Mechanical Dragon Fury-S Mod, Mountain Little Boy RDA, 40A Aspire Battery: Overheating & Sparks

Hello, sorry as there is a bad department.
I own a fashion mechanical dragon fury-s with a mountain little boy rda.
40A aspire battery.
Heater about 0.3ohm.

The problem is that from the very beginning of use, the button at the bottom warmed up, now it is unbearable.
The battery itself is cold, but I noticed little sparkles when pressing.
Because of this, it sometimes kicks with electricity and heats up, the battery is kept very short, which is obvious in this case.
Anyone had a similar problem? Some solution ?

1. What battery voltage?
2. The fact that the button heats up and the sparks jump (electric arc) is no wonder - a very high current flows through it. To eliminate this, I did a layout to my colleague, such that the button turned on the MOSFET transistor, which in turn conducted the entire current, so the button contacts are not loaded, they do not heat up, and the mod has a bit more power, because the heat that was released on the button is now released on the heater.

michal_r1998 wrote:

1. What battery voltage?
2. The fact that the button heats up and the sparks jump (electric arc) is no wonder - a very high current flows through it. To eliminate this, I did a layout to my colleague, such that the button turned on the MOSFET transistor, which in turn conducted the entire current, so the button contacts are not loaded, they do not heat up, and the mod has a bit more power, because the heat that was released on the button is now released on the heater.

1. Aku has 3.7

2. I know it's losing power, the point is it's a tube.

Well, not much can be done