Walter Battery Adapters (Surface Technologies)

They are the same class of battery, measured at two different moments. Five lithium cells in series read about 20V fresh off the charger with nothing drawing from them, and settle to about 18V once a tool is running. A brand that prints 20V is quoting the first figure and one that prints 18V is quoting the second. That is why an adapter between an "18V" platform and a "20V" platform works: there is no conversion to do.

Use the selector at the top: pick the platform on the other side of the pair and it takes you straight to the one adapter that joins them. Every combination in that list is one we actually make, so if it is there, it exists.

Yes. Use the swap button next to the selector above and the page turns the search around, from Walter Technology 18V tools back to the batteries that can run them.

No. The adapter carries current from the battery to the tool and does nothing else — there is no charging circuit inside it. Keep charging Walter Technology 18V batteries on their usual Walter Technology charger.

Used with undamaged, compatible equipment it is not expected to. Walter Technology 18V batteries are lithium-ion with their own protection circuit built into the battery, and it keeps doing its job through the adapter. Stop when the tool noticeably slows rather than running the battery flat, and stop using the adapter if it becomes unusually hot or the contacts look damaged.

Usually. What matters is the socket, not the badge: if the battery slides onto a Walter Technology 18V tool and locks the way an original does, the adapter will take it. Aftermarket batteries do vary in moulding, so if yours looks unusual send us a photo and we will check before you order.