The Metz 50-40 NiCad Battery is originally supplied with the 50MZ and 70MZ series flashes, and does not come with a charger. It requires the 759 charger.
Depending upon many factors, the recycling time varies from 0.1-5.0 seconds and the maximum number of flashes varies from 50-2000.
Reviews Metz 50-40 NiCad Battery for the 50MZ & 70MZ Series Flashes