Maybe this is an option ? i found it in an old thread here :
http://photo.net/medium-format-photography-forum/00440MBob Salomon , Nov 20, 2002; 02:55 p.m.
If you have the NiCd battery for the 60 series get the Gel Cell battery.
Or simply get rid of the memory effect by discharging the pack, under the proper load, and recharging it 3 or 4 times.
Frank Kimble , Nov 20, 2002; 07:50 p.m.
Get the "dryfit" battery, its a gel cell type battery. No memory, can be topped off jut before you need it. When you switch, there's a "tab" that must be switched inside the battery housing, takes couple seconds.
Jay . , Nov 21, 2002; 04:41 a.m.
Only get the dryfit if you use the flash regularly. That battery is "use it or lose it". One of the reasons I never bought a Metz 60-series, much as I liked it, was that there was no disposable-battery option for occasional use.
Scott Walton , Nov 21, 2002; 08:45 a.m.
Sorry to say but this is why I went with the 45 series and not the 60 when I started with Metz. Not to many choices with the 60.
Jack Chase , Nov 22, 2002; 01:28 p.m.
Short-term, follow Mr. Solomon's advice. Long-term, get the dry-fit. I have both a 60 and a 45. I use the 45 when I don't need the power of the 60, & when I don't want the inconvenience of the external pack, as well as taking it along as a back-up for the 60. (Though the 60 is so reliable, I've never needed to use the 45 in the back-up role.) The 60 with dry-fit is good for lots and lots of full-power flashes, and like the other poster said, you can top it off just before using it without worrying about memory effect. With the nicads in the 45, I have to remember to drain them all the way when I am done, then recharge them just before use to avoid having to deal with the memory effect.