Class B Full lithium No Generator?

[Camerabry]

When we were looking to buy I just couldn’t pull the trigger on lithium pkg yet. No one could tell me I could run the AC and in Florida that’s a must. Hopefully by my next rv it will be there and won’t have to worry about dealing with it in the middle of the night.

 

[TheLooks]

I participated in a $30,000 dollar install at school and it would run the AC. But that is a high price for it.

 

[Rich W.]

The big question is the 12v AC - if it really only uses 900w thats great, you can figure your run time by dividing that into 80% of your battery bank capacity. But one thing to consider is the BTU output of the unit. A 900w AC is probably around 4k btu which might not be sufficient in hot weather, even for the small space of a Class B.

The other thing of course is the battery bank size. My SWAG on the run time for the OP’s 630ah battery bank is around 7 hours with nothing else running. If you are camping in the South, and you stopped at your CG with no hookups around 4pm, you’ll be waking up hot and sweaty before mid-night with no power. Not a good scenario. Also that 220w solar panel is really only a small trickle charger - probably 10amps at best. It wont come close to recharging the battery bank in a day of full sun, which of course will make the coach an oven.

I’d say we are getting closer to systems that can effectively live off lithium batteries, but they are currently way over-priced (IMHO) and not yet sufficient. I’d travel with a small (~2000w) quiet generator as a back-up or plan to have hook-ups. @Camerabry, why they couldn’t answer the question.

 

[Rich W.]

I participated in a $30,000 dollar install at school and it would run the AC. But that is a high price for it.

I built a system with 2/3 of a Nissan Leaf battery (gen 2) and 1890w of solar, and it would run a 15k btu AC for about 8 hours after sundown. Around midnight in Memphis in September, so not even sufficient. That system cost me around $8,000 but that was before people discovered used Leaf batteries (from wrecks) and now they are really hard to come by.

Building a system that will run an AC through the night doing everything myself and finding a deal on the battery would now probably cost nearly double that, and with solar, you have to park in the sun which kind of defeats the purpose. Without solar, I could see it running towards that $30k mark.

The good news is that Leaf batteries are now in gen 4 and the capacity is more than double the gen 1 (I think around 60kwh). So if you can find a deal on a good used gen 3 battery (lowish milage car from a northern climate) and you have the skills, you can build a very capable system, but it isnt plug-and-play like LiFePO4, and you need a 3kw inverter for one AC. You can see how it adds up fast.

This is my battery from my install in my Bay Star. I’ve since repurposed it to run my 48v Polaris EV:

 

[TheLooks]

This one had $14,000 in batteries and the rest was Victron dual inverters and all the bells and whistles plus I think just under 3000 watts of panels on the roof. But I am to old to recover the cost of that.

 

[Rich W.]

This one had $14,000 in batteries and the rest was Victron dual inverters and all the bells and whistles plus I think just under 3000 watts of panels on the roof. But I am to old to recover the cost of that.

I’ve decided its more of an expensive hobby or accomplishment or whatever to run ACs off solar/batteries than a worthwhile investment, and moved on to other pursuits. And not camping in the South in the summer makes a big difference.

My “dream system” that I have since abandoned included about 20kwh of Leaf modules, and a Victron 8kw 48v inverter, but staying with my current 1575w of solar due to small roof area. Either that or buy a bigger coach too!

But that would also mean abandoning all the Magnum components in the coach, just so I could camp where I really don’t want to anyway. If I have to go where I need AC, I’ll just visit CGs with hook-ups.

 

[Kevin D Pem]

The big question is the 12v AC - if it really only uses 900w thats great, you can figure your run time by dividing that into 80% of your battery bank capacity. But one thing to consider is the BTU output of the unit. A 900w AC is probably around 4k btu which might not be sufficient in hot weather, even for the small space of a Class B.

The other thing of course is the battery bank size. My SWAG on the run time for the OP’s 630ah battery bank is around 7 hours with nothing else running. If you are camping in the South, and you stopped at your CG with no hookups around 4pm, you’ll be waking up hot and sweaty before mid-night with no power. Not a good scenario. Also that 220w solar panel is really only a small trickle charger - probably 10amps at best. It wont come close to recharging the battery bank in a day of full sun, which of course will make the coach an oven.

I’d say we are getting closer to systems that can effectively live off lithium batteries, but they are currently way over-priced (IMHO) and not yet sufficient. I’d travel with a small (~2000w) quiet generator as a back-up or plan to have hook-ups. @Camerabry, why they couldn’t answer the question.

Lithium Batteries are not power producers, they are power storage!!! This will never change! You will only be able to take out of the store what has been delivered. If you have learned anything the last few years it should be, if the supply chain breaks down, you have nothing.

That said, if the store is big, with not to many demands, it will be longer before the supply needs replenishment.

The supply must be large enough to supply demands + shrinkage. This can be from vehicle generation, solar, or portable generator. The caution I will voice is automotive generators are not designed to charge deeply cycled battery banks, so they fail in short time when used for that purpose.

 

[Rich W.]

Lithium Batteries are not power producers, they are power storage!!! This will never change! You will only be able to take out of the store what has been delivered. If you have learned anything the last few years it should be, if the supply chain breaks down, you have nothing.

That said, if the store is big, with not to many demands, it will be longer before the supply needs replenishment.

The supply must be large enough to supply demands + shrinkage. This can be from vehicle generation, solar, or portable generator. The caution I will voice is automotive generators are not designed to charge deeply cycled battery banks, so they fail in short time when used for that purpose.

One of the big manufacturers, Thor I think, recently unveiled a coach with a big (40kwh or so IIRC) lithium battery bank and no solar or generator. They could have done with a conversation with @Kevin D Pem beforehand because they really missed the point. Its nice to have a big battery bank that runs everything, but you have to make regular deposits to use use it or you’ll be in overdraft which doesn't work. And the penalty is that you don’t have the power when you need it.

As I stated above, progress is being made, but we arent there yet, because while its possible to design and build a big, capable system, it’s not at all cost effective, will never pay for itself, and as of now it pretty much just an expensive hobby. And I already have some of those.