Meertruck 1124AF

[palebluewanders]

Some notes,

• do you really need 110v charging with a 2kw solar array, DCDC and a generator? Almost everywhere is 220-240v...
• I suppose you have a good plan for a rather large alternator for 3*17@24v DCDC charging?
• Do not wire in your MPPT DC chargers into the starter batteries, they are very differnet charging profiles, you can use a battery connect device to set a trickle charge if needed
• You will need separate cables for MPPT and DCDC chargers, there is a potenial current of almost 150amps at 29 volts there

- We'll likely not have a generator after all, very limited toolbox space and it's not clear we'll need one anyway. It's just in the diagram in case we would like to add one later. And we would like to make it over to North America at some point down the line. Anyway we've since replaced the big Skylla with a much smaller Phoenix charger that goes down to 110v.
- Our alternator is 100A, so 3x17 = 51 would be about half of the alternator capacity. Might upgrade to 150A alternator later, not sure yet. May also get a buck boost instead of the 3 Orions. More research is needed since the buck boost seems to not have the right charging profiles for lithium.
- The MPPT isn't wired into the starter batteries, they'll only charge the house batteries.
- Hm, we were planning to size that cable for the largest current; wouldn't it be fine as one cable in that case? This is the way it's done in some official Victron diagrams as far as we can remember, though it has been about 10 months since we've really thought about the electrical system so it's not very fresh in our mind atm. 😅

 

[Geo.Lander]

Thanks. We will probably stick with Victron for everything, and def spring for the bluetooth versions of the devices that have them. Although we're under the impression that engine and solar charging wouldn't happen at the same time, since the voltage will be high during engine charging and that will make the MPPT think the batteries are full. Is there some way around this that you know of?

Do not mix DCDC charging and mppt imo

 

[Geo.Lander]

- We'll likely not have a generator after all, very limited toolbox space and it's not clear we'll need one anyway. It's just in the diagram in case we would like to add one later. And we would like to make it over to North America at some point down the line. Anyway we've since replaced the big Skylla with a much smaller Phoenix charger that goes down to 110v.
- Our alternator is 100A, so 3x17 = 51 would be about half of the alternator capacity. Might upgrade to 150A alternator later, not sure yet. May also get a buck boost instead of the 3 Orions. More research is needed since the buck boost seems to not have the right charging profiles for lithium.
- The MPPT isn't wired into the starter batteries, they'll only charge the house batteries.
- Hm, we were planning to size that cable for the largest current; wouldn't it be fine as one cable in that case? This is the way it's done in some official Victron diagrams as far as we can remember, though it has been about 10 months since we've really thought about the electrical system so it's not very fresh in our mind atm. 😅

We probably have the same alternator fitted if its an AV job?
51 amps at 24V is a lot for a 100A alternator, remember it has to power the truck electronics too, lights.. When I added up my planned light bar etc and good margin for truck systems it was 29amps I think. And the general rule is the size 50% of total draw of output..

Hopfully victron will come with something better for DCDC charging, it has been on the cards for a while now...

 

[DiploStrat]

Disconnecting one of the two REDARC B2B's seems to help. While it reduces the total potential engine charge to 40A, having only one REDARC connected seems to keep it from dropping to float too soon.

Will keep monitoring. Next option is to reduce the absorb voltage on the Victron from 14.2v to 14.0v and see if that makes a difference.

At this point it appears that the problem is the two REDARC's "seeing" each other.

Last day's drives we appear to have had full charge from the solar and the B2B at the same time.

N.B., This should not be a problem as the absorb voltage on the REDARC is 14.5v, but I can only report what I see.

Driving along I can measure, via Bluetooth, the Victron SmartSolar and the BMS of the battery. So I have to remember that when I am looking at the battery I am looking at net - that is amp flow from all sources reduced by all drains. I typically assume 5 - 10A from the refrigerator, misc. fans, etc.

Thus my recommendation for a system that is all one brand.

 

[palebluewanders]

We probably have the same alternator fitted if its an AV job?
51 amps at 24V is a lot for a 100A alternator, remember it has to power the truck electronics too, lights.. When I added up my planned light bar etc and good margin for truck systems it was 29amps I think. And the general rule is the size 50% of total draw of output..

Hopfully victron will come with something better for DCDC charging, it has been on the cards for a while now...

Very good point about the truck systems, we hadn't calculated/estimated that yet tbh. 😅 But I think we should be able to selectively turn on/off one of the Orions for when we're powering lights and other heavier stuff.

But yeah I think they've fitted one of those 100A ones for us too.

We are off to visit AV again in two weeks!

 

[palebluewanders]

Reunited with our truck after nearly 2 years!


Closeup of the slightly-less-than-1.5-cab:


Good progress on the box too:



We are expecting quotes on the metal fabrications in the next couple of weeks. Hopefully they'll arrive by Feb/March and the rest of AV's work can be finished by end of summer. We'll see.

 

[DiploStrat]

Some random electrical points:

-- This spring, with 4x160w panels and 840Ah of battery, we had to charge about once a month, and one of those probably wasn't really necessary. Now, in the fall, our solar charge has dropped to less than one half what we were getting before. While there is always a chance that there is some other problem, I suspect that the difference is shorter days, but, more importantly, lower sun angle. The sun simply does not get high enough over the panels to get full output.

