Mies - an ARV 2500 144 WB 2WD Van

[booster]

Originally Posted by RT-NY

The more I research this question, the more this seems to me like the best solution for RV power: no solar, no generator, just a high capacity lithium battery bank and a high output alternator. What kind of DC to DC charger does ARV use to put 275 amps (!) into the battery bank? Most of the commericially available chargers that I have seen do not go beyond 60A.

I say that this is the best solution, but it is not necessarily the most practical or cost effective! What I am wondering is how feasible is it to upgrade a vintage RV to this kind of setup. It is easy enough to remove the Onan generator and install a few LifePO4 batteries. But is it practicable to install enough alternator capacity, heavy duty wiring, and B2B charging capacity? Easier on an older RV is a 40a setup but that means much more driving and so less benefit over generator or solar charging.

So my two questions:

1, What is the highest capacity commercially available B2B charger?

2. What the upper limit in terms of charging amps, practicably and without inordinate expense, of an alternator based charging system on a vintage Dodge (or similar) RV?

The ARV would have a standalone second alternator on it's own regulator so no B to B charger needed.


I would "mostly" agree with the big alternator being the best alternative for a lot of the charging, but personally I would also want a way to stay offgrid without running the engine if I chose to. I would have some sort of fuel powered heat, cooking, and hot water heating be it propane or engine fuel (gas or diesel). I do like propane for it's more trouble free operation, I think. For charging at reduced consumption, as much solar as possible and then match use to what the solar will do.



I think many of the big battery bank units are allowing too much parasitic loss and high load everyday functions like an induction cooktop or electric water heater. This makes engine charging necessary regularly if you use them and want to stay offgrid. Again, just my preference, but I would not do it that way for the way we would use such a van.

[RT-NY]

Originally Posted by RT-NY

So my two questions:

1, What is the highest capacity commercially available B2B charger?

2. What the upper limit in terms of charging amps, practicably and without inordinate expense, of an alternator based charging system on a vintage Dodge (or similar) RV?

Originally Posted by booster

I would "mostly" agree with the big alternator being the best alternative for a lot of the charging, but personally I would also want a way to stay offgrid without running the engine if I chose to.

I agree. My questions were less about alternator charging versus other forms of "power" (I would not want to do away with the propane in my RV), and more about what the practical limits are on upgrading an existing charging setup to a high capacity alternator based setup.

[Davydd]

Don’t get me wrong as it is not that simple,I’m describing the Lamborghini of Class B systems and there is a lot of development technology behind it. I was willing to pay for it as well as a totally custom Class B. It is not an off the shelf solution. At least I don’t think it is.

It is a second alternator, not the chassis alternator that can only deliver 60a. The Delco is a huge alternator that i doubt could fit under the hood other than a Sprinter. I know it could not fit in a Promaster but there are other solutions such as a smaller Nations alternator of which their are off the shelf solutions. The Delco is installed with Custom brackets and belts developed by ARV. As to how it can deliver 275 - 330 amps a 4.0 stranded copper wire would do it. That’s nearly 1/2” diameter.

All in all it is rather expensive but a standard for ARV. If you wanted to install such a system in a vintage Dodge you might exceed the cost of the van. And I doubt a DIY solution could equal it unless you are an experienced electrical genius which by your questions you don’t appear to be. I’m not an electrical genius either. I just describe what I paid professionals for and they’ve said I’ve got some the details wrong in my comments.

[booster]

Originally Posted by RT-NY

I agree. My questions were less about alternator charging versus other forms of "power" (I would not want to do away with the propane in my RV), and more about what the practical limits are on upgrading an existing charging setup to a high capacity alternator based setup.

I think it all depends on how big you want to go and what you are starting with. We did a parallel two alternator system because the PCM in the van (2007 Chevy) did not control the alternator. Two high output alternators on their own remote regulator. 550 amps so we run them at under 50% to keep cool and it works very well for us. On a big battery bank a high output single alternator may still be at too high an output for good life, so you have to be a bit careful, but on a remote regulator like a Balmar, you can reduce the output maximum. Of course, the wiring usually needs to be upgraded for high charge rate systems.

