Author Topic: help rebuilding cordless drill batteries (Read 4466 times)

divemaster1963 · « **on:** May 31, 2009, 04:38:18 AM »

I"ve been given some battery pack by a very generous person on this site. I'v having a small problem. I don't have a tab welder to weld new tabs to the batteries to rebuild my drill. I'v thought of possible using a ark welder using copper electrods to tap the weld the tabs. but want to get a consenious form the forum on possible other ways to do this procedure?

any and all sugestions would be deeply apreciated.

divemaster1963

bob g · « **Reply #1 on:** May 30, 2009, 11:27:03 PM »

do a search on here, if i recall correctly there was someone here that built a

welder with a timed spot weld function, big caps and some other stuff, and from what was reported it worked very well.

might have been ghurd, i just don't remember

bob g

spinningmagnets · « **Reply #2 on:** May 31, 2009, 12:27:05 AM »

Here's a thread about building a home-made battery tab spot-welder to custom build electric-bike packs from DeWalt/Milwaukee cordless drill packs. Might be some useful info for you.

http://endless-sphere.com/forums/viewtopic.php?f=2&t=2633

richhagen · « **Reply #3 on:** May 31, 2009, 01:57:51 AM »

I'm pretty sure it was Dinges who built it. It was a nice unit. Rich

richhagen · « **Reply #4 on:** May 31, 2009, 02:01:33 AM »

Here was the story, but his user files are all gone but one, so the pictures are no more. Rich

http://www.fieldlines.com/story/2008/2/26/15327/2668

Norm · « **Reply #5 on:** May 31, 2009, 04:55:10 AM »

Save yourself the trouble...the older packs have

tabs that are already welded to the battery....

leave them..just cut the tabs halfway, when you have them in their new position solder short

little pieces of bare 12 guage copper wire to

bridgefrom the cut end of one tab to the other

use good grade of electrical solder and PASTE FLUX the secret to quick and easy soldering for

me it was anyway.

Eager to help any questions about it ask away

I'll try to help....

zap · « **Reply #6 on:** May 31, 2009, 07:54:29 AM »

I'll second Norm's soldering statement. Unless you really want to build a spot welder, the soldering works well enough.

You can also use thin gauge steel from tin cans cut into strips. Like the bottoms from hot chocolate containers.

Tinbendr · « **Reply #7 on:** May 31, 2009, 09:56:35 AM »

I did that here.

Norm is right, just order batteries with tabs, then solder the tabs together.

JW Peters · « **Reply #8 on:** May 31, 2009, 10:47:01 AM »

Before you cut them apart check to see what individual cells are producing zero voltage. Then give them a jolt with 6 volts. Not more than 6 volts. I use a 6 volt lantern battery. You can also stack four or five cells together to get 6 volts to use to jolt the bad cell. Read this. JP http://wiki.answers.com/Q/How_do_you_repair_a_NiCad_battery

hydrosun · « **Reply #9 on:** May 31, 2009, 01:47:36 PM »

I took apart some drill battery packs and found out which cells were bad. I was able to take good ones out of one pack to replace the bad ones in the second pack. I broke off the tabs as close to the bad cell as possible to give a long tab on the good cell. To put them back together I broke off a piece of solder , put it on the sanded cell surface, put the tab on top of that and then applied and held the tip of the largest soldering iron I have,(maybe 100 watts). It took less than 5 seconds. The connections seem to be sound. Sanding the cell surface and enough quick heat worked for me.

Chris

divemaster1963 · « **Reply #10 on:** May 31, 2009, 04:01:12 PM »

Hey thanks for all the info.:-} I not quite in the mind set to build the spot welder. time and money are a factor. I like the idea of soldering the tabs. did not think about leaving the tabs a little long to solder on. I'll post some pics and story line on assb. them together. may be a little will thought. honey do list got real long during the three weeks of steady rain we had. some days had 4in. of rain in as little as 2 hours. grass got so tall we could not see our 120 lab in the back yard. I cant cut more tha a 100x100 section of the yard at a time. have to cut it 3 times to get it cut right. have over 3 ac. of grass to cut.

thanks again

divemaster1963

Bruce S · « **Reply #11 on:** June 02, 2009, 11:06:24 AM »

divemaster1963;

I agree with Norm et-al, cut the batt taps 1/2 why between each other, use a paint brush and thinly spread of rosin paste on each end, good thin solder and a HOT 25watt pencil iron.

I would suggest a spring loaded clamp to hold the together ( I use small binder clips) 'cause they're gonna get real hot real fast.

Done this way is good as you can get, and money saved for welder

I know what the grass looks like, had to take the weed wacker to the stuff just to bet mower out there :_)

Have fun!!

Bruce S

Bruce S · « **Reply #12 on:** June 02, 2009, 11:18:55 AM »

Divemaster1963;

IF you've already pulled the TABs off, it would be best not to try to solder directly to the batts, as they could get too hot.

If there's any of the tin still on the batt ends you can safely solder to those.

Bruce S

divemaster1963 · « **Reply #13 on:** June 02, 2009, 08:30:58 PM »

hey bruce thanks for the idea. have gotten most of the yard cut. now it's supposed to rain again wed- fri. It's a never ending they say possible of 2-3 inches. but the wind is suppose to be in the 15-25 mph zone. good for the ecm. got 6 new gem gel cell batteries from a battery distributer. all had 12.85 volts cold. their gel cell to. got lucky again. city south of here was changing out their meter maid cars batteries. they had no fualt to them. were only 2 years old.:-)

hope your wether is better

divemaster1963

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