How does the battery case work, i.e. does it slide open or does it have cover to twist off with a coin?
2029862
There is a small tab above the battery door. If you press down on it with a fingernail, the door lifts off.
592451
Are you talking about where to put the batteries? If so, you don't open the back. Open the faceplate and inside you will see a white cover. It has 2 big screw looking things that are latches. Turn them with a coin or wide screw driver. When they are horizontal, lift the plate from the flange between the 2 latches.
1748463
It opens from the top. There is a small square piece that fits on the top. It's easy to lift off and the battery is on the underside of this piece.
315540
At the opposite end from the silver on/off switch there is a tab sticking out...press down on the tab and the battery cover will open.
352770
You have to grab the end and pull while pressing down on the little yellow lock tab in the pocket clip. You can also use pliers to squeeze it while sliding the cover back. It is not easy that's for sure. Two triple A batteries are required.
271555
To open, turn the switch off and gently slide the battery cover forward to take it off.
456765
There is a small battery door at the bottom of the back side. It slides down, I believe. I have had mine for a year and has worked well.
2063487
Like Jot said, there is a small compartment that holds the two AA batteries. I sometimes have trouble getting it to slide out. Try applying some downward pressure while pulling on it. Another thing would be the pin. There is a lockout pin that came with the detector that is designed to keep the battery compartment from being opened. If it is in it, you would need to remove it before the compartment is opened. I don't use the pins myself because I change the batteries twice a year.
322188
The battery compartment slides out from the side of the BLACK box. Look close, you'll see a tiny raised 'handle'; it slides out like a drawer.
2014634
Once the top is off, hold the bottom and top at the same time and pull in different directions. The bottom will slip off to reveal the battery case. It takes 1 triple A battery.
1834930
Try a coin. It is kind of hard at first, but if you push up on it, it snaps out. There looks like two openings for the battery, but it's the upper one. The lower is for the little circular stand that comes with it.
379115
It's a little tricky :) Turn it over and you have the black back cover with the big "B" on it. If you look at the edges you will see two small triangles along the sides. If you push down on the back and spin the whole back cover in the direction of the arrows (not even a quarter of a turn), the back will simply pop off and you'll see the battery compartment. Hope this helps...or write back if you can't get it. --CC
1525368
The battery compartment on mine is actually quite easy to open. I can just slip my nails in the crack at the top back and push slightly and it slips right off. You could also use the tip of a butter knife or something similar to slip in the crack and nudge it open, then it will simply slide off. To get it back on, make sure you line up the top up level and slide it right up through the little plastic "holders" that are on both sides.
665205
The cover does not have a clasp, so it will flip open if you're not holding it closed. It's more like a folder.
659057
There's a slide-out battery cover right behind the wrist band on the back. It's a little concealed by the band but you can still get to it.
1678029
Use a coin to turn the slot on the side of the player until it unlocks. Then you slide the cover off, replace the batteries (4 AA), slide the cover on and turn the slot back to the lock position with the coin. We use rechargeable batteries because it uses up a lot of power.
2014631
The metal base slides off. Just pull the plastic mechanism from the metal sleeve. Then the battery is exposed.