I have an old Nikon D2H camera which uses EN-EL4 battery, however, an original Nikon battery costs RM400+, which is ridiculous since they are just standard 18650 cells inside, which you can see from the pics below. Below is part of the process of removing the old 18650 cells, there's 3 of them. I need to desolder and remove the tabs. I read some guides that the original cells are high current 18650 cells, needed by the camera. So I bought some LG HG2 cells rated at 3000mah capacity, and has 15A discharge rate, which is ideal for this application. This should be even better than the original EL-EN4A of 2500mah capacity. But I will have to test and see. This is how the old 1900mah cells look like now.