The LioN batteries are much tougher and can hold a charge for years without charging. Their capacity is much higher for the same weight and volume.
ALL LioN charger are smart otherwise they are dangerous. Apparently the market for them was held off after a black box blew a jet cockpit apart many years ago.
I bought a Milwaukee 12V LioN drill in the spring with a very slim battery and handle (no bump). It felt awkward at first without the heavy weight at the end of the handle. I got used to it and love it, now. I just used it to finish the decking on my deck. Did some decking support backing framing with deck screws and deck board (5/4). Went though about 25 pounds of 2.5" screws and this little drill performed flawlessly without even a strain. Seciond battery was always charged way ahead of the installed one going dead. The only disadvantage I can see is there is no real notice of battery dying. You get a few hiccups and then full stop. Then you look at the 4 LED meter on the side and only one lights. Battery swap time. Even when it came time to do all the **FILL** screws (I did the ends and middle of each deck board as I cut them) the swap battery was always ready ahead fo the installed one (continuous screwing).
I am really impressed with LioN batteries. It would have killed my 12v Ni-Cad units (and has on previous cases) They are never the same after the hard usage. Bastards won't introduce NiMh batteries for some marketting scheme to keep the users suffering! LOL
NiCads are raed by the manufactures to lose 1% of their charge per day on the shelf. My experience has shown this to be overstated, when new, and as age creeps in, a complete lie. More like 10% per day after a many hard uses and age. Nicads do not like to be stored charged as nickel bridges develop that internally drain their charges off as they get older. NiCads do not lose much capacity in sub-zero weather.
LioN batteries do notlike to completely discharged and mnost usages have circuits to prevent that. Always keep them over half charged for best life. Not sure about cold temperature effects on them.
I doubt you could adapt old drills for usage with LioN. Special charging techniques and temperature monitors are used to avoid explosion, I am told. Nicads just had a 1/10C charge thrown at them or voltage sensing fast charge in the smarter chargers. LioN takes a lot more finesse and complexity.
You need new chucks anyway.
"Paul" wrote in message news: snipped-for-privacy@news1.newsguy.com... I am wanting to get an 18v lithium-ion compact drill, either a Makita or a Bosch. I've used both and like them. I currently have a Makita 12v regular battery, that I used the heck out of on and off until the batteries went and really liked it. My other drill is a Hitachi 18v, regular battery. Never liked the chuck on that one and every time I pull it out, I have to charge the batteries. So my usage is, when I have a project going, I'll use it quite a bit, then it may sit un-used for maybe months. I want to quit fooling with these others and get the lithium-ion, so would this be better for my usage. I may get, or have rebuilt, one of the Bosch's 12 batteries since I liked that drill so much and have it as a second drill. I do have a corded drill also. Thanks.