No
sigelei 20W owners have stepped up to answer this so I'll give it a shot. Because the 20W uses a 18xxx series battery I'm guessing that Sigelei uses the same battery spring in the 20W as they do for the V3 and V5 that I am familiar with.
Overheating at the battery spring is a serious issue that should be resolved immediately. The first area to look at is poor B- contact between the battery and spring and the spring and battery cap. Next, look at contact between the battery cap and the battery tube.
The new and relaxed springs are about 17mm tall and will gradually compress over time. If the spring has compressed too far contact between the spring and battery may be compromised. Carefully stretch the spring back to its original height being careful not to distort the shape of the spring. The narrow top coil of the spring should fit flat on the center of the battery B- end. The wide bottom coil of the spring should fit tightly into the battery cap. If the bottom coil does not have a snug fit into the battery cap then widen the bottom coil until it does. Clean the spring with rubbing alcohol and a clean rag. Clean the inside of the battery cap the same way.
Oh yes, it doesn't hurt to buff terminals on the battery itself with a soft, clean cloth.
B- continuity can be compromised by dirty threads on the battery cap and the mating tube section. Clean these tube threads thoroughly with alcohol and a rag.
If the steps above do not cure the problem then put a little Noalox on the battery cap and tube threads. Some have even put Noalox on the bottom coil of the battery spring. Noalox on tube threads has been known to solve or prevent a lot of B- path issues on tube mods.
