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3 hours and 19 minutes of cool for all that money! Plus it's not really running of solar as a second alternator had to be installed! We got a ways to go.
 

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That's only about 5 kWh of battery capacity. If you got serious money, just add a lot more. :rolleyes:

Electric cars like Tesla and others already have enough battery capacity to run A/C for long periods. With 85 kWh of battery capacity you could run RV A/C for a couple of days. Just takes more money than it makes sense to spend.

I think we'll be close to economic reality when vans adopt 48-Volt mild hybrid system to improve fuel economy. With 48-Volt alternators in range of 10 to 20 kW, the engine will only have to run a small percentage of time to recharge lithium batteries. And with any luck the vehicle's OEM electric A/C will even be able to cool the van without having to install a roof air conditioner. We'll need much larger batteries than mild hybrids come with though.
 

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"If you've got the money" says it all!.

It sounds as if this was only possible because of extensive help from all the corporate interests involved. It reads like one big sales promotion to me. Lots of great, unaffordable, unrealistic engineering and help NOT available to the typical peon (us).

A good read, however, to see what can be done if you throw enough money at something. I think the future is going to be in Telsa "battery packs" making much of this exercise outdated and overly complicated.

Considering the time and money expended on this project to gain under four hours of AC I would stick with a genset or travel in better climates! ;)

A good read tho.
 

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Yes I think this was just a sales pitch for these companies. He obviously got help that no one else would have with all this.
 

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They had a perfectly good generator and removed it.
I wouldn't say perfectly good, I dislike generators, they are way too loud. But to each their own.

This is a decent system and I believe there is a user or two on here that did the same. Honestly the hardest part about this setup is the regulator on the second alternator. The main issue with AC on battery is battery capacity. It's just too expensive and not enough power to make it worth doing for most people. RZ said it best with all that money for only 3 hours. I think their idea was to run AC while at a bike race (I think james races and his wife will wait in the rig and needs AC if it's too hot). While it works for them, it won't work for a lot of people that have these ideas of endless AC. 400ah lithium battery is pretty large physically. Double that for 6-7 hours and that's a lot of physical size and weight and still won't get you though a night of sleeping with AC on.

I gave up my dream of AC on battery a long time ago. There just isn't enough room in the van so you might look to installing them under the van. I live in the north east with cold winters. Dealing with charging lithium in the cold is a whole other challenge. You can get battery warmers, but those use a lot of power, plus the BMS to run the lithium it seems like you are using a lot of amps just to heat and run the battery. Not worth it.
 

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They had a perfectly good generator and removed it.
I don't blame them at all if after nearly a year they had only used it about 3 hours -- other than for recommended generator exercise. However, in my opinion other decisions still leave some serious questions.

Firstly, if they only used generator 3 hours in a year, then they are not running their A/C very often without shore power. This being the case, then why add a second alternator? I like the concept of a second dedicated alternator a lot, but its main purpose is to allow for use of lots of power without hookups, with majority of that being for air conditioning. And if you need to run the van's engine that much for air conditioning, why not just run the van's A/C? Granted there are some anti-idling laws, but if you have to idle for second alternator anyway, then it may not circumvent this problem anyway.

Secondly, if you're not going to run A/C for hours at a time (requiring huge battery bank), then why even go to 400 Amp-hours of lithium? Half that would support an inverter to run microwave, coffee maker, fans, pumps, etc.


I like the concept of a second dedicated alternator and large lithium battery bank but only if it's large enough to run A/C at least through the night. If it's only good for three hours, just run vehicle A/C directly off engine, and charge smaller-size batteries from normal alternator. In this case I don't see a lot of merit in their middle-ground design.
 
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