[Davydd]

Originally Posted by booster

The ARV would have a standalone second alternator on it's own regulator so no B to B charger needed.


I would "mostly" agree with the big alternator being the best alternative for a lot of the charging, but personally I would also want a way to stay offgrid without running the engine if I chose to. I would have some sort of fuel powered heat, cooking, and hot water heating be it propane or engine fuel (gas or diesel). I do like propane for it's more trouble free operation, I think. For charging at reduced consumption, as much solar as possible and then match use to what the solar will do.



I think many of the big battery bank units are allowing too much parasitic loss and high load everyday functions like an induction cooktop or electric water heater. This makes engine charging necessary regularly if you use them and want to stay offgrid. Again, just my preference, but I would not do it that way for the way we would use such a van.

With a big battery bank as you say negates running an engine or for that matter a noisy generator while boondocking. As for water heating and cabin heat, it is done off the engine’s fuel system (diesel in my case) not electrical and without running an engine. If you have a big battery bank, no amount of solar on a Class B will appreciably keep your batteries charged and if you have a big battery bank say of 800ah you can go about 5 days boondocking and cooking without solar. As I mentioned before, I cut down my battery amp hours because I seldom stay in one place without driving after two nights. I was just in Yellowstone last week and put 300 miles just in the park. You can’t help going back to your campground without 100% batteries and who gets solar after dark?

[RT-NY]

Originally Posted by RT-NY

So my two questions:

1, What is the highest capacity commercially available B2B charger?

2. What the upper limit in terms of charging amps, practicably and without inordinate expense, of an alternator based charging system on a vintage Dodge (or similar) RV?

Originally Posted by booster

I think it all depends on how big you want to go and what you are starting with. We did a parallel two alternator system because the PCM in the van (2007 Chevy) did not control the alternator. Two high output alternators on their own remote regulator. 550 amps so we run them at under 50% to keep cool and it works very well for us. On a big battery bank a high output single alternator may still be at too high an output for good life, so you have to be a bit careful, but on a remote regulator like a Balmar, you can reduce the output maximum. Of course, the wiring usually needs to be upgraded for high charge rate systems.

OK - so it sounds like if someone wanted to exceed the 40-60amp range for charging, they would need a second alternator with its own regulator and new wiring of sufficient gauge run back to the battery bank. Could an existing 2000 era Dodge RV be updgraded in such a fashion to make possible 120amps of charging at anything near a reasonable cost?

[booster]

Originally Posted by RT-NY

OK - so it sounds like if someone wanted to exceed the 40-60amp range for charging, they would need a second alternator with its own regulator and new wiring of sufficient gauge run back to the battery bank. Could an existing 2000 era Dodge RV be updgraded in such a fashion to make possible 120amps of charging at anything near a reasonable cost?

Others here would know better about the availability of second alternator kits, usually from Nations, but if they are available, yes, 120 amps is not a big deal if the batteries can handle that much input. We are currently set at about 120 amps at low output and 180 amps at high output on our setup. If no second alternator is available, a big 280 amp or so single with current limiting on it would also work as long as it didn't interfere with ECM control on the Dodge ( I think they make an ECM elimination kit for that, though).

[booster]

Originally Posted by Davydd

With a big battery bank as you say negates running an engine or for that matter a noisy generator while boondocking. As for water heating and cabin heat, it is done off the engine’s fuel system (diesel in my case) not electrical and without running an engine. If you have a big battery bank, no amount of solar on a Class B will appreciably keep your batteries charged and if you have a big battery bank say of 800ah you can go about 5 days boondocking and cooking without solar. As I mentioned before, I cut down my battery amp hours because I seldom stay in one place without driving after two nights. I was just in Yellowstone last week and put 300 miles just in the park. You can’t help going back to your campground without 100% batteries and who gets solar after dark?

