brijar!!!

[Mister_Anderson]

Thanks.
What capacity rating are the Dewalt cells?

Thanks,
Mister_Anderson

[suicideneil]

A123 cells are 2400mah, unless I am mistaken.

[wallot]

Originally Posted by suicideneil

A123 cells are 2400mah, unless I am mistaken.

you are.
they are 2300mAh