The method discussed in Tesla forums indeed seems to be effective. Particularly, it’s noted to work on older V2 Supercharger stations that lack actively cooled cables. Wrapping the charging connector with a wet towel or cloth not only provides protection from the sun but also allows for higher current transmission due to the cooling effect from evaporation.

One Tesla owner managed to increase the charging speed from 60 kW to 95 kW on a hot day at a V2 Supercharger station using this method. The Out of Spec Studios team achieved even better results. After plugging in their vehicle at 2% charge level, they increased the charging speed from 58 kW to 119 kW by wetting the station’s cable, hitting a bottleneck at 34% charge.

However, in the case of the newer V3 Superchargers, except for the Cybertruck, the method is reported to be less effective. The Cybertruck, with its 800 Volt architecture, divides the battery pack into two 400 Volt subunits to increase the current beyond 700 Amps. Although the station has active cooling, this high current can still cause heating in the cables. Therefore, the wet towel method is said to work for the Cybertruck at V3 stations.

It’s important to note that this method doesn’t work miracles; it only provides a few minutes of gain. Ultimately, the temperature of the battery cells remains the most critical factor affecting charging speed.

Regarding safety, there are no reported drawbacks to the method. Since charging ports are waterproof, it’s possible to charge even in the rain. However, since this method isn’t recognized by Tesla, the responsibility lies with the user.