Options - some flash pack mods required
When I went looking for a dryfit, it was to rehab a 60CT-1 that I bought at a garage sale for $20. Only the photo stores sell the Sonn.. batteries with the litle flat round terminals - $70 or so in my local suppliers.
But the electronics stores, which sell sealed lead acid batteries, so that people can keep their UPS's ticking, also sell products by Sonn... with push on tab terminals. I bought one of the correct size for $35, bent the termianls backwards so that they are now in the same spots as the photo type battery.
I chiseled the plastic spacer out of the bottom of the battery pack to take the slightly taller (due to bent back terminals not contact pads) substitute battery, and glued the plastic orientation lug wrenched from the old pooped out battery ont the new one. If I get back to using an OEM type battery in the future I can tape a piece of foam core in where the removed spacers are, and the OEM battery will have the correct height to mate with the battery spring contacts.
I took the pooped battery, and sawed it apart to reuse its case. When I am shooting in my studio, the Metz is actually my soft box main light. I install the old battery case into the flash in lieu of the newer battery in this configuration. It is hooked to a surplus PC power supply housed in an old cookie tin. The power supply feeds the flash unit 5V at up to 20A, so the flash recycles quickly, and at the same rate all day long.
