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Old Mar 17, 2010, 02:20 AM
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Dewalt DC9180 1100 mAh A123 Cells and DC9280 2300mAh cells - Photos

Here are some photographs of a Dewalt DC9180 battery pack that I disassembled. I intend on making 3S packs for my RC aircraft.

To disassemble I used a #10 security torx bit for the four screws on the top. Then I needed to pry a little to get it apart due to the locating pins. I desoldered the balance lead connections, then separated the batteries into pairs. I'll separate to individual cells when I make the 3S packs.

Anyway, I thought some of you might like to see the inside of the pack, so here are some photos.

Photo of a Dewalt DC9280 pack with 2300 mAh A123 cells at post #43:

http://www.rcgroups.com/forums/showp...4&postcount=43

Added 5/21/10 A very informative List of A123 posts by Everydayflyer at post #64.
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Last edited by u.rusty; May 21, 2010 at 09:05 PM. Reason: To add link to DC9280 photos and list of A123 posts.
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Old Mar 17, 2010, 06:16 AM
Southern Pride
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Haralson County GA. USA
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June 2008

http://www.rcgroups.com/forums/showt...62#post9999992
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Old Mar 17, 2010, 07:25 AM
Jack
USA, ME, Ellsworth
Joined May 2008
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"..I'll separate to individual cells when I make the 3S packs..."

Why? The jumpers that are on them save one soldering evolution and work fine.

If you are worried about losing less than 1% of the voltage at an amperage rate that would be insane for the 1100 cells, it might be worth the trouble to solder all the jumpers.

And even then, if you are trying to lessen the resistance, it makes more sense to leave the existing jumper and add another jumper wire on top of the tin jumper.

Also, those thin tin strips tin and solder very nicely and using them reduces the risk of damaging the seals or electrolyte by overheating.

I also use the tin jumpers when using the cells in the lengthwise or "stick pack" mode too. You can bend the jumper back on itself to put the cells end to end. Just do it so that a small radius is formed and put a spacer between the folds to avoid the fold being pinched flat.

Here is my take on building a triangular stacked 3S pack:

http://www.rcgroups.com/forums/showthread.php?t=937290

Jack
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Old Mar 17, 2010, 11:57 AM
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Winnipeg, MB Canada
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Quote:
Originally Posted by u.rusty View Post
To disassemble I used a #10 security torx bit for the four screws on the top.
And if you don't have a set of security torx's, give the pimple a couple of whacks with a nail set punch and use a regular torx. Tex.
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Old Mar 17, 2010, 01:13 PM
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Germany
Joined Dec 2003
5,280 Posts
Nice photos, thanks.

But better leave the cells as much connected as possible, and don't remove the welded tabs. I use the tabs that were already in place in my 4s packs that I made of the VPX cells. The tabs are enough for the current the cells can deliver, and A123 cells are known for not liking to be soldered on. It works, but welded packs require less balacing than soldered ones.
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Old Mar 17, 2010, 01:48 PM
Southern Pride
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Haralson County GA. USA
Joined Oct 2004
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I guess it depends. Some the 1100 cells I have used had very poor spot welds and would in fact pop loose with the least bit of pressure. The 1100 cell are metal cases and unlike the 2300 cells are extremely easy to solder. Adding 12 ga. solid copper connection bars made a significant improvement on the 4 cell packs I made ,especially at and above 20Amps. burst.

Charles
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Old Mar 17, 2010, 02:40 PM
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California
Joined Feb 2008
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The cells are all in parallel pairs.

If I want to make 3s packs I don't have any choice but to separate them. I could make 3S2P packs, but that would be too heavy for the plane I plan to use them with. I was hoping to find some pairs of cells next to each other in series, but that wasn't the case. I intend on cutting the tabs between the cells so that I have something easy to solder to. The spot welds seem strong enough.

Quote:
Originally Posted by everydayflyer View Post
Yeah, I know. I've seen these photos, that's why I tried to add a few that weren't in the link you posted.

