As a long time Metz 60 user I've grappled with battery issues for years but I've never tried the Lithium batts which might be the best option. https://www.flickr.com/groups/421691...7612486080070/ discusses the Lithium batts and they seem to recycle faster than the Sonnensheins.
The last 2 new Sonnensheins that I bought from an Australian distributer performed WORSE than my old batteries with only about (approx.) 3/4 of the capacity. Maybe they where stored too long before I got them, I don't know, but I will never buy Sonnensheins again.
For MANY years I've used external 6 volt 12AH gel batts attached with fly leads on 2 of the 5 Metz 60's that I regularly use. These have much greater capacity and are extremely cheap to replace but are quite heavy (although this doesn't matter much in my line of work, and some times the weight is an advantage). The fly leads that I use are shielded well to avoid shorts and are heavy duty. Over approx. 5 years of use they have never been a problem, have never developed a poor contact, shorted or come loose.
One disadvantage that I've noticed with some batteries is that their internal resistance might be slightly higher so the recycle times can be a little slower, enough to matter anyway. My external batts take approx. 2 secs longer to recycle at full power. The Sonnensheins seem to recycle faster, but they are still not worth the money IMHO. If I ever have to replace them I will go all Lithium.
Last edited by jjphoto; 03-01-2014 at 04:18 PM. Click to view previous post history.