I have a prototype cooling blower mounted in my car and two charges monitored with it. First let's review.
First all of, the numbers are are based on my 80F ambient charging environment. It is reasonable to use these numbers adding or subtracting as needed depending on your ambient charging location temperatures.
As designed the OEM cooling system delivered the following results.
Under L-2 the case temperature peaked at 56F above ambient temp.
Under L-1 (12 amp) the case temperature peaked at 48F above ambient temp.
So charging L-1 only delivered a ~15% decrease in charger temperature rise.
Switching to coolant inlet temperature as the comparison metric.
Under L-2 OEM setup the inlet coolant temperature was 113F (33F above ambient)
With 50 CFM of ambient air blowing directly through the radiator this was reduced to 104.4F (charger case still too hot to hold on to)
With 25 CFM strategically blowing on the charger case, the case (nothing on the radiator) the coolant temp reduced to 99F (19F above ambient) (charger case easily held on all sides and top).
The prototype is a single Nidec Gama 30 blower strategically placed in the motor bay. As a prototype the the bracket is pretty ugly, but that's why we prototype. Nothing like doing it to show one what needs improved. Like the prototype bracket, the final version will require no drilling of the car whatsoever, and will be fairly easy to remove and reinstalled should a warranty trip to the dealer come up. Even with the hatch lid completely installed and the sound insulation, etc., plus all the junk I keep in the trunk
. I'm getting the same temps as I did in the cover open - blower cooling the charger trials.
Funny how realizing your >$4,000 charger/DC-DC is running uncomfortably hot motivates one to get things done. I plain didn't want to charge again without a solution in place. Wife always get nervous when I'm working in the garage late into the night