This is a two-battery version of our generic Milwaukee M12 battery adapter shield¹, with some significant differences in the ordering options. Read these carefully and check out the embedded links before ordering - Tindie's options system can be confusing and some choices may be unexpectedly more costly.

The first option is straightforward: two adapters on a single spine. This uses the original single-battery design¹ for close-packing an array by placing them in alternating, opposing orientations. The short-throw, front-loading design further serves this purpose, enabling a closely spaced array in both X and Y directions. Separate leads for each bay. No plug(s). No electronics (no hot-swapping).

The last three options incorporate our Dual-battery Switcher¹, which enables battery hot-swapping: either battery can be replaced with a fresh one, while the other continues powering connected devices. Both are used simultaneously when connected.² The second option has no plug on the outgoing power line.

The third and fourth options add a USB-C power-only plug¹. You may choose between Up-Down and Left-Right orientations.

All options have a second choice drop-down for 6" or 12" leads.

All wiring is 2P 28 AWG color-coded, PVC-jacketed, tin-plated, stranded copper wire. The wires are paired for routing convenience, so you'll have to split them apart if they will be routed separately. Designed for at least 3A at 12V.³

Mounting holes are sized for common #6 wood screws.

¹ We strongly encourage you to examine the text and photos at other listings in order to fully understand this listing - they have many important details of subcomponents which are omitted here.

² DO NOT parallel rechargeable batteries without a device like this attached, or they will back-charge each other, significantly reducing lifespan and possibly igniting a lithium fire. This is especially dangerous if the batteries are at different charge levels - which is effectively a short-circuit of one battery through the other.

³ With no intentional allowance for over-powering, check an ampacity chart for resistance if you extend the wires or load it more than specified above. This product is NOT comparable to the high-amperage generic "PowerWheels" adapters available on Amazon/AliExpress. WE ACCEPT NO LIABILITY FOR CONSEQUENCES RESULTING FROM USE OF THIS PRODUCT AT POWER LEVELS EXCEEDING THE LIMITS NOTED ABOVE OR MODIFICATION OF THE WIRING.