Summary: Since the basic battery included in my Sony Handycam has gone too fast, I purchased this one. this one lasts longer. But the size and shape of the battery is big and thus block my hands to operate my handycam.

Summary: This battery can go on all-day outings and I keep my camcorder turned on without worrying about running out of power. I can also use my camcorder on battery power for several days without having to recharge the battery. The battery level indicator on the back lets me see how much battery life I have left without having to use any in the process.

Some small downsides are to be expected. It takes a long time to go from fully drained to fully charged when charging from the camcorder. You need to remember to start it charging the night before the day you need it.

Fortunately, the NP-QM91D can be recharged before it's fully drained with no resulting loss in capacity. Because it can be recharged at any time, you never have to let it fully drain and never have the long wait for it to fully charge after you've done it the first time.

The NP-QM91D's increased weight shifts the center of gravity significantly and takes a little time to get used to. The size means that this battery protrudes beyond the back of the camcorder. Although the viewfinder can be extended to accommodate this, it makes much harder to connect the AC power adapter. Additionally, the battery isn't held in place as securely, and has a tendency to come off more easily.

Overall, these are small trade-offs that I can adjust to in order to have a camcorder I can use all day without needing to recharge.

Summary: This is a really good choice if you do the recording for something continuously for more than two hours. It may last to more 190 minutes of operation depends on the recording mode you choose. And the one tough capacity indicator really easy for you to check how long the battery is gonna last.One other good thing is you don't have to wait after the full drain to do the recharge.The drawback I see is that this battery is relatively big to put on my HDR-UX1 and make it more heavier then difficult to handle.