These batteries are not comparable to other, much better off in performance. They hold a charge very long, are reliable and so I run so that a flash and can be felt for a long time working with high performance, until the batteries are empty. We have served us for a special battery charger, in which you can adjust a lot, maybe it's part of it. Unfortunately, one can so well when writing such reviews than ever to address the long-term experience. The service life is supposed to be very high, which would justify the high price in addition.