1.5V is a nominal voltage. Depending on the history of the cell the actual voltage may vary. The Ahs are the nominal capacity of the battery, i. e. a nominal current can be drawn for a nominal time. With more cells in the adapter a higher current can be drawn. It can also reduce the drop in voltage under load and result in a higher actual capacity. The drawback with parallel multicell adapters is the possibility of currents flowing between the cells when the cells have different voltages.

Check the 1D Flashlight Kit by Maratac. The flashlight comes with a 4xAA to D-cell converter (battery holder). Using four Eneloop cells you’d get 8800 mAh.


One of my D-cell rechargeable batteries is rated at 10,000 mAh, so the four AA’s aren’t quite a match, but have you ever recharged an 10,000 mAh D-cell? You can recharge four AA Eneloops much faster than a single D-cell — four charging ports versus one... if your battery charger can even accommodate D-cell batteries and has the ability to pack 10,000 mAh through one charging port.

Bottom line is that if you want to use D-cell lights and prefer rechargeable batteries, get the adapters. I didn’t do the math ahead of time and bought the D-cell rechargeable batteries which it turned out I couldn’t fully charge because the only charger I had that could accommodate D-cell batteries didn’t have the electronics to reach 10,000 mAh capacity. So I bought an EBL charger that was spec’d for it... I’d have been way better off with the adapters and more AA Eneloops.

Unfortunately, the 4xAA battery holder is not marketed separately, so the 3xAA converters available on Amazon and at Battery Junction seem to be the best option.

Great info, thanks!

before trying a couple of brands of commercial AA>D adapters, I built a couple DIY, using a couple of brass washers (dimpled on the (-) end to contact the flat ends of the Eneloops..flat head aluminum bolts inserted into a section of model airplane fuel line holding the contacts in place, circumference held with a section of bicycle inner tube... the 3 cell battery pack worked best, and would fit inside a MagLight tube.. since fabricating the ceiling fan motor, have had only one outage (Irma) and I usually get a bulk pack of D cells expressly for the fan motor on hand, so have not had to use the adapters...