Hi All,
I have several old Makita 9.6v cordless drills that take the “stick” type batteries. I also have a few chargers for them. All were purchased back in the 80’s. When they were new, they all came with Ni Cad batteries. As expected, all of the batteries are now shot. I see that they now make replacement Nickel Metal Hydride batteries of the same stick type and was wondering if I need to get a new charger for this battery.
Anyone try this? I really don’t want to plunk down the $$$ for the NiMh batteries only to find out I need new chargers. In that case, I’ll just get some cheaper replacement Ni Cads.
Interestingly enough, I contacted Makita directly and they could not answer this question because their phone support database has not been in service long enough to answer technical questions about tools that old.
Replies
Here's a site with both theoretical and practical info:
http://www.angelfire.com/electronic/hayles/charge1.html
-- J.S.
NiCd and NiMH are one of the few mixes you can get away with, although I have not reverse engineered any vintage Makita charger to know what algorithm they used Any C/10 charger will work equally well for NiMH or NiCd IF you dont forget to take it of charger after 1-16 hours. Note the big if, which decreases life on either cell.
a 1 minute web search gave the following which is faster than me typing more.
http://www.houseofbatteries.com/librarydetail.asp?articleid=10
PS: dont never ever put over 4.1 v per cell on a Li-ion in any kind of charger or it is soon toast.
Edit PS: If I'da know John already did a web search for you, Ida never bothered <G>
I do some occasional spacecraft power consulting work, and the battery experts in that field would NOT EVEN CONSIDER using the same charger for even different mfgs of the same cell chemistry, but out there, lifetime is everything! BTW, LI-ion rules now, if you really want to get an inclination of how complex battery chargers can be, tear down an old Dell laptop Li-ion battery pack!
Edited 1/6/2005 7:00 pm ET by JUNKHOUND
Thanks to both Junkhound and John for this info. The few minutes of googling I did only returned links back to Amazon and ebay and the like. Should have left "Makita" out of the search string.
Hey, Rat-
I have been in the same Makita posistion as you. The older chargers will not accept the newer NiMh batteries. Coupla new batteries = $60-$80, new charger $30-$40, soooooooo............................. you can see that a logical choice would be to just buy a new 9.6v drill kit for almost the same amout of money. You likely can find one for $100-$130. That's what I did.
Ken Hill