A123 Hypersonic Charger Balancing/connector

[brijar]

I just bought a Dewalt 36 volt pack from a big seller on ebay (2800+ feedback @ 100%). He originally messed up the auction and put 9.99 Buy It Now:eek: + $10 shipping, and I grabbed it quick as lightning, but he caught the mistake, and refunded my money within an hour. I asked him what kind of deal he could give me on it so that I could leave him good feedback, and he said $75 +10 shipping was as low as he could go. I thought that was still a pretty good deal, so I accepted that. I learned just a while ago that he's going shipping it for free:018:. So I get a brand new Dewalt 36 volt battery pack for $75 shipped, so $7.50 per cell, which is pretty good, I think.

Now, I will also be getting an A123 Hypersonic charger for a little less than $100 shipped, and I was wondering what kind of connector I will need to use the balancing thingy in it? I will be making two 3s packs and two 2s packs from the Dewalt. I would really like to be able to go up to radio shack and get a few rather than order it from the net. Is there any way that I could get my own to put on it so I don't have to buy one off the net? It would only need 2 wire slots, right?

Also, if I buy a computer powersupply to run the charger, how many watts will it need to be at least to charge at 10 amps? I can get a good deal on a 350 watt one, if it will work. The charger says, Input Voltage: 10vdc - 15vdc.

Thanx,
Brijar!!!

[zeropointbug]

That's a great deal indeed! ~1/3 the cost of LiPo, very nice.

I just bought two 36v packs as well (~$100 each), I am building a 7s2p pack for my truck to run a Neu 1512/3D (1700kv), it should go pretty good, and stay a lot cooler than my 7XL on 5s2p A123.

Anyways, to get to the point, you need an 'Anderson' balancing connector. I don't know where to get these at the moment though, and I am not sure if there is certain wiring sequence for this plug. I'll see what I can find.

Nevermind, they don't have them anywhere. Try A123 Racing directly; I think they have just the balancing plugs for sale. The down side is that you have to order direct...and it will probably cost you more than it should.

[snellemin]

I use a 365 watt PC power supply with my hypersonic charger. I have the Hypersonic charger and 2 NimH chargers in use at the same time and the power supply is not even breaking a sweat. Figure 20 amps max.

[silentbob343]

Pretty good deal?

That's a great great deal.

[brijar]

Yay, he should ship the batteries out today! Now for the wait:025:.

Ok, that's good to know about the power supply. snellemin, is there any way to put a different balancing connector on your Hypersonic charger? I would think that if it had a small lead to the connector, you could cut it off and replace it. If it was more like the connector on an internet router, then you'd have to get inside to get to the wires.

Does anyone have just a spare male anderson balancing connector lying around? I could pay for shipping if you'd be willing to ship it to me:027: at 64015.

It's just about time to order the charger and power supply. I think I may try and get a 400 watt PS on Ebay, for around $14 or so. Wouldn't want it to have to work hard to power the charger, now would we:007::005:.

Brijar!!!

[t-maxxracer32]

im in the process of looking around for some more a123s. dont feel like spending 80 bucks for the 3s1p packs that i have...

are there 20 cells per dewalt battery?

also once yuo start to put them together you think you could take some pics for us people who dont know how to do it?!?!?!?:027:

i think it would help everyone out alot (or just me :005: if you showed us how to configure everythign!)

[brijar]

Hey, I sure would take some pictures. There are only 10 cells per Dewalt pack, at 3.6v per cell, they give it the 36v rating.

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

[zeropointbug]

I got my two 36v packs in Brijar. I have taken pictures of the process so far, and will post a thread on making a 7s2p pack, single pack.

I already posted that link in another thread, i forget where though. :032: oh well:005:

You can solder to the aluminum cans, it is coated with nickel (or something, not too sure), so it's easily soldered, but not recommended with the A123 (or lithiums for that matter), you should try and make as few solder joints as possible.

[t-maxxracer32]

cool looks good! i might take apart the packs that i have right now to see how they did it. that will probably be my best bet.

[brijar]

Well, I would really rather solder the cells instead of using the spot welded bus bars that they come stock with. I know almost all battery companies advise against soldering their batteries, but NiMH's solder just fine, if you are quick. I have an 80 watt Weller iron, will that be quick enough to not heat up the A123's too bad, or is there other concerns I should be worried about when soldering?

Thanx,
Brijar!!!

will these cells work with a mamba max esc? tmaxxracer why dont u answer to my pm???????/

[Finnster]

There are somevery detailed and great threads over @ RCGroups in the batts section. the forum is more for planes, but same things apply. Most there were just using the bussbars. They seem to hold up well enough, but they don't draw the huge currents we do for the most part. There is one bar that is thinner, possibly acting as a fuse. Most leave the bars and sodler some copper wire to assist where needed. I'd post links, but that site is blocked from work :010: Search A123


Also, I thought I had read where someone did some testing, and the V drop w/ buss bars showed nominal decrease vs using batt bars. Ie, it really wasn't worth the trouble (which is quite a bit w/ the A123s)

[zeropointbug]

Yes, I have read that at 35 amp draw, the stock strips loose 1% voltage, so anything higher is going to have exponentially higher losses, naturally.

I have talked to A123 Systems, they sounded quite stern about soldering their cells, they told me cycle life would be significantly decreased. Definition of 'significant', I don't know, but they should still last far longer than lipo.

An 80 watt iron should do the trick. I have a 300 watt iron I use for this kind of stuff. Also, one spot you should beef up is the thinner strip, it is there to act as a fuse for too high of currents.

BTW, from the 'developer kit' I bought last year when A123's were first released, and the cells I got from the two packs, there seems to be quite the quality difference. The older cells I have seemed to have been 'clones', they were like 'pro extreme team matched' so to speak, these new cells from the dewalt packs all vary in voltage when fully charged for some reason.

But I will wait until I get a few runs into them first, in case it's a 'break-in' issue or something.

[suicideneil]

Originally Posted by 71istight

will these cells work with a mamba max esc? tmaxxracer why dont u answer to my pm???????/

Take a chill pill. Any battery will work with any esc, its just a case of matching the voltage & amperage requirements of your set up.