Olympus has also thought that you can accommodate the battery compartment, which must be unclipped for mounting in the battery grip. So you can at any time remove the handle again (if you want to transport its 620 times in a small bag, for example). Whether the duration of the second battery needs now, I can not say. Battery problems I had never. And here is in my eyes the only drawback: you never know the charge status of its battery and loads best ever both on.