[Olympus BLN-1] It's best practice to have a spare or a few spare batteries when out and about taking photos. Buying original doesn't hurt either since it doesn't break the bank. Work as advertised.

[Olympus BLN-1] Camera batteries are essential to the use of the camera. The choice to buy a battery that is not sold by the camera manufacturer, though it might save 50% or more in cost, comes with a compromise that I am no longer willing to make. Too many times I have taken an off brand battery from my bag, and even though it was topped off on the charger the day before, had it drop dead on me after a few shots. Batteries do not live forever, I know. But the batteries sold by the camera manufacturer, do seem to live longer and perform more reliably. I am wiling to pay twice the price for the reliability. (But I do wish it weren't necessary. :-)

[0.15 lb] Much improved compared to the battery for the previous EM1 - longer lasting and takes only 2 hours to charge. Also comes with nice plastic case.

[0.15 lb] How does one review a Battery! Well one might want to consider reliability, peace of mind. I do not want to be on a shoot and find I have a battery failure. One can go cheaper but ask your self is giving up longevity and dependably worth it. I am a serious photographer. I shoot an OMD 1 with a battery grip.

[Lithium-Ion] I have 2 Oly bodies, a P5 and an M5x2, and previously an M5, with 8 batts for camping trips away from chargers. My Oly BLN-1s have carried a good charge. I mark my batts as to when I put them into service. Only now the 2 I purchased with the P5, in 2012, have swollen enough I won't put them into the camera. I have no experience with an off-brand competing with Oly, but very satisfied with my experience with Oly batts and chargers.

[Olympus BLN-1] Yes, it costs more then third party but I appreciate the reliability of brand name batteries.

[1220 mAh] For the past three years Ive used an Olympus and a trio of brand X batteries for my EM5 II.  During this last year it has become clear that the off brand batteries are weakening, and they were never quite as good as the Olympus.  Therefore, I decided to get another Olympus battery to increase reliability and longevity.  There is certainly a difference in price, but Im tired of those others conking out so fast.  My original Olympus seems to be as strong as ever.

[1220 mAh] It is the backup battery for my Pen-F, no problem at all. Trusting a second battery in your bag is a comfy feeling.

[Lithium-Ion] You will need it. Buy the battery and you'll be surprised that you'll never want to go without it again.

[0.15 lb] These are more expensive than after-market batteries. I can't say for sure if they are better. But given the cost of a battery vs. the cost of a $1,000 camera, I'd rather not find out.