I wouldn't even be trying A123 if it wasn't for all the contributions that you have made. Thank you for taking the time to post the information.

jackerbes, thank you for the link. I glanced over it, but I will read it in detail before building the 3S packs. I plan on two triangular, and two flat.

Quote:
Originally Posted by Sabrejock View Post
And if you don't have a set of security torx's, give the pimple a couple of whacks with a nail set punch and use a regular torx. Tex.
I've been know to do that, but I had the bit, so I might as well use it.

Julez, thanks for the compliment on the photos. I intend on using the tabs, I just need the cells in series.
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Old Mar 17, 2010, 07:03 PM
Jack
USA, ME, Ellsworth
Joined May 2008
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"..I was hoping to find some pairs of cells next to each other in series..."

I got my 18650 cells from B&D VPX packs, those had two cells in series. I have never had a DC9180 pack but I see now that it has the cells grouped differently. So I guess none of the pairs in there are in series? I can't tell from the photos.

But your plan to separate them into singles and solder to the remnants of the tin strips that are the jumpers is a sound plan. Those are tin plated and will tin very easily for soldering.

Jack
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Old Mar 17, 2010, 07:32 PM
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There are some that are in series, but at odd angles.
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Old Mar 18, 2010, 01:13 AM
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As new lipos got so much cheaper(not to mention HK ) and lasts long, why waste time in those old/ heavy/ expensive/ tiny capacity/ less powerful/ high self-discharge/ inconvenient cylindrical shaped A123 cells?
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Last edited by Himalaya; Mar 19, 2010 at 01:40 AM. Reason: add comment
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Old Mar 18, 2010, 07:19 AM
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United States, NJ, Frenchtown
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Because I can run my cells down to 1 volt under load & recharge it at 3C and not have a Fire Department standing by, or throwing them out as being a fire risk.
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Old Mar 18, 2010, 07:41 AM
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Charles Town, WV
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I like using these as 2 cell rx packs for my gas planes.
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Old Mar 18, 2010, 08:00 AM
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United States, UT, Salt Lake City
Joined Oct 2007
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Quote:
Originally Posted by Himalaya View Post
As new lipos got so much cheaper(not to mention HK ) and lasts long, why waste time in those old/ heavy/ expensive/ tiny capacity/ less powerful/ inconvenient cylindrical shaped A123 cells?
You have to recognize that these "old heavy,etc. cells" will do things the Lipos simply can NOT do
As receiver packs these offer a far mor safe sturdy setup-
recharge capability, absence of fire hazard are not trifling matters .
Yes I have latest Lipos in high density etc., - No I won't use them in other than electric power model .
My A123's get used as power supplies for my slot cars (for off track testing) - also for updating of small power tools etc..
All in all, the a123 setups offer more uses than th Lipos . as for price - I saw 2cell rx packs offered in the 2300ma size -all wired with balancers -for 25 dollars US - Can't beat that in that marketplace . I testetd some for a friend - they they arived in balance and and charged to capacitiy as intended.
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Old Mar 18, 2010, 09:27 AM
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USA, AZ, Gilbert
Joined Jan 2006
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Agreed - The best thing about A123 cells now that lipo's have come so far in the past few years is to make RX packs our of these.
I have removed the small 123's from my smaller planes and use lipo's in them now. Needless to say, I have a LOT of RX packs now.

Rick
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Old Mar 18, 2010, 06:23 PM
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California
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Quote:
Originally Posted by Himalaya View Post
As new lipos got so much cheaper(not to mention HK ) and lasts long, why waste time in those old/ heavy/ expensive/ tiny capacity/ less powerful/ inconvenient cylindrical shaped A123 cells?
A123 cells are a lot more durable, 3S packs charge in 15 minutes, and they are good for over a thousand cycles.

http://www.hangtimes.com/a123_batter...iants_faq.html

What is HK?
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Last edited by u.rusty; Mar 21, 2010 at 03:47 PM. Reason: Added link
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