Hans

I went back to the innernets and found some data sheets for 18650 cells. I misinterpreted some earlier information about discharge rates. It turns out that the batteries used in power tools typically can discharge up to 10 amps, not the 1 X capacity I had thought. That's plenty for my tool, and it should last at least 20 minutes at a 4A discharge. I'll use it on a small grinder for sharpenenig ski edges. Twenty minutes is more than enough run time, and the small size doesn't change the weight or balance of the tool too much. Thanks for everyone's interest. hans

I'm not concerned about run time. I'm trying to eliminate all the power cord wrangling that is more time consuming than actually working with the tool. My drill has adequate run time (for me) with that little battery, and I'm really surprised that the grinder has a higher power requirement than the drill. It's gonna be a lot harder to attach a bigger battery to the grinder too. hans

I want to use a Black & Decker 20V Max battery to power a small grinder I have, but I can't determine the maximum current the battery will produce reliably. The grinder DC motor is rated at 4 amps at 18 volts. Can I safely pull 4 amps from the 20v Max battery? I haven't opened up the battery paack yet, but I'm sure it has 5 x 18650 cells inside. Those are rated for 3.6 Ah, but the battery pack is only 1.5 Ah. Why would the battery pack be rated so much lower than the individual cells? 18650 will do almost 4 amps, so 5 in series should be enough for occasional use of my grinder. TIA hans