I think you are trying to stuff our preferences into your system that was designed for your preferences, so of course it doesn't work that way 100%. You have the heat and hot water on van fuel as I would desire so that is fine, but you still have higher load stuff for cooking and maybe parasitics that I would not want. Close but not complete there for our style as you have mentioned 2-3 days max without driving limitations.



What you missed, I think, was the statement about being ABLE to reasonably reduce needed power requirements to make the solar available capable enough to keep you offgrid for long periods, which I think is a very reasonable thing to be able to achieve. We can do that now on 440ah of AGM, so on a bigger lithium bank it should be easy to do if desired. We have 300 watts of solar and I think many vans could get 4-500 watts so more power available. Our parasitic is only .4 amps or a bit under 10ah per day.

[avanti]

Originally Posted by RT-NY

What is the highest capacity commercially available B2B charger?

If used to charge lithium batteries, many B2Bs (e.g. Sterling) can be used in parallel, so there is no practical limit to current you can push, assuming you can generate it. My next rig is going to be a Ford Transit. With the OEM dual alternators, they permit upfitters to take off 235A (although the energy management system has load-shedding protocols that must be adhered to). Most people are using several Sterling B2Bs in parallel with this source. Some people simply directly drive high-capacity inverters, which they feed to shore-power inputs of their chargers.

As for upgrades of older vans, Nations Alternator sells high-capacity alternators for many older vehicles, typically 180 amps, but they have an exotic line of units that go up to 370 Amps in some cases. How you manage belt life with them, I do not know.

I think that "electrical genius" is a bit of an exaggeration, but electrical literacy is certainly called for in a DIY project. ARV certainly deserves credit for being one of the pioneers in high-capacity batteries in B-vans, and for freely sharing what they have learned. That said, though, the world has caught up and there are many straightforward approaches that are nearly cookbook these days.

[RT-NY]

Originally Posted by avanti

If used to charge lithium batteries, many B2Bs (e.g. Sterling) can be used in parallel, so there is no practical limit to current you can push, assuming you can generate it.

As for upgrades of older vans, Nations Alternator sells high-capacity alternators for many older vehicles, typically 180 amps, but they have an exotic line of units that go up to 370 Amps in some cases. How you manage belt life with them, I do not know.

I think that "electrical genius" is a bit of an exaggeration, but electrical literacy is certainly called for in a DIY project. ARV certainly deserves credit for being one of the pioneers in high-capacity batteries in B-vans, and for freely sharing what they have learned. That said, though, the world has caught up and there are many straightforward approaches that are nearly cookbook these days.

That's interesting about using B2B chargers in parallel. And it looks like Nations makes a 370 amp alterator for the older Dodge vans; but you mention belt issues, and it sounds like there are potentional conflicts with the car's electrical system with output that high, which would need to be addressed/bypassed. In any case, from the responses so far, it looks like the answer to my original question is that 120-160amps might be doable at a cost of $2,000.00 - $3,000.00 or so, though it would require some expertise to pull off.

[avanti]

Originally Posted by RT-NY

but you mention belt issues,

That was pure speculation on my part. It would be a lot of torque, though.

and it sounds like there are potentional conflicts with the car's electrical system with output that high, which would need to be addressed/bypassed.

I wonder if dual alternators would be practical on your rig. The Nations' guys are friendly and knowledgable. You might want to give them a call.

[Davydd]

Originally Posted by booster

I think you are trying to stuff our preferences into your system that was designed for your preferences, so of course it doesn't work that way 100%. You have the heat and hot water on van fuel as I would desire so that is fine, but you still have higher load stuff for cooking and maybe parasitics that I would not want. Close but not complete there for our style as you have mentioned 2-3 days max without driving limitations.



What you missed, I think, was the statement about being ABLE to reasonably reduce needed power requirements to make the solar available capable enough to keep you offgrid for long periods, which I think is a very reasonable thing to be able to achieve. We can do that now on 440ah of AGM, so on a bigger lithium bank it should be easy to do if desired. We have 300 watts of solar and I think many vans could get 4-500 watts so more power available. Our parasitic is only .4 amps or a bit under 10ah per day.

