Passive cooling ?

[rnlcarlov]

So, obviously leaving the key on all night every night and supplementing the 12 volt system with a battery charger is not a long term solution but the data from doing it leads to one.

I did that all night ventilation on my wife’s car and it had an uncharacteristically long charge cycle needing 12 bars replaced instead of the usual 4 or 5! So a longer charging cycle working against the ambient air pack cooling, and a hotter start than the previous night. Still the morning departure temperature for the battery was 87 F, down from the previous 95 F without intervention and only a 4 bar recharge. The cabin blower can work well for this if it is run at mid speed and no higher. Doing so with the key on isn’t practical since it runs a bunch of other systems (unnecessary wear and tear) pulling more than 7 amps total.

7 Amps? Measured where? If I check Canion when car is in ACC, the current draw is around 1-2 Amps.

 

[Aerowhatt]

The cabin blower can work well for this if it is run at mid speed and no higher. Doing so with the key on isn’t practical since it runs a bunch of other systems (unnecessary wear and tear) pulling more than 7 amps total.

7 Amps? Measured where? If I check Canion when car is in ACC, the current draw is around 1-2 Amps.

Sorry, the reading was taken at the 12 volt battery With the key on (not in ready mode) and not charging. In other words that's what it pulls to have the key on from the 12 volt system, not the high voltage system. That's why if you leave the key on (not in ready mode) the 12 volt battery only holds up for about 3 hours. About 100 watts compared with about 15 watts for the cabin fan itself. So leaving the key on is a very wasteful way to go about it.

Aerowhatt

 

[rnlcarlov]

I don't know if this happens in all cars, but in mine I noticed that if you leave you car charging with the key on and the blower on midspeed, it doesn't stop charging. It just stays at 99.5% with the fan blowing. Since at that soc the charging speed is so low, the power going into the car evens out the power being used. Therefore, I think there's really no problem of letting the 12V run out, since it's always being charged by the HV system. Of course, this way is more wasteful that the method you're trying to do, but at least it seems that anyone can do it without any sort of modification, if the need arises.
Or at least I hope so. I someone else would test it in their cars it would be helpful.