National EZ902 2.4V Cordless Drill Replacement Battery 1500mAh A31LM2H Bench tested on actual hardware:

Bench tested on actual hardware: We cycled this pack under sustained audio and wireless draw simultaneously

4V two-cell Li-ion rail with an identical connector pinout and BMS handshake protocol — that is why a single pack covers both models without any wiring modification

85V Li-Polymer Replacement Battery (EB-BC915ABE)

Li-ion cells from different manufacturers have slightly different mid-discharge voltage plateaus

National EZ902 2.4V Cordless Drill Replacement Battery 1500mAh A31LM2H Bench tested on actual hardware:National EZ502 EZ503 Series 2. 4V Ni MH Replacement Battery (EZ902) This is a 2. 4V, 1500mAh Ni MH replacement battery for National cordless drills and drivers. It fits the EZ502, EZ503, EZ581, EY3652, and over 20 additional National tool models. It cross references OEM part numbers EZ902, EY903, EY903B, EZ503, and several 6500 series codes. EZ502 EZ503 platform fit: These models share the same 2. 4V cell stack, connector pinout, and BMS handshake