I recently purchased a Dewalt DCL050 light and while reading reviews there seemed to be a lot of questions about current draw / battery life. Dewalt claim a maximum of 22 hours but that’s about all I could find in official documentation so I thought I’d attach it to a lab power supply and measure what it actually draws. I had the PSU set to 18V which is the nominal voltage and results were as follows:
Low setting (250 lumens) = 240 mA
High setting (500 lumens) = 460 mA
With the low setting the instantaneous current draw skips around because of the PWM used to dim the LEDs so the above is a 10 second average. The largest Dewalt battery is 5 Ah and 5 / .24 = 20.8 so the 22 hour maximum sounds plausible given that batteries are normally rated for a 10 hour discharge and often perform a little better at lower discharge rates. Here’s a little table of roughly what it would be for the common battery capacities that I know of:
Capacity (Ah) Low setting High setting 1.3 5 hrs 3 hrs 2 8 hrs 4 hrs 3 13 hrs 7 hrs 4 17 hrs 9 hrs 5 21 hrs 11 hrs 6 25 hrs 13 hrs