Does anyone belive the Fitorch can take a 18500 battery? It can definitely use a 18350. It seems to have a large spring. Measuring it looks tto be 15 extra mm deep but I’m not sure. How much is a good button top 18500 and where to buy them for a trial?

Anyone know a simple 18500 flashlight I could get in case the battery won’t work in the Fitorch ER16?