Off-Road Camper Solar build...

I'm going to start this with a basic diagram of the electrical system I'm working with. The vehicle I'm working with is a CUCV M1010 which was a military field ambulance. It came with two alternators to begin with but the originals were both 24v and used a terrible system to try to regulate 12v, it always failed. It is currently outfitted with 12v 160a alternators which has proven to be a extremely reliable solution.

I am utilizing the wiring a power distribution panel which was rated at 200a in the back of the truck. All of the fuse numbers are what the circuit is rated at, not the actual draw. The Anderson plug was a separate circuit as well that was rated at 60 amps which I am using to essentially to feed the panel for solar. Yes AC is listed, it currently uses an engine driven compressor so only utilized when the engine is running in current set up. Would I like to change that, possibly but that's down the road, and a long discussion. The air compressor is a similar thing, mainly utilized with the engine running but a just in case on battery, 24v for less load.

Things I currently have:
280Ah cells from Xuba- ordered
Blue Sea ACR 7623
200a circuit breaker

Needed:
BMS
Solar Panels- been looking at 110 and 170 Sunpower panels for weight and clearance on the roof but I know the thoughts on flexible panels- up for consideration
Charge Controller- plan was 4 panels, 2 in series for voltage then parallel into the controller
Inverter- I am trying to do as little with one as possible so I don't plan on a large one. Not on the diagram...
24v to 12v buck converter- probably for stereo, not sure what else

Things needing power: Fridge, Roof Fan, Stereo, Laptop, Phone charger, Heater, TV, all LED lights

Looking for simple reliability. Open to discussions...

John

With all my studying, it looks like my BlueSea ACR will not work as intended and a DC to DC charger will be necessary. Can anyone share their experience with the Sterling DC to DC chargers.

Sterling makes some nice units but a little pricey. Here is the solar controller I am looking to go with. Fully programmable, will take up to 50v solar input.


This is 12v but I think they make a 24v 30amp unit, per the user manual info.

chevymike said:

Sterling makes some nice units but a little pricey. Here is the solar controller I am looking to go with. Fully programmable, will take up to 50v solar input.

KISAE DMT1250 Abso 50A DC-DC Battery Charger | DonRowe.com

The KISAE DMT1250 DC to DC Battery Charger is a multi-stage, multi-input battery charger capable of charging different types of batteries commonly installed in boats, RV's, 4WD's and commercial vehicles.

www.donrowe.com

This is 12v but I think they make a 24v 30amp unit, per the user manual info.

Click to expand...

Thanks Mike! I had not found that one. I am unsure of the all in one and that it limits the charging from one or the other source. Because secretly, deep down, I've been looking at a 24v window AC to replace the one in the box... ssshhhhh. . So if the battery was run way down charging from both could be beneficial. This is where the ACR would falter as it can't regulate amps like a DC-DC can.

Mad_Texan said:

Thanks Mike! I had not found that one. I am unsure of the all in one and that it limits the charging from one or the other source. Because secretly, deep down, I've been looking at a 24v window AC to replace the one in the box... ssshhhhh. . So if the battery was run way down charging from both could be beneficial. This is where the ACR would falter as it can't regulate amps like a DC-DC can.

Click to expand...

Yes, it will pull from both, if available to a max of 50amp (for the 12v model).

chevymike said:

Yes, it will pull from both, if available to a max of 50amp (for the 12v model).

Click to expand...

" With two inputs available, the house battery will be charged from either the engine while underway, or via the solar panels when stationary. The process to choose either engine or solar is fully automatic and both functions are controlled from within the unit itself without the need for external relays."

I'm tired but the way I read this is one 'OR' the other controlled automatically to max amperage (24v=30a). What I'm talking of is having say 20a from a mppt and if I need extra I could run the motor with the Sterling providing an additional 35a. I'm not sure that the unit will pull from both at the same time to the max of 50a. For example: mppt@20a + dc-dc@30a = 50a charging. Am I wrong with what I'm saying?!?!? I admit my head wants to explode.... then the BMS debate... ?

My truck charges my camper battery from the alternator and the solar panels at the same time. The solar is wired directly to the battery.

Freep said:

My truck charges my camper battery from the alternator and the solar panels at the same time. The solar is wired directly to the battery.

Click to expand...

Which DC-DC charger are you using?

