Ni Cad battery packs to Ni-MH

[Ed446]

I have Ni Cad 18 volt battery packs for Black & Decker yard tools, weed eater, blower, etc. If I have these packs rebuilt using Ni-MH batteries, can the same charger be used that charges the Ni Cads?
Thanks
Edwin
P S Where is a good place to get these rebuilt? I asked one place that rebuilds these packs about the charger and they didn't know.

[dacflyer]

call and ask a hobby shop, they are big into using all sorts of batteries, especially nickels
i am sure they can enlighten you..

as for rebuilding them, try "Batteries PLUS+" if there is one in your area..

[sghioto]

I think you can but it may take twice as long to charge.
If I remember correctly the NIMH are charged at about twice the current of a standard NI-CAD.
Shouldn't damage anything if it doesn't work.

Steve G

[ringo47stars]

I have not seen a charger that works for both types without switching from ni-cad to ni-mh and that type of charger doesn't usually come with power tool batteries. Putting ni-mh ones in the ni-cad charger would damage the battery. You are better off buying a ni-mh battery and charger for your power tool.

[gerty]

I had them rebuild an old 12v cordless drill battery.
http://www.primecell.com/nimhconv.htm

The conversion went from ni-cad to ni-mh. I used the drill (Makita) for roughly 3 more years, untill it committed suicide by jumping off a 6' stepladder. I used the original ni-cad charger.

[Rodney]

NiMh and NiCad are very similar in how they can be charged. The same charger can be used on either one; just, if peak detecting chargers are used, set the trip point for NiMh at about 5 millivolts while the NiCad can use about 10 millivolts. Now, if slow charging (being defined as charging at 0.1C) you can charge either type for 15 to 16 hours at 0.1C and expect a full charge. At that low rate you will not damage the battery by overcharging it. Here are some good sources of info if you really want the straight dope on batteries:
http://www.hangtimes.com/redsbatteryclinic.html
http://www.camlight.com/techinfo/techtips.html
http://www.whenshtf.com/showthread.php?t=2153
http://www.srbatteries.com/nimh.htm
http://dansdata.com/gz011.htm
http://users.frii.com/dlc/battery.htm

[Ed446]

Thanks everyone. I sent 3 18 volts Black & Decker packs to Prime Cell in PA.
I went with the high capacity ni-cads due to being less costly. Got them back this morning.
Cost was $156.00 including return shipping. Put one of them in a blower and it was ready to go.
Thanks again
Edwin

[Lenp]

Side Note:
MagLite has a rechargeable unit that was NiCad powered for years. They switched to NiMh a few years ago with no compatibility issues on their chargers. As a Maglite service center I see almost no charger failures and batteries with code dates 3-5 years old still going strong.
Len