Drill machine, replacing battery with stationary supply

[tinitus]

Anyone ever tried to make a power supply to replace a worn battery

I hate to throw out a perfectly good tool just because a new battery is too expencive
Around here its cheaper to buy a new machine

[Richard Ellis]

Please more specific....are you talking about those portable, rechargable 7.2, 18.0 etc. volt type drills??
If so...I had one that wouldn't hold a charge...so I just left off the 'battery pack & put some spade connectors on a piece of zip-cord with some polarized alligators.& away you go. Tapping off a car battery (Car work) or a SLA battery(7.2AH) I have kicking around (Makes a great lantern with a "foglight") My drill in question was a 7.2 V version & it loves 12V (Or less).

__________________________________________________ _Rick....

[theAnonymous1]

Tinitus, why not rebuild the pack yourself? They usually contain standard size ni-cad cells that can be bought individually.

I will be rebuilding some laptop batteries on Monday. I managed to snag some 11.1V li-ion battery packs (for a different model laptop) on ebay for $1.99 each. They each contain 6x 18650 cells that would cost me about $3.25 each if I bought them separately.

[tinitus]

Originally Posted by theAnonymous1

Tinitus, why not rebuild the pack yourself? They usually contain standard size ni-cad cells that can be bought individually.

Richard, yes, the portable ones

Anonymous
Thats exactly what was on my mind, right after posting

So, the battery casing is just an "empty shell", with a "standard" battery inside
Thats interesting


Just to give it some perspective
Around her, replacing a good hand tool battery could cost maybe 100-150USD

[MJL21193]

Originally Posted by tinitus

Anyone ever tried to make a power supply to replace a worn battery

I have been meaning to do just that.
I have an 18V DeWalt that I don't have any good batteries for anymore that I want to use.
Supply: You need some good current from the supply to equal the ooomph of a battery - I have the transformer from a car battery charger. Rectify that with a FWB and 10000uF cap for smoothing should be A-OK.
There are some real upsides to this. First, obviously no charging the battery. Second is it is pretty much fixed in one place, as in hard to take somewhere else and forget about. It'll be where I often need to use such a tool and always be right there.

[MJL21193]

Originally Posted by tinitus

So, the battery casing is just an "empty shell", with a "standard" battery inside

The cells are usually of a different size than standard and they are connected together with strips of metal that are spot welded on. It's a big deal to re-cell a battery pack for a drill and you'll want to make absolutely sure the cells are in excellent shape. One bad cell kills the battery.

Lithium ion batteries have a relatively short lifespan and will conk regardless of whether they have been used or not. Keeping them cool will greatly increase their lifespan.

I've taken apart a few different packs - DeWalt NiCad has cells that are close in size to C-cells. Makita LiIon look like AA but are much longer and thicker:

Picture 1102.jpg

[Richard Ellis]

Yes of course the 'casing' is an empty shell...Didn't know? Oh well.
The "batteries" are standard size type, D,C, AA.
The batteries usually have the polarities soldered with a small metal tab, in a pack, sometimes taped up. You can tell as the dimensions & voltages give it away as to what size batteries are contained inside.
The reverse is possible too....I had a 'portable' phone that was dead but the batteries in the handset were OK....three AA, NiCads'.
Did you know a 9V battery has a set of Quad As' inside???I have a "Streamlight" skinny LED pencil-lamp, takes AAAA inside...a single nine volt will get you replacements as AAAAs' are rare as hensteeth.

__________________________________________________ ______Rick....

[theAnonymous1]

I'm trying to put together a "capacitive discharge" battery tab welder right now.

It's a pretty straightforward device....... all you need is a large capacitor bank (>0.5F), a power supply, a SCR to dump the current, and some pointed copper rods for the electrodes.

[Enzo]

I just buy the batteries with tabs already in place. Digikey, for example has a wide selection of batteries. Batteries come in a variety of shapes, and with or without solder tabs.

[dangus]

I was too cheap to buy a new battery for the yard sale Makita drill, but I wanted a driver drill for screwing together speaker cabinets. So... I found a scrap of MDF that was roughly the size of a battery pack, split some zip cord and taped it to the MDF with the bared ends spread out where the battery terminals would be. Later, I took the terminals from an old battery, soldered zip cord to them, and glued them up into an old battery shell. That was more reliable than the MDF and tape arrangement.

I've generally used a 12V gel cell to run it, or the battery of my truck. The two extra volts doesn't seem to hurt the 9.6V drill any.

I've never measured the current, but I suspect it would take an inconveniently large linear supply to do any useful work. A PC supply looks ideal, since they can often supply over 10 amps at 12V, don't weigh much, and cost nothing if rescued from an obsolete computer.