Charger for battery powered tools

[Junior437t]

I have an 18 volt Black and Decker set of tools. Drill, Circular saw and recip saw. I  use them quite a bit and sometimes forget to charge all the batteries. I have looked at the B&D website and they don't show a 12 volt chatget that I could hook up on my truck. I hooked up a small inverter to my truck battery and plugged the B&D charger in. The B&D charger hummed pretty loud so I unplugged it thinking it might not be a good situation. What I am looking for is an idea as to how I can charge the 18 volt battery with my 12 volt truck system. The B&D slow charger has a transformer at the end of the cord where it plugs into the wall. It lists it's output at 21.75v dc==210ma. It say input is 120vac~60hz  18w. At the other end of the cord is just the battery holder with contacts. It seems to me like I should be able to cut the cord off and put a cigarette lighter end on it to plug it in. My question is, How can I convert the 12 from the truck to 18 volt for the battery? Maybe some electronic components that I can pick up a Radio Shack? Thanks

[james]

to use a inverter on a lot of re-chargers you need a true-signwave inverter to keep from blowing the transformer a 50  or 100 watt should do you id be carefull of trying to modify the charger cord  those batterys can fail or explode if incorectly charged
check out backwoodssolar.com
james

[Jason_WI]

Most laptop car chargers output 18 to 19 Volts and plug into the cars 12 volt system. You will need some way to regulate the current as the laptop output is usually 2 or 3 amps.

The reason for the humming from the transformer is because most inverters use a modified sine wave that resembles a stepped square wave. Those steps are causing the windings to vibrate in the transformer.

Black and decker batteries should charge in a Dewalt 18V charger. B&D owns Dewalt. Look for a Dewalt car charger would be your easiest option.

There are curcuits that I could post here but without electronics experience you will most likely end up with smoke and cooked batteries......

Jason

[DanG]

When I was with the phone co. I had a regular old cheapie inverter in the truck.  I charged everything with it.  Tools were mostly Makita and Milwaukee.  Also cellphone, laptop, and a whole array of test gear.  Never had a problem with any of them.

[Tom]

I know why, DanG.

Junior was concerned when he heard the noise coming from the charger.  He's a younger fellow.

Your hearing is bad.  It comes with age.  I know you're old 'cause you have great grandchildren.

Ignorance is bliss.    :D :D

[DanG]

 eh?  Could ya type a little louder please?  Am I gonna hafta put on my glasses to hear you? :D :D

BTW, my chargers didn't make any noise, I'm quite sure!

[SwampDonkey]

I use an invertor for 300 W in the truck and if it draws too much it will give a warning signal and red light. I think it was $30 at Canadina Tire. They have 1200 watt ones also.

Dang, all ya gotta do is remember to wipe the crusties from yer eye lids when ya get up at 4:00 am to check the oil in the mill's drive motor for the upcoming day. ;)

[DanG]

There's s'posed ta be oil in there? ???

[SwampDonkey]

Well if it's run this long, I wouldn't worry none. ;D

[Furby]

I use a 400 amp inverter, and will someday get a 1500 amp setup with batts and everything, but for now the 400 does it. It's nice being able to dry your boots while on the road and stuff like that. ;)

[SwampDonkey]

 :D ;) Turn the heater dial in the pickup.  ;D

[Furby]

Tried that, it takes too long! :
I have a pair of those boot dryers, and they are NICE! Don't take up much room and can have dry boots without wrinkled feet! ;D

[SwampDonkey]

 :D Yer suppose to stay in the dry cab of the pickup in them down poors. ;)

[caryr]

I use a 400 amp inverter, and will someday get a 1500 amp setup with batts and everything, but for now the 400 does it. It's nice being able to dry your boots while on the road and stuff like that. ;)

I think those should be watts not amps! 1500A would power a house/shop.

As far as the original problem goes. As mentioned a true sine wave should solve the problem. You could also get a line filter to help remove the HF garbage. I would definitely not try messing with the cords unless you know exactly what you are doing. Battery charging can be an art. It may be as simple as a certain voltage at a certain current for an older battery, but it certainly isn't that simple for the new ones.

Cary

[Furby]

Yup, messed that one up.
Did mean watts, thanks!

[ADfields]

The charger body is MUCH more then just a set of contacts.   After I Melted 2 B&D 12 volt bat's by just cutting off the transformer and hooking the ends to a car bat I opened it up to find a chip and all kinds of little stuff. :   So if I could not charge a 12 volt From a 12 volt with out B&D's $40 12 volt charger you will find it a bit ruff!
Andy

[dansaylor]

try looking on the dewalt site they are industrial black and decker company and they used to sell vehicle chargers for there drill batteries and the batteries should fit either brand charger