Batteries can typically not good. They tend to self-discharge and after months of inactivity, they are empty. By contrast Eneloops help. The black Panasonic Eneloops have optimized a very high capacity (2.4 Ah) and are on fast output - which reduces the recharge time between two flashes. However, the costs and lifetime: While others are Eneloops hold up to 2000 charge cycles, high capacity and fast output is bought with an average life of 500 charging cycles.
I have four compact flashes and eight by four batteries (half of whom are black Panasonic). Since I photograph a lot and excited, I berbrauche in each flash about two battery charges per month - a charge cycle per month .... 500 months ... from the head: about 42 years. 500 charging cycles are enough for me!
