i have one brown lg battery and one that is also brown saying IMR 18650(which is apprently a lg battery i read as ell,the first battery im pretty sure it was a lg52 battery(the lettering is off now)if i have two types of lg batterys is it unsafe
this^I wouldn't run them together in a dual battery Mod. I would recommend getting two identical batteries at the same time and "marry" them for use.
If ever in doubt do not use ,is it dangerous not even sure if the one without print is areal lg