I'm in the middle of upgrading to lithium and have just installed a Victron Orion-TR 30 AMP. Before that I only had a Blue Sea battery separator. The new Victron is wired directly to the battery, where the Blue sea battery separator would connect to the main positive bus. The MPPT charger is a Victron Smart Solar 100/30

Freep said:

I'm in the middle of upgrading to lithium and have just installed a Victron Orion-TR 30 AMP. Before that I only had a Blue Sea battery separator. The new Victron is wired directly to the battery, where the Blue sea battery separator would connect to the main positive bus. The MPPT charger is a Victron Smart Solar 100/30

Click to expand...

Thanks for the info, I think we are trying to accomplish the same thing. Victron makes DC-DC chargers in a 12/12 and a 24/12 configuration. I'm looking for a 24/24 charger which narrows the market. The one Mike suggested would work but is bundled as a DC-DC charger/ mppt controller. If they were separate as yours will be, there is redundancy in the system if one goes down as well as higher amperage charging if needed.

edited: I rethought my question...

Mad_Texan said:

" With two inputs available, the house battery will be charged from either the engine while underway, or via the solar panels when stationary. The process to choose either engine or solar is fully automatic and both functions are controlled from within the unit itself without the need for external relays."

I'm tired but the way I read this is one 'OR' the other controlled automatically to max amperage (24v=30a). What I'm talking of is having say 20a from a mppt and if I need extra I could run the motor with the Sterling providing an additional 35a. I'm not sure that the unit will pull from both at the same time to the max of 50a. For example: mppt@20a + dc-dc@30a = 50a charging. Am I wrong with what I'm saying?!?!? I admit my head wants to explode.... then the BMS debate... ?

Click to expand...

Yeah, I guess rereading it, it uses one or the other. I must have been thinking of another unit that will do both at once but it reduces the max charge from both inputs down to 25amp each side, instead of allowing the larger available amp input and the secondary one to make up the difference to the max 50amp limit. I guess for what you want to do, it likely will mean two individual units, a MPPT and a DC-DC charger.

Mad_Texan said:

Thanks for the info, I think we are trying to accomplish the same thing. Victron makes DC-DC chargers in a 12/12 and a 24/12 configuration. I'm looking for a 24/24 charger which narrows the market. The one Mike suggested would work but is bundled as a DC-DC charger/ mppt controller. If they were separate as yours will be, there is redundancy in the system if one goes down as well as higher amperage charging if needed.

edited: I rethought my question...

Click to expand...

The Victron Orion-TR Smart Charger 24/24/17 might be what you are looking for. Unless I didn't understand your question

HaldorEE said:

The Victron Orion-TR Smart Charger 24/24/17 might be what you are looking for. Unless I didn't understand your question

Click to expand...

Thanks! It is what I'm talking about! Victron seems to bury some of their models and info. Looking at the specs it is rated at 17a continuous with a peak of 25a. The manual says you can stack them to get desired amperage needed but they are $263. It still has me leaning towards the Sterling with a 35a continuous and 40a peak which I've found for a little over $400.

I'm disappointed with my Orion TR Smart Charger, I thought it would have VE Smart networking like the MPPT controller but it doesn't.

Freep said:

I'm disappointed with my Orion TR Smart Charger, I thought it would have VE Smart networking like the MPPT controller but it doesn't.

Click to expand...

So no ability to disable charging when BMV or smart battery sense reports say... 0*F?

hour said:

So no ability to disable charging when BMV or smart battery sense reports say... 0*F?

Click to expand...

Not from the Orion. The BMS has a low temp shutoff. I was hoping the MPPT and the Orion would work together along with the Victron temp sensor for optimum charging.

Freep said:

Not from the Orion. The BMS has a low temp shutoff. I was hoping the MPPT and the Orion would work together along with the Victron temp sensor for optimum charging.

Click to expand...

Yeah, me too. Looks like I'll be relying on my BMS to do temperature protection too. Thankfully the box is self heating but I do wonder about voltage sensing. Not that it ever worked great on the BMV->MPPT... in fact it has never worked in a way that makes any logical sense-many posts on victron boards. I was still banking on that functionality at least, as I don't plan on having a perfect charging setup with the Orion mounted as close to the battery as possible and with a direct connection. Was going to do Orion->Power Pole->Power Pole->Blue Sea fuse panel inside battery box->Battery. I'll have to do some heavy testing to try and hit my 13.8v target.

Finally getting around to building my battery and box...

hour said:

So no ability to disable charging when BMV or smart battery sense reports say... 0*F?

Click to expand...

Use a BMV-712 relay output to the control input on the Orion-TR.

Mad_Texan said:

Finally getting around to building my battery and box...

Click to expand...

How heavy is that monster. I broke my battery into two 4 cell packs cause I didn't want to have to pick the whole thing up at once.