I'm all for best practices but i think there is line in the sand where it becomes detrimental if it just dissuades people from ever trying anything in the first place.
Example: I have 220ah of 12v lifepo4 in my ~23' RV. Just yesterday I cut a quick and dirty nasty hole through the back wall and shoved a used 5000btu window AC in the hole. You can see plenty of daylight around it, but i figured this was just for testing until i put a more efficient unit in a slightly enlarged (and cleaner) version of the hole.
I don't know what SOC the lithium bank was at, but i know it was low because i typically pull 1.6-1.8kwh (out of 2.6kwh nominal capacity) out of it overnight on a daily basis supplementing my house system and recharge from solar during the day. I stopped charging it at noon when it normally doesn't finish charging til ~7pm on a 10a-7pm charging window. Sorry I don't have better info, but oh well.
Anyway, whatever charge that was, powered that 5000btu ac from midnight to 5am this morning before hitting the 11.0v cutoff i have setup on the lithium.
That certainly suggests that if the lithium bank were fully charged, it would have run that AC for my entire sleep period. I was comfortable when the ac was running, although i don't know the temp setpoint because it just has a thermostat numbered ~1-8 or something like that. I was in Port Aransas TX a half mile from the coast, so the temperature never drops below 80 and humidity about the same, in the middle of the night. There were 2 adults and 2 children in the RV.
So that's a lot of vague anecdotal stuff but it still suggests that if you are trying to do something like run an AC to keep yourself cool overnight in a large-ish vehicle in a hot/humid climate, you can still
easily do that without a huge battery bank, or a particularly efficient AC, or particularly good
anything! Got less than 4 people? Smaller than a class b RV? More efficient than a $125 special window unit? Well then your case will be BETTER.
Yes, that's different than keeping the same vehicle cool, without touching the batteries, totally off solar, in the daytime. But it's arguably also more relevant to more people. Of course i still want to talk about all of it, coatings, insulation, CEER, pv, etc etc but i just feel we should careful of using so many words to amount to 'it's impractical' and instead sort of couch things in 'how to make it the least bad'.
