So my Vamo was heating up a bit last night at the bottom. No too much but it was noticeable. I took out the battery (new AW-IMR 18650 near full charge) and looked at the spring. There must have been a short because the inside of the cap looked a little burnt where the coil sits around the "nub". Disconcerting to say the least. Neither the battery nor the positive connector, showed signs of damage. I figured that the bottom spring was the culprit. It's really flimsy. Too weak imo for a boosted circuit. I went out today thinking it would be easy to find a battery spring but let me tell you. It ain't. I went to 3 hardware stores including Home Depot and Radio Shack and none had what I needed. I ended up at Fry's Electronics looking in the flashlight parts section. Still nothing! On a whim the cheapest flashlight they had was this. I couldn't open it in the store so I was going blind. It was a $6 gamble so I figured wth. WHen I got home and opened it up, EUREKA! The spring inside is the same size and noticeably sturdier than the Vamo's. I just had to snip a bit off the bottom of the coil and widen the connecting end. I cleaned the cap with 90% rubbing alcohol and snapped on the new spring. It fits more snugly and has better contact with the body. The 18650 has absolutely NO RATTLE anymore as well. Since using it, the Vamo has been totally cool to the touch even when chain firing. If you don't want to pay and wait for shipping, and need a spring replacement that fits our mod,
this product has one. Toys-R-Us has the same one as well. If you don't like Spider Man, you can get Spongebob, Dora, Hello Kitty, and Batman.