I replaced the batteries on my Sola 1200 light years ago. You need to source the same spec battery cell, and then there was some soldering required. It worked fine for a couple of years until I dropped the light and cracked the case open.
Thanks, from the website linked above, it looks like 2 x 18650 batteries at 3.6V each. I was hoping to go with the highest mAh batteries I can get my hands on. What do you think?