-- Still wrestling with the problem of the B2B dropping to float too soon, but I can confirm that the Victron SmartSolar and Phoenix chargers seem to play nicely together.

-- Get Atkinson Vos or an electrical specialist to upgrade you to a modern Bosch (or similar) alternator of at least 150A. This will require replacing the pulley on the new alternator and some minor re-wiring to fit the modern plug, but it is worth it. Trust me.

FWIW, we get charging from the engine, through the B2B and the solar all the time. Our problem is that the B2B goes to float after about an hour, no matter what the battery voltage or SOC. Still chasing that one.

 

[joeblack5]

Two years, time flies in overlander projects. I am curious about how your habitat is going to be attached to the frame or subframe, how many bolts, what size washer or international reinforcements, any rubber shock absorbers?

Johan

 

[joeblack5]

Diplostrat, is that 840 ah at 12 or 24 volt?

Johan

 

[palebluewanders]

Some random electrical points:

-- This spring, with 4x160w panels and 840Ah of battery, we had to charge about once a month, and one of those probably wasn't really necessary. Now, in the fall, our solar charge has dropped to less than one half what we were getting before. While there is always a chance that there is some other problem, I suspect that the difference is shorter days, but, more importantly, lower sun angle. The sun simply does not get high enough over the panels to get full output.

-- Still wrestling with the problem of the B2B dropping to float too soon, but I can confirm that the Victron SmartSolar and Phoenix chargers seem to play nicely together.

-- Get Atkinson Vos or an electrical specialist to upgrade you to a modern Bosch (or similar) alternator of at least 150A. This will require replacing the pulley on the new alternator and some minor re-wiring to fit the modern plug, but it is worth it. Trust me.

FWIW, we get charging from the engine, through the B2B and the solar all the time. Our problem is that the B2B goes to float after about an hour, no matter what the battery voltage or SOC. Still chasing that one.

Good data point about the solar, thanks! We may look at having a manual tilting mechanism for the panels, we'll see.

AV have already replaced our alternator with a no-brand 100A one, bummer. But we'll consider saving that as the spare and upgrading to 150A. Did AV install yours?

Best of luck with your B2B!

 

[palebluewanders]

Two years, time flies in overlander projects. I am curious about how your habitat is going to be attached to the frame or subframe, how many bolts, what size washer or international reinforcements, any rubber shock absorbers?

Johan

When thinking about the truck, it feels like we've been waiting ages. But then I'm very surprised every time Nov/Dec roll around and wonder what happened to the year.

The habitat will be attached to the subframe via 16 GRP bolts. I don't think there are any shock absorbers or additional reinforcements.

 

[DiploStrat]

Misc replies:

-- Battery bank is a home brew of 840Ah, made up of 280Ah cells. Actually three 12v batteries in parallel, each with 120A Overkill Solar BMS.

-- I sourced the alternator through Nations Starter and Alternator (https://www.nationsstarteralternator.com/) in the US and replaced it at the garage I use in Centreville, Virginia. Plug was found on eBay. Adam and Holly Nations are wonderful people.

-- Rather than pay for a tilt mechanism, I would use bifacial panels and double deck them with slide outs, a la Everlanders. Fringe benefit, in the summer, the panels shade the sides of your truck.


You don't need to build his fancy air powered system, something manual would be fine.

-- For anyone building on a 24v truck, I strongly recommend building/buying a 24v camper battery - makes everything sooooo much easier. Had I realized the challenges, I would have simply junked the 12v stuff and started over. Would have been less expensive in the long run. Many appliances can be found in 24v and, in the end, a 24v to 12v converter/transformer is easy to find. Given the age of my biggest component, the inverter/charger, I am still sometimes tempted to start over.

If you REALLY want to think different, there is a company that takes a very different approach to all of this: They slap a 2KW inverter on the starter battery and feed 110v to the inverter/charger. Thus they only feed the battery from two sources, the solar controller and the inverter/charger. I would have thought that the losses would be huge, but I am told that they are not. Heat is an issue as both inverters are in the same compartment, but there are many solutions to that.

Basically, instead of paying for a B2B, you simply pay for an inverter and then use the inverter/charger that you already have.

(This plan was made by a customer, but the company confirms that it is close. The interesting part is on the right; ignore the rest.

N.B. You need an ignition controlled switch somewhere in the feed to the inverter, so that it only comes on when the truck is running; otherwise you will kill the starter battery quickly - especially with a big camper battery and a 3Kw inverter/charger!)

 

[palebluewanders]

Quick update: finally painted!



TBH we thought we were picking a slightly more orange color:

But who knows, colors always look different in person, are dependent on the light, etc. Even if it's as yellow as it is in the pic, it's still a nice yellow.

Still waiting on metal fabrications that were ordered in January, I think.

 

[Geo.Lander]

Quick update: finally painted!

View attachment 827793

TBH we thought we were picking a slightly more orange color:

But who knows, colors always look different in person, are dependent on the light, etc. Even if it's as yellow as it is in the pic, it's still a nice yellow.

Still waiting on metal fabrications that were ordered in January, I think.

Gorgeous, that is gonna work super well in deserts and beachside! And bonus, put some yellow flashers on and in the city you will get away with anything
We actually though about re-doing our truck logo to be more militaristic so we could get away with some first impression traffic upsets in and around towns