I've been driving around with the cover off in the back exposing the HVB exhaust vent. When I'm charging if I'm in the car or if its in my garage I open the tailgate to let the heat out. I can actually charge and lower the car's HVB temp while charging. I found that using the slowest possible charger helps if trying to do this. As the battery gets less amps put into it and takes longer charging hence allows the cooling fan to run longer.
I have 3 chargers available to me.
1) 120v 10 amp, charges at 1180w and puts in around 2.8 to 3.1 amps into the battery.
2) 120v 12 amp, charges at 1380w and puts in around 3.5 to 3.8 amps into the battery.
3) 240v on the road, charges at 8.2 to 9.9 amps or there abouts depending on the station.
On the road I use the fast 240v charger. At home I use the faster 120v charger if I need to charge quicker to go out, and the slower one if I need to take my time or cool the battery for a longer period of time before unplugging it. (like getting home on empty with a hot battery, plug it in with the slow charger and charge it to 20% and then unplug it to rest).
I'm still under the impression that the battery cools better with the cover off. Just from feel and experience both ways.
I read you guys want to put other fans to shove some air down the intakes, but do you realize that the HVB cooling fan can run at several speeds? I Slow is 1000 rpms, but as you drive faster and faster I've seen it go up as fast as 2125 rpms IIRC. What about just running a 12v wire to the fan directly and being able to switch it on yourself any time you need it, rather than wait for it to wait until the temp differential is 7 degrees plus before it kicks in? Also if you had the "full voltage" I suppose you can run it at max speed all the time.
What are the thoughts about that?