The factory spring is not a hot spring. This is for certain. It is the cheapest battery spring I've ever seen in a mod. There is excessive heat and short protection built into the Vamo board. The unit shuts off if either occurs. The spring I replaced it with is much thicker than the factory one which is better. A hot spring is fine if you can find one that fits but if you want to really be cautious you should just buy a vape Safe chip. I intend to. My battery and tube haven't even gotten warm since I changed out the spring. No worries at all.
Also, the cheap spring it came with readily compresses without returning to its original height. I have used flatop IMR and protected high-drain batteries (slightly longer than the IMR). Before I had no problem with the IMR, but now after using the other batteries the spring often loses contact for a split second and the Vamo shuts off. I have tried stretching the spring but after compressing it stays compressed. I would have to agree they used the cheapest, crappiest spring they could find. I will replace mine with a hot spring when I get the chance. The bottom of my Vamo has almost no black chrome color left also. It is the worst coating job I have ever seen on a mod. Anyone else experiencing this yet?