How do I change the battery in my welding hood cause sometimes the lens will darkin and sometimes it won't? Also the lens will not adjust the darkness when I change the shade

I open my Optrel OSE Satellite K601 hood and found they use glue on the outside edges and then a rubber compound over the electronics. Rubber compound also holds the case tight. You can gently cut a square out of the plastic case about 1-1/2" square around the information printed on the back side of the case. Under neath you will find (2) panasonic 3V button cells. Each have 2 tabs that are soldered to the board. The battery's have a plastic sleeve shielding them from the rubber compound, so they will pop out easy after removing solder and lifting tabs. Be careful heating tabs as there are some small SMD resistors and caps very close to tabs. Once removed you can by the batteries with tabs at many battery suppl stores on line and solder back in. Or do what i did and buy a double battery holder with battery clip retainers, then mount in helmet and wire it to the board. Then use epoxy to install cut out piece of plastic on case. I actually used the new plastic adhesive that uses UV light to cure (Stuff is awesome). DO NOT ATTEMPT TO OPEN CASE!!!!! You will regret it as it took me all day to repair the damage i caused to open it. Just cut around the data on the back of the case and the battery's are under neath. Each are about the size of a quarter. Also to remove the side control panel, pull the large knob off the panel, then un-clip the back cover inside the hood, then pull out on the panel then turn it to its side and then slip it through the hole in the hood.

The Optrel OSE Evolution does not have a replaceable battery. Nice helmet when it is working; very comfortable but too stink'in expensive to be just a grinding shield. The AD Cartridge is completely sealed so replacing the batteries is very difficult, with a low likelihood for success.
There is a good chance that the batteries are OK, just discharged. Placing the helmet in the sun may help, but unless the sensor ports are covered, charging benefit is diminished by power consumed to darken the lens. To increase effectiveness of solar charging, cover the sensor ports with a suitable tape to completely block light from passing through. Expose the helmet to direct sunlight for charging. Note that the lens should not darken if the sensor ports are properly covered. As an alternative, you can use a CFL bulb (at least 100W equiv.) in a reflective fixture to create a charging light source. Place the helmet within 6 inches of the light such that the charging panels are able to absorb as much of the light energy as possible. A few days of exposure should fully charge the batteries. As long as the helmet and AD Cartridge are not getting too hot, you can leave it like this for as long as you like.
If this does not restore functionality of your helmet, you can purchase a new Optrel Auto-Darkening Cartridge. These are really expensive however, so I chose rather to by a new helmet which I like about as well. Miller, Lincoln and Speedglass are all good choices. Good luck.

This Helmet is solar powered leave it on your dash to charge it a few hours will work just fine there is no battery the solar cell holds the power Try getting a full charge on it then see if the darkness will adjust .