Please help improve my current Van system and Expansion to Solar A/C

[eXodus]

My Current Setup

So this is my current Van-Setup. Working very nice for 4 years now. Yes I got redundant PSW charge controllers (Amazon send me two when I ordered one), my panels are angled different direction and I got the feeling that with one controller per panel it's harvesting more.

The 200A relay is switched on when the engine runs and I got a switch to manual trigger it- to jump-start myself in case the Starter Batteries dies.

Now I want to run my Window A/C over night. - which needs about 1500-2200wh per night.


So one idea I had, was just adding a bunch more lead batteries. Further I got enough space to add another 2x 100 or 120w solar panels to my roof.
Going from 200w to a total of 440W. I drive every other day, so the alternator is my primary means of charging.

The other idea is replace the Golf Cart batteries with some sort of Lithium. Yet it would probably mean that I have to change almost everything else too?

 

[MisterSandals]

So one idea I had, was just adding a bunch more lead batteries.

If your existing batteries are a couple years old, you cannot (well, should not) add dissimilar batteries to the bank. The stronger batteries will cannibalize the weaker ones. But a bigger battery bank is what you need to store the 1500-2200wh you need.

And if you went with a lithium based battery pack, you would need SCC's that are able to charge them. The blue cheapies do not.

You will also likely need a DC-DC charger between your alternator and lithium battery bank. I wonder what "folks who know" think about running directly off the alternator with your existing setup. I guess it depends on what is controlling the 200A relay.

 

[eXodus]

If your existing batteries are a couple years old, you cannot (well, should not) add dissimilar batteries to the bank. The stronger batteries will cannibalize the weaker ones. But a bigger battery bank is what you need to store the 1500-2200wh you need.

And if you went with a lithium based battery pack, you would need SCC's that are able to charge them. The blue cheapies do not.

You will also likely need a DC-DC charger between your alternator and lithium battery bank. I wonder what "folks who know" think about running directly off the alternator with your existing setup. I guess it depends on what is controlling the 200A relay.

Thanks!

I would replace my existing two lead batteries and buy a whole new set of 6 Golf Cart batteries - which is about $600-700 for 675ah @ 12V which are roughly 8kwh - where I can use 4kwH to get almost 1200 cycles from the set. Or use 6kwh (75% DOD) and sitll get 700-800 cycles.

I use the Van about 60-90 days a year, so the batteries will die of old age before I ever have the chance to kill them with cycles.

 

[MisterSandals]

Here is a thread that beats this horse quite a bit. In particular, ghostwriter66 has a lot of experience with what you are trying to do:

DC powered Mini Split Air Conditioning system

Actually, that is for the AC couples option equipped system. This will be an all dc 48V unit. https://www.hotspotenergy.com/DC-air-conditioner/ IF you would read it, you would find that AC connection is optional.

diysolarforum.com

 

[eXodus]

Here is a thread that beats this horse quite a bit. In particular, ghostwriter66 has a lot of experience with what you are trying to do:

Thanks! I can already run the Window A/C with my current Setup - no issue - it's just sucking the batteries down after 2-3 hours. (not empty but the inverter likes to have them over 12.3V to handle the surge of the Compressor)

The 200A relay is switched on when the engine runs and I got a switch to to Manuel trigger it- to jump-start myself in case the Engine Batteries dies.

 

[eXodus]

Any recommendations regarding what Lithium would be a good drop in for my system?

What would I have to switch?
- MPPT Charge Controller
- DC-DC charger for the Alternator

 

[MisterSandals]

Any recommendations regarding what Lithium would be a good drop in for my system?

Sorry i do not have experience with drop ins or DC-DC other than my RV’s PD4645 (also takes shore power).

I would check the Victron Orion line. Better yet, start a thread for these specific questions (after you exhaust your use of the search feature of course).

 

[MisterSandals]

Here is a thread that might help:

What do you think of this Setup? Kisae Abso MPPT/DC-DC based

So I've got the Xuba 280ah cells and all of the components for my camper van, I just need to hook it all up! Here is the schematic I came with using Will's guide with Renogy DC-DC/Solar 50a system, but I've replaced the MPPT/DC-DC with a Kisae Abso DMT1250. The reasons why I chose the Kisae is...

diysolarforum.com

 

[eXodus]

A/C	6000 BTU		Temperature					Chevy Express 3500 High Top
	Date	Wh	Outside day	Outside night	A/C F setting	Reflectix	Econ	Fridge
7pm - 7am	22-Jul​	2460​	89​	74​	74​	0​	0​	0​
	25-Jul​	1780​	92​	75​	74​	0​	0​	0​
	26-Jul​	2550​	91​	74​	74​	0​	0​	1​
	28-Jul​	2350​	93​	75​	78​	1​	0​	1​
	29-Jul​	770​	93​	75​	78​	1​	1​	1​
	30-Jul​	680​	93​	74​	78​	1​	1​	1​
7am-7pm	30-Jul​	3630​	93​	74​	78​	1​	1​	1​
	26-Jul​	5820​	91​	74​	74​	0​	1​	1​

Was trying to figure, how much power I really need to run the A/C in the Summer in South Florida.
Played around with Reflectix on the Windows. Which helps big time during the day.

Was very surprised to learn, that 74 vs 78 degree doesn't make that much difference during the Night (100wh)
That the Econ Setting on my A/C makes a freaking huge difference - it drops over 1000wh for 12hrs

My dorm fridge needs about 200wh a night.

I'm not that often in the Van during the day, but I want to sleep comfortable.