It doesn't appear to work at all with the battery removed.
So ..... five stars.
But seriously folks ...... the battery's ability to hold a charge and perform under stressful conditions, e.g., cold, will be tested after a year or two rather than a few months.
For a general review: I've tried a third-party battery (CTA) that was well-recommended and priced half of Pentax. Eighteen months later, it was holding only half the charge of my Pentax battery and I was scrambling to get at my spare. Lesson learned.
i am using Pentax D-Li90 Lithium Ion replacement battery as a spare battery. i was charging the primary and back up batteries at the same time, about 8 hours to charge, but because they last longer than expected i now only have to charge 1 battery at a time. unless i expect to spend the whole day shooting then i would charge both just to be safe. on average i seem to be getting around 1000+ pics per charge. i do not use live view however unless the occational review of a pic. they seem to be doing ok for me!
Not really much to say. Same battery as used in the K-7, (I purchased this for a K-5). When I purchased the K-7, additional OEM batteries were quite expensive. I went with 3rd-party batteries. The price seems to really have dropped to the point where purchasing a non-Pentax battery is no longer cost effective. Go OEM Pentax. Really can't go wrong, especially at these prices.
I bought this battery when I bought my Pentax K-7. I keep both the original battery and this battery in my camera bag. I take tons of shots when I'm out with my camera (normally at a zoo, car show, etc.). Since the K-7 uses battery packs instead of disposable batteries, if the batteries run down, my photography day is over. So far I've shot all day with one battery on a full charge without any problems. This battery just keeps going! I don't worry about whether I'm using the flash or not, as this battery has enough power that it's never been an issue.
It's good enough that I've not bothered buying the external battery pack for my camera.
I have tried to get a Pentax battery before and either they were sold out or they were $75.00! I couldn't even buy one on the Pentax web site--this was last year, so I don't know if they have them now or not. Anyway, I snapped this one up ASAP! It came to me very quickly. It was in the official Pentax box and the battery is exactly like the original one in my K5II. It charged right up and I am using it with no problem. So happy to get it.
It's a spare battery, just like the one that came with the K7. It holds a charge for a long time allowing me to shoot without worries of a depleted battery. Not sure I can add more to the reviews just glad I picked this up @ a great price here on Amazon and encourage the purchase of a spare battery if you haven't done so already.