Reviving a Duosida EVSE with water ingress

My Duosida charger (16A/3.8kW) wouldn’t charge my eGolf this afternoon; I got a flashing red light. I’ve had some trouble with the eGolf charging so I thought it was the car, although the red light was new. In the end, though, my Duosida charger was full of water! It’s advertised as UL ‘rated’ and suitable for use outside with an IP55 ingress rating. Turns out they claim to be ‘UL rated’, but it’s actually just the cord itself that is UL Listed. Either way, outdoor use didn’t work out here. It was outside on the ground on top of leaves, and got snowed on all winter. I had in mind to put it in a box to keep the snow and sun off, but never did. It was displaying a yellow ‘fault’ light at first, but then didn’t turn on at all after I took it to a different outlet to test it, then I felt and heard water sloshing around inside. Uh oh! Not much to lose at this point, so I opened it up.

Water in EVSE - and lots of particulates too. Just from outside, or from all the electrolysis inside?

Top of board is pretty clean

Bottom of board with lots of deposits

Deposits on the PCB after first round of scrubbing with distilled water, an isopropanol rinse, and 24hr drying period

Clean board after scrubbing with contact cleaner and an overnight drying

Note the little dessicant pack in there on reassembly, and the orange seal in the case that is questionable at its job (yes, twisted in this pic)

Where I suspect the water entered: a not-very-tight cable gland on the input

Charges fine! (pre-assembly test)

It behaved normally and charged the car fine for 30 min at full power. I’m going to seal it up better with silicone (especially around the cable glands and screw holes) and put it in a box to keep the weather off from here on out.


I love these kinds of repairs, because you literally can’t make it worse than it was when you started - “completely broken.”

I figured it was worth a shot - stuff like that tends to be pretty robust, just… doesn’t like being wet. :slight_smile: