In an effort to counteract overheating, I have added cool air intakes connected via 4″ diameter ducts to the fans on my TSM2500 (CH4100) chargers.

I used a 4″ flush to the floor “snap-in” PVC floor drain (designed to be cemented inside of a 4″ PVC pipe) spray painted flat black as my intake, connected to a 4″ aluminum flex dryer hose (mostly ran straight through, but the flex hose allowed me to vary the length) with worm screw clamps (a.k.a. hose clamps). The single most expensive part of the install was the 4″ hole saw ($15 on ebay, or $20 at the store). I could have saved $5 by going with a less expensive vinyl dryer hose, but I like the rigidity and appearance of the aluminum.

I used some black electrical tape to dress up the ends, and black zip ties to hold the hose directly over the fan shroud on the chargers.

Outside of the truck, you really have to look to find the air vents (after I spray painted them black…)

The only “exotic” tool required was a right angle drill, which made it possible to create the holes without removing the enclosure from the truck. Going through two layers of sheet steel with the 4″ hole saw did exercise the drill. After the first hole it was warm enough (130 F) that I decided to give the drill a cool-down period before drilling the second hole.

The relatively small fans on the chargers will hold a piece of paper against the intake openings, so the ducts are working as intended and are definitely pulling outside air into the box to cool the chargers.   It was 100 F today and the chargers didn’t overheat in my short 1 hour test, but I will need to drive the truck on a long trip to really test them under load for multiple hours of charging at full power. Click here to read the update on effectiveness.

Here is a video of the install process: