Tempting. I’m hoping that the version with the built-in usb-c cord makes an appearance. If not. The ability to go back and purchase previous offerings might prove useful. I have no complaints about my familys Mophie products.
@ergomeh The cells in power banks are typically optimized for energy density at the expense of power density. If you draw less than 5 amps, you are probably fine. Try to draw more than 25 amps for more than a minute and the cells will probably puff up like little balloons.
So these will work fine for some tools, but not for others.
5 amp hour Cells that can handle being discharged at 100 amps have more metal in the anode and cathode, and a bunch of other differences that make them heavier and more expensive than 5 amp hour cells that can only put out 5 amps.
Puffing up like a balloon is the preferred way for lithium batteries to fail. Shooting out jets of flame is bad. Going off like a pipe bomb is very bad. It is important to make the case such that the batteries can expand if they die.
I bought a 30A BMS and an RC pack (2500mAh). When fully charged the motor start on a drill will pull more than 30A, but running 30A seems to be sufficient (haven’t tried the weed-wacker, reciprocating saw, but does work with the circular saw). They’d definitely need to be strapped to prevent expansion (and get them in the old battery holder). It’s potentially a fun little project, but I later found 5AH Lithium full replacement batteries are around $60. Along with the other problems you describe, these packs, even though new, may have been sitting around for a while and discharged.