Recently I moved on from the world of DSLR to the Mirrorless 4/3 OM-D EM-1. This machine takes a BLN-1 battery and hovering between $80 and $120 depending on where you buy them and how desperate you are they are the one disappointment with this camera. That said, the same disappointment is shared among all the brands because they all price their batteries higher than they should.
Since any mirrorless camera has to display the image so you can compose they chew up a lot of power and go through batteries considerably quicker than a DSLR. This means that for a four or five hour street shooting session I need a couple of batteries and for long exposure work even more because I'm making the camera work much harder. This is cool and is expected.
I started the hunt for a non genuine battery and a good friend +Ananda Sim recommended betterbatt and so did a few other people. They're available from http://www.betterbatt.com.au/ and they don't even know I'm writing this review although I'll probably tell them.
The first thing I check when I'm buying non genuine (I've used Wasabi in my past camera life) is the ratings on the container to make sure they match or exceed the genuine battery.
VoltageIn this case the battery is marked 7.6v which matches the Oly BLN-1 - it's critical that this number is exactly the same as the genuine battery. Less will make the voltage converter in your camera work hard and will lead to early battery consumption and early failure of the battery. More will either make your camera hot as it deals with the excess voltage or kill it.
It should be noted that this voltage figure is the nominal voltage. When a battery is fully charged it will usually perform over this stated voltage by a small percentage gradually dropping back as the battery loses power.
Lithium batteries have a good steady curve over the power usage but have a sharp drop off once they reach the critical point. Your camera will recognise this and shutdown to avoid corrupting cards or damaging the machine. Generic batteries are likely to have a different profile than originals but the camera will have enough engineering tolerance to still work properly. In this case the Oly detects the fall fine and stops you from over discharging the battery.
Ability to supply power
This battery is 1020mAh / 7.8Wh. These numbers show the batteries ability to store and supply power. The battery will store 1020mAh (milliamp hours). These numbers can be bigger than the genuine battery and your battery will give you better life in the camera. If the storage rating is smaller you'll get less life per charge. Being different can't damage your camera and often the non genuine batteries store more or less power. Genuine battery manufactures may use cells designed specifically for their space which gives them the most grunt possible per cubic mm. Generic manufacturers usually use standard cells and fit as many as they can and filling the voids. This means that often generic batteries will not last as long as originals.
Betterbatt warn you on their website (and again in person if you pick them up from the store) that you cannot use the Olympus genuine charger because it "talks" to the battery and won't charge it.
I've found in my experimentation that at least this generation of the charger charges the battery fine. I also have the Betterbatt charger on the left and it charges the batteries in about 1.2 hours where as the Oly takes nearly 3 hours.
There is no noticeable run time difference between the battery charged in the Oly charger and that charged in the Betterbatt charger.
When you're buying non genuine you don't void your warranty, but shop around, check the reviews, buy a reputable non genuine brand because Lithium Ion batteries are lethal if they're made incorrectly or have low production quality. Seriously, these batteries have caused plane crashes through fire. Once a Li battery gets to the heat where it will burn it will light up and it will not go out. It burns so hot that it will destroy whatever its in and probably a good part of what is around it.
These guys are in Melbourne and source and test batteries from various suppliers rebranding them with their brand. They have a warehouse which has a pick up location in Flemington but you need to order before you go and wait for the confirmation before heading there. They also mail them out. I went to pick them up because I needed them quickly and because I wanted to see their operation. They are basically a small company run by a bunch of younger people which is awesome to see.
These batteries are serving me well and the pre-configured battery trip voltages in the camera for the warning display and the battery out indicator work fine for both the genuine battery and these ones. I'm happy with my purchase at roughly 1/4 of the price for a genuine battery.