If you’re going to purchase a cordless tool, then you should really think about getting one with Lithium ion batteries. They cost more, and it’s easy to think you could just buy a cheaper model and get a spare battery, but it’s not the same. Craftsman power tool battery are a true hassle free solution.
Lithium ion batteries, or Li-ion as there often called, have got a lot going for them when you use them in cordless tools. They have twice the power density than other rechargeable types, so you get a smaller lighter tool. It’s not just the power density that makes them smaller, each Li-ion cell has three times the voltage of an ordinary cell so it only takes a third of the cells to get same output voltage.
Li-ion cells have a good peak output current and low source resistance. When you overload the tool, the voltage stays up, and they just keep pumping current into the motor. Power tools have thermal overload trips in the motors, and that’s a good thing with Li-ion batteries, if they didn’t they’d just burn the motor out!
And charging is the best thing about Li-ion batteries, there’s absolutely no memory effect. And they charge quickly. Battery manufacturers always like to say they’ve reduced the memory effect, or even ‘virtually eliminated’ it. But it’s never true, you might get away with charging the Black & Decker cordless drill battery from half full every now and again, but if you keep topping them up then the capacity always goes down. With Li-ion they don’t need to reduce the memory effect, there isn’t one.
I use a Makita 18 volt drill with Li-ion batteries. It’s a bit smaller and and lighter than ordinary 18V cordless drills, but it’s as powerful as the best NiMh battery drill, and makes NiCad ones seem like toys. But it does twice the work of other drills between charges.
Li-ion batteries can be topped up whenever you want, and you can start using them again even if they haven’t had time to fully charge. Use the tool all morning, put the battery to charge over lunch, use it again all afternoon. You never have to stop work to go and change the battery.
Li-ion batteries have a low self discharge rate as well, that means the battery stays charged longer when you’re not using it.I also have a Milwaukee Sawzall with Li-ion batteries. For some jobs I’ll be using it all day, and put it to charge at night. But a lot of time I’m just using it for the odd cut here and there, and I just don’t bother charging it. It never discharges itself, I don’t think that saw battery has ever been flat, but I only ever charge it for the big jobs.
Next time you get half an hour into a job, and your old battery for Cordless Drill Driver runs out of juice again, think about getting your next cordless drill with Lithium ion batteries!