June 04, 2015
If you're coming from the DSLR world, one of things you'll quickly realize is that the power drain on the M43 cameras is going to be higher simply because you're probably going to be using the display a lot more and well the battery capacity sizes can't be as large simply due to the physics of the size.
With all that being said, you really want to have at least 3 (1 that comes with the camera + 2 more) batteries in your arsenal. On trips where I'm outside all day, I can easily blow through 2 batteries if I'm shooting a lot. Having that third is critical. You don't think you'll need until you realize you do. Just do it and buy two more of these. You won't regret it.
March 27, 2014
I have in the past purchased after market batteries for my Olympus cameras with varying degrees of quality. Even the best ones don't seem to retain the charge as long as the Olympus originals, nor do they last as many recharging cycles without some drop off in the charge.
You have to ask yourself the question on whether you want to pay less up front and know that you have to keep changing batteries when you are out or pay a bit more & get the longevity. For me I have changed to paying more up front and having it last. It is well worth the cost.
May 28, 2013
Took home 2 of these when I got my new OM-D E-M5 last year.
I am always charged and ready to go with one charged battery installed and one in my bag. I am thinking now may be a good time
to cover myself with backups since vacation time is coming soon although they appear to be still going strong.