HC1 plus NP-QM91D
 

I have read reports that this battery is so deep, one has to angle up the viewfinder in order to view through it properly.

Some people recommend getting 2 NP-QM71Ds instead. Does anyone have experience with this issue?

I use an FM-70 battery on a small, 5-year old Sony model. It is an ideal size for both good capacity and not being too big. The FM90 they sold for it was way too large for comfort and since I get about 3.5 hours recording time from the FM70, it is a much more practical size. With the great energy-efficiency these newer models have, one medium-sized QM71D is all I'd need besides the furnished battery. Two QM71Ds would keep you shooting all day. No sense in making it awkward to use, for power you won't likely need.

I have both the NP-QM71D and NP-QM91D batteries for my A1U. While I can use the viewfinder with the QM71D without having to angle up, the battery does press against my right cheek (under my eye). After a short while, that gets pretty annoying so I end up moving the viewfinder up anyway. The angle isn't as steep as it would be using the QM91D however. For the most part I usually monitor using the flip out LCD so it's not so much of an issue for me.

Get two QM71Ds. That way you can keep one charging while the other is in use. With the big one, once it's discharged, you then have to wait for it charge before shooting again.

The idea with two batteries where one is charging while the other one is being used is a good one, but only if you have an external charger.

The HC1 is used for charging the battery, so you have to invest in an extra charger if you go for two Qm71s.

I use the LCD screen most of the time and I have an QM91, so the bigger size of the battery is not an issue for me. Especially not since the big battery gives me a better ballance of the camera with my Canon Wideangle adaptor.

It depends on how you use your camera. I have 4 batteries including the NP-Qm91D. While it is true that the size of this battery means you have to move the viewfinder up, when I have the camera on a tripod it makes no difference. I set up the camera on the tripod and take into account this extra size in advance as well as all the other things I have to consider (zoom control cable placement, matt box and filter settings, microphone placement ) so the extra size is no big deal. In fact I like having all that extra charge so I can elimate the need to change batteries during a shoot. The only time the 91D might be a problem is when I hand hold
DKane

Sima SPM-13 Charger
 

I have used the Sima SPM-13 charger for all my Sony lithium batteries for the last 5 years. It has adaptors to fit most models. If the QM-71/QM91 are differently shaped around their fittings, I'm not sure about them. The people on the phone line or on E-Mail at Sima are very knowledgeable and honest about compatibility with their products and will tell you what matches or not. It works with my NP-FM50/FM70 and NP-F570/F960. I've used it steadily for 5 years and it charges moderately fast and is dependable. It charges about 50% faster than the built-in camcorder chargers. It lets out a loud shriek when it makes a good connection at the start and 3 more when it's finished. It cost me about $40. and has been a real bargain.

Looking at their website today, I see a new universal charger model, the UDC-3X. It works with lithium, Ni-Cad and NiMH batteries of all common voltages and brands. It's listed at $70. The SPM-13 is no longer shown. The UDC-3X would be very good for anyone with older camcorders as well as new ones and has all three battery types to charge. I may buy one of them myself.

I see a lot of people who, like myself, invested in two or three of the larger lithium batteries for camcorders. This isn't necessary, in many cases. With my VX2100, I use my medium-small NP-F570 almost all the time, as it gives me about 2 hours recording time. I carry my bigger F960 along, but have used it only a couple of times. It's good to have one large battery on reserve, but unless you're shooting more than 4 hours of footage a day, one medium-sized and one larger Sony battery will be enough. If you're going on a field trip away from a power source, then you need a bunch of extra batteries.

http://www.simacorp.com

thanks for all your comments. Yes it does depend on how one uses the camera. I like to use a tripod as often as I can, so it wouldn't be an issue in that mode. But I hand hold quite a lot as well.

The thing is I find that shooting with the viewfinder angled up feels weird. I suppose it's something one could get used to, but it's like suddenly assuming an angle of view of someone a few inches shorter and it's amazing what a difference that makes to close range shots.

How Long does a QM-71 Last on the A1U?
 

Approx. How many hours of shooting time does the QM-71 battery last with the A1U?

Using the viewfinder?
With the LCD screen open?

Battery Times
 

Dude, you rock. Looks like I"ll need at least another QM-71.

I just bought four QM91D batterys from this guy on ebay. I don't really know when I'm gonna have the chance to charge them so that's why I went with them vs the 71D.

I'll let you guys know if they are really genuine sonys.

Do all Sony M-series batteries work with the A1/HC1, please? For example FM70, FM90, FM91.

The Sony page says that the NP-FM50 is the one that is supplied with the camcorder. I'd assume that the FM70/FM90 would also work, but someone who has these camcorders should be the one to give a definite answer. I use both an FM50 and FM70 on a 5-year old Sony camcorder and also with a DV Video Walkman VCR. The supplied FM50 never had much capacity and went downhill fast, but the extra FM70 I bought, held up very well. It seems that all the small batteries that Sony provides with camcorders are as poor in durability as their larger, extra batteries are good.