I’m currently replacing a Makita 14.4 that was recently stolen.
What’s the story with NIMH vs. NICAD battery systems. If I’m correct, NIMH has more juice, works better in the cold and has not batter memory affect.
Makita offers the 14.4 in both the NIMH and NICAD version. My previous one was the “red” nicad version. I do remember reading an article on the battery types and there was a disadvantage to the NIMH batteries….anyone know what the is.
Replies
For one thing, it has a shorter lifetime. Memory has been reduced if not eliminated by "smart" chargers that are sold with the upper end cordless tools. I have a 12v NIMH and NiCAD batteries for my Makita and I don't think the running time is any different. In fact there have been occasions when I think the NiCAD lasted longer.
someone gave me a 12v NIMH makita. The battery won't work in a Nicad charger, tried to bridge the contacts with foil tape, still woodn't work. had to buy a charger that does both,cant comment on longetivity, about the same.
no turn left unstoned
According to Gary Katz in Understanding Cordless-Tool Batteries, FHB #128, pp 108-109, NiMH batteries have both a shorter run time and a shorter life. But they're more expensive, too.
Also, forget the idea that batteries have memories - They don't, and haven't for years. Also, never fully discharge any cordless-tool battery. Doing so can cause internal shorts which greatly reduces the battery's life. Run 'em until you notice a power loss, then recharge.Andy Engel, Forum moderator
Please be sure to dispose of those NiCAD batteries properly. Recycling is prefered. Radio Shacks usually have a drop box intended to be recycled. Cadmium is nasty stuff when it gets loose. It makes many commecial poisons look positively huggable.
NiMH in comparison is benign.
Edit for spelling. 06/13/02
Edited 6/13/2002 10:41:14 PM ET by 4LORN1
That's a good point, 4lorn1. The chief advantage that NiMH offers is much lower toxicity than NiCd.Andy Engel, Forum moderator
I just wanna chime in as an owner of 12-V and 18-V tools.
They are the "yellow" tools with the XR pack nicads.
Dispite warnings about not draining the batteries all the way, I've been using the weakened batteries in the matching flashlights to drain them further. Also, the flashlights have been very useful in countless situations with fully charged batteries. Maybe more useful then the tools.
The two 12-V batteries that came with the drill are still going strong without any noticeable shortening of runtime. The 12-V outfit was bought January, 1995.
The 18-V batteries are about 4 years old.
However, I am not in the trade and the tools don't see as much action as it would at a job site.
Alan
Overall life of the NIMA is less. It is more expensive. There's a reason many manufacturers haven't come out with them yet. speculation that some may already be looking ahead to the next generation.
With both types, heat is the destroyer so deep cycle discharge hurts them as does superfast recharging. The old slow chargers were actually kinder to the batteries. The memory capacity thing is mostly a myth. The best way to get good service out of your batteries is to avoid overheating and not worry about which kind they sell you.
But who needs all these newfangled devices anyway, I still like clinbing up on the stepladder with my old lead acid car battery wired up to my "cordless" drill...
;>)
> I still like clinbing up on the stepladder with my old lead acid car battery ....
Not so funny, the gelled version of lead acid batteries are used quite commonly to run motion picture cameras. Of course not for hand held use, they're in anvil cases. Sealed lead acid seems to be more for larger loads.
-- J.S.
Be careful about discharging the batteries all the way. NiCAD cells will often flip polarities when taken too low. As with all things the individual cells in a pack are not equally strong. When the weakest gets weak enough the stronger will try to recharge it. The cells being hooked up in series makes this charging happen in reverse and flipping the weak cell. This ruins the pack and sounds a lot like prison.
I'm not sure if NIMH are subject to the same problem. I suspect they are. The manufacturers say to run the device until a major drop in performance is noted and then recharge.