How to charge a 24v tool battery.
 

I bought a set of 24 volt battery powered tools - drill, saw, jigsaw, and light - from Pep Boys 18 months ago. Allegheny Tools (China). The charger stopped working and neither Pep Boys nor Alltrade Tools (successor to Allegheny) can find me another 24 v charger. Although the battery looks standard (see picture) it will not fit Dewalt, Hitachi, Milwaukee, Ryobi, Ridgid, or anything else.

Any idea what to do? I have it outside hooked up to my 12 volt car battery charger on slow charge but not sure that will work. After one hour I have just a smidge of power in the battery but not much.

Wife threw away the broken charger unfortunately so I cannot even try to get it fixed.

Should I buy a Dewalt 24 v charger and wireclip it to my battery; that should work but is not very elegant.

Appreciate suggestions.

Check out all-battery dot com and look at a universal 24V charger. That should fix you up. You are going to need a 24V source to accomplish the task.

First a 12v will charge it, but will only charge to 12v so it won't have any ummph.

Try and locate a 24v power brick and splice it into the wires to the charger.

I did that with an 18 volt setup for a neighbor, I happen to have a brick available.

Sell the tool set on ebay and replace with Dewalt.:D

24v is a lot, for most applications 18v should be fine. The only time my 18 starts to struggle is when I use it like a hole saw and try to bore 3in holes through multiple studs. That runs the battery's down fast.

TX - all-battery.com does not have a 24 v charger but I sent them an email anyway; thanks for the lead.

KKnudson - what is a power brick? I do not have the old non-working charger; wife threw it away. So I cannot wire the power brick into the charger. Or are you saying connect the power brick into my car battery charger and then to the battery? Not sure what you mean.

A power brick is the power supply for any device, ie the power supply for a laptop is called a "power brick" , because of that big block in the power line or right at the plug itself.
Even those little ones for phones etc are referred to as Bricks.

I should have mentioned you want to find one with roughly matching characteristics, ie output voltage, type (AC/DC) and output wattage, as the original.
Without the original charger base though you are out of luck.
You technically could connect right to the terminals on the battery, but that would be a pain, and many of those charger bases have a shutoff in them, to stop charger when the battery is fully charged.

Power bricks are really just transformers.

I save a selection of them for various purposes, I have replaced some battery packs with bricks when I had a appropriate one. So for my neighbors, I used the brick from an old HP printer I think.

Kknudson - I may just buy a 24v charger and wire it to my battery. Again, not elegant but it should work. Looking on my tools I do not see the amps. However I guess any 24v tool charger would be engineered to provide a reasonably comparable amount of amps. Went to Home Depot and they do not even sell 24v tools or batteries.

By the way I am assuming that the red wire on my automobile battery charger is positive and the black is negative. That's the way I have it hooked to my tool battery and after four hours I have almost zero charge. Just tried it and it spun slowly about twice before it ran out of juice.

If you have a couple of car battery trickle chargers you can put them in series to get 24V. Yes the secondaries are isolated so this is OK. Otherwise a 24V wall wart should be fine. Such as

http://www.mpja.com/prodinfo.asp?number=18344+PD

At 1/2 amp it will take a while but will get the job done.

This might work:

http://cgi.ebay.com/QILI-24V-SCOOTER-AC-DC-POWER-BATTERY-CHARGER-NO-PLUG-/270645633807?pt=Laptop_Adapters_Chargers&hash=item3f03bca30f

Mpolli - I like idea #2. All I need to do is put a clamp on each wire and clamp it to my battery. Might buy that one. However, I assume my battery is a NiMH or NiCD and that the scooter charger is for a lead acid battery. So would the charger you recommended work ok on my nickel battery?

How would I wire two battery charges together in series? Does it require getting into the guts of one of the chargers?

try makita.
the older universal charger should handle it fine.
it also has a fast 1hour charge that monitors the feedback power, and safely rapid charges batteries.

duh... only goes to 18v... hmmmm.... :(

Try batteries plus http://www.batteriesplus.com/
Most of the drill battery chargers, especially the multi-volt ones, will have a full 120v at the contacts when plugged in, so it's not a very good idea to try and use alligator clips with one. They sense the charge by sensing the current going out, with no current they are just on.
What is keeping the battery from just plugging into a main brand charger? If there is a ridge or something, just cut it down so it fits.

Welder - so far I have not found a 24v charger for sale in a brick and mortar store so I cannot try the fit. However the Hitachi's etc charging slot is either too small (need 1"x2") or way too big. There are also different configs for the charging tabs. Mine are pos and neg tabs on right and left and third tab (ground?) at the rear. Some have the ground at the front.

Do not understand you comment about using the wires. If I clip a wire on the pos tab of the universal charger and then clip the wire on the pos tab of my battery - is that different from just making a direct connection battery to charger?

Do you have any idea about the elec scooter charger? If it is built to charge a lead/acid battery for the scooter, can I use it on a nickel battery?

Most of the multi-volt chargers, the ones that are good for 12-18 or 24v, have a warning on them that there is 120v present at the charging terminals when the charger is plugged in. So, it you clip onto the charger with it plugged in, you'll get a decent shock.
Craftsman has a 7.2-24v charger that could probably be modified to work. It may be a bit of a pain since you do not have your old charger though. Maybe advertise on your local Craigslist that you are looking for one, you never know what you may find.

What specifically told you the charger was bad though?

I wouldn't use a lead-acid charger for a Nicad, they really do charge differently.

Actually I think it was my fault. I inserted the battery the wrong way in the charger. It did not fit but it went in. Hours later when I checked it I realized I had inserted the battery the wrong way. After that neither of my batteries would take a charge from the charger so I guessed that I had messed up the charger.

First of all, someone "skilled in the art" might be able to fix your charger. Could just be a blown fuse or burned component. As for your other question about battery types, technically the different chemistries have different charging profiles, however they all need more than their nominal voltage to charge, and as long as your power supply is not too big compared to the batteries, it should be fine. For example, Black and Decker sells a charger for both their NiCd and Lithium Ion VersaPak batteries (silver and gold) and it is nothing but an unregulated DC power supply. The transformer loads down, since it is small, and that prevents over charging. They charge their 3.3V batteries up to about 4.3V. So that is why a cheap unregulated wall wart supply is a good solution. It will float up to around 28V which is what you want. But if it really was me I would just fix it since that is what I do.