Need help in rebuilding battery packs

I'm looking to rebuild a couple of Dewalt 14.4V NiCad packs. Where can I get some good info on doing this? I would also like to get whatever piece of equipment is used to "tack" the cells together as well. Would the cells in this application have to be "matched"?

Alternately, can anyone recommend a good source for having the packs rebuilt with some good quality cells? I'd still be interested in the "welder" and sources for related supplies. It seems like I always have some sort of rechargeable pack that needs to be renewed. Any and all information is appreciated. /ubbthreads/images/graemlins/smile.gif


Peter

i get brass strip from the hobby shop and solder them.
tin all parts and sweat them together.use a high wattage iron and work fast.
batterystation has the sanyo 2.4 nicd on his site.
btw most tool packs use sub c's
the sanyo or panasonics are the best for this abusive service.

Battery Station can make the packs, too. Give Kevin a call and he'll tell you what welder to use.

I don't recommend soldering. If you do get it too hot (positive end) and melt the porous membrane that's designed to vent gases, you've ruined the cell and it could be dangerous. But a lot of people do it and without problems.

Hi there,

I highly recommend purchasing the sub C cells 'with tabs'.
The tabs are already welded to the cell and it's ok
to solder the tabs together. Of course you want to make
sure your pack uses these sub C size cells first.

They are available on the web, do a search.
They sell various qualities noted by their Ampere hour
rating -- the higher the better.

Take care,
Al

[ QUOTE ]
MrAl said:
Hi there,

I highly recommend purchasing the sub C cells 'with tabs'.
The tabs are already welded to the cell and it's ok
to solder the tabs together. Of course you want to make
sure your pack uses these sub C size cells first.

They are available on the web, do a search.
They sell various qualities noted by their Ampere hour
rating -- the higher the better.

Take care,
Al

[/ QUOTE ]
in power tools the very thin tabs on most cells have too much resistance.and high capacity cells are not the best due to internal resistance being high.
my 14.4 makita drill draws over 30 amps near stall.
tried 3300 nimh but they lose their punch very early in the cycle.best compromise has been the sanyo or panasonic 2400 NICD.
and the trick to safely soldering is to use a hot high wattage iron and work fast.never ruined a cell soldering them.

Thanks for the responses guys. I would still prefer to acquire the tack welder and use that instead of soldering the cells, provided it isn't prohibitively expensive. I have emailed Kevin at BS for some guidance.


Peter

bringing up the dead with the search on this one....

I have the same problem too and need to replace the packs on my porter cable 12v drill. I opened them up and noticed that they say Sanyo Ni-Cd 1.9Ah DF. would going upto a 2.2Ah battery be a problem for the charger? Also did you find any info on the tack welder you were looking into? The cells are sub-C by the way.

There's a post on higher capacity cells vs lower capacity cells. I think it's about internal resistance of the newer cells. If your charger is dumb you should be ok but the charging period will be a bit longer than normal.

Your right on the tabs. Some cells leaks if you solder them. Go Ni-Cd, they give out more amps.

I have a cheapo local brand 12v cordless drill, it's around ~$USD14 after conversion. If the battery pack dies, I doubt anyone will be rebuilding it. At that price, it's cheaper to get a new set. It hasn't died on me yet, I am not a heavy user, I use my useful hobby charger to charge it, the charging cradle that came with it is way too dumb.

The local interstate battery will rebuild packs. The tack welder they have does NOT look cheap.

There is nothing wrong with soldering. I have seen "gorillas" do this for decades in the r/c car segment.

Matched cells would be a big plus. If you'll pay the shipping, I can give you the specs on your loose cells. But shipping them all over the country will eat up your savings.

Check ebay for replacement battery packs.

Also, the tabs on the cells are fine. They do allow for some movement of the cells. 30A stall may be correct, but much of that and you'll be buying a new drill anyway.

[ QUOTE ]
LitFuse said:
I'm looking to rebuild a couple of Dewalt 14.4V NiCad packs. Where can I get some good info on doing this?

peter

[/ QUOTE ]

primecell.com

I have to replace the batteries on my isotip soldering irons, they both use nicd subC's, one charges in 1 hour the other in 3 hours... I wonder if it would be possible to just replace the batteries with nimh instead. I dont think the iron needs as high a current that nicads are preferred for I just want longer runtime and be able to top them off now and then. Anyone know if a nicad charger would work ok with nimh cells, expecially these fast chargers on isotip irons?

One possible idea for cheap nicads is harbor freight has sales on batterie for their drills I know one of them for sure uses subCs and about 12 of them. The pack is I think 15.00 and I think it was on sale for 10.00. May be a cheaper way if you can manage reconnection them.

Lynx, your NiCad charger will quickly destroy NiMH cells. If you charge them on a NiMH charger, they would probably be OK as long as your iron doesn't draw more than about 3 amps (or you buy high discharge rated subCs). I say that because a lot of subCs are for razors or such, not the high rates from a drill which are mostly still NiCad because it can take more abuse. It sounds like your isotip iron is using removable cells. I have an older one with soldered in batteries.

As far as disassembling a drill battery pack for the subCs, I do that frequently. You can find two together in the proper orientation and seperate them with the tabs to solder to. I usually pry the connecting tabs off with needle nose pliers since I'm normally pulling good cells from battery packs with dead cells. But if all the cells are good, you can cut the tabs in half and still have enough to solder to.

you need 2 sub c cells per isotip.
the standard ones are easy to reload but you have to be carefull with the 60 minute ones.they terminate charging via thermal sensor on the neg end of 1 cell.
after reconnecting the - end by soldering to the side of the cell i sand the thermal sensor and - end and apply a bit of jbweld to make the thermal path.
i have 3 of the red 60's and 7 of the others and i paid an average of 1.50 each.
of course i had to rebattery all of em /ubbthreads/images/graemlins/smile.gif

[ QUOTE ]
Lynx_Arc said:
I have to replace the batteries on my isotip soldering irons, they both use nicd subC's, one charges in 1 hour the other in 3 hours... I wonder if it would be possible to just replace the batteries with nimh instead. I dont think the iron needs as high a current that nicads are preferred for I just want longer runtime and be able to top them off now and then. Anyone know if a nicad charger would work ok with nimh cells, expecially these fast chargers on isotip irons?

One possible idea for cheap nicads is harbor freight has sales on batterie for their drills I know one of them for sure uses subCs and about 12 of them. The pack is I think 15.00 and I think it was on sale for 10.00. May be a cheaper way if you can manage reconnection them.

[/ QUOTE ]

My isotip irons have subC cells that are soldered in place,
at least the 3 hour one does I haven't taken apart the 60 min one but I figure it does also. one thing I have thought of is an external subC battery pack and a clip to hook onto the bottom of the iron to recharge/run it off of when it dies in use. I could use nimh that way and make either a seperate charger or use a standard charger and battery holder of some sort.