I think you are trying to dismiss the advantages of lithium based on your lack of experience with lithium and bringing up the failures of the old Roadtrek eTreks with the parasitics and needing to run you engine in a campground crap.

I’ve had 460 watts of solar and know the little contribution it makes to an 800ah battery pack. I could have driven a few minutes to equal the contribution.

What is the matter with higher electrical loads for cooking such as induction cooktops, Instant Pots, convection ovens and Keurig coffee makers always available? They are kind of nice to have. Maybe if you boondocked with the same electrically advantages of shore power without the husbanding of your batteries you would love it.

Trust me, not having an Onan generator and propane is a blessing. I’d rather have a second alternator than another fossil fuel internal combustion engine. On a short Sprinter I could only get about 100 watts of solar instead of two skylights, a Maxxfan, air conditioner and an automatic Rayzar dome antenna. Underneath, I’m enjoying my 91 gallon capacity in Fresh, grey and black tanks instead of a propane tank and an Onan generator.

AGM batteries (too heavy and too large to obtain equal capacity), propane and Onan generators are old school. Besides it would have been impossible to design a 2500 short Sprinter with the amenities and capacity I achieved with them, which, BTW is the subject of this thread.

[avanti]

I am very much on the fence concerning whether to bother with solar next time around. I agree that (at least for our usage pattern) it adds insignificantly to boondocking time. That has always been my position. But, there are two reasons why I am still considering modest solar:

1) Raised solar panels on the roof comprise "portable shade". There is no doubt that they contribute significantly to cool interiors during periods of bright sun.

2) If, like us, you store your rig outdoors, even a small solar panel makes an excellent battery maintainer. Combined with a Trik-L-Start, one can basically forget about parasitic loads, for both the coach and the chassis.

I haven't done the math yet, but it is also possible that, over time, one can store up enough power to run heaters to get the batteries through a brief frigid spell. (Not certain about the one). My concern is with an unattended rig while we are elsewhere in the world.

I admit that these are not blockbuster arguments, but they are valid ones. The cost is not huge, but my next van is going to be pretty stealthy, and a panel would detract somewhat from that.

Dunno...

[booster]

Originally Posted by Davydd

I think you are trying to dismiss the advantages of lithium based on your lack of experience with lithium and bringing up the failures of the old Roadtrek eTreks with the parasitics and needing to run you engine in a campground crap.

I’ve had 460 watts of solar and know the little contribution it makes to an 800ah battery pack. I could have driven a few minutes to equal the contribution.

What is the matter with higher electrical loads for cooking such as induction cooktops, Instant Pots, convection ovens and Keurig coffee makers always available? They are kind of nice to have. Maybe if you boondocked with the same electrically advantages of shore power without the husbanding of your batteries you would love it.

Trust me, not having an Onan generator and propane is a blessing. I’d rather have a second alternator than another fossil fuel internal combustion engine. On a short Sprinter I could only get about 100 watts of solar instead of two skylights, a Maxxfan, air conditioner and an automatic Rayzar dome antenna. Underneath, I’m enjoying my 91 gallon capacity in Fresh, grey and black tanks instead of a propane tank and an Onan generator.

AGM batteries (too heavy and too large to obtain equal capacity), propane and Onan generators are old school. Besides it would have been impossible to design a 2500 short Sprinter with the amenities and capacity I achieved with them, which, BTW is the subject of this thread.

I am not dismissing lithium batteries at all as all the comments I made would apply to any type of battery. You have, on your last van, mentioned base use of near 100ah per day and that doesn't matter what batteries it has in it.


My point was, and still is, if you have low parasitic and the other basic use items like cooking, heating, and hot water can be used without adding a lot power use (as in propane appliances or engine fuel ones), then a decent solar bank can significantly add to your boondocking time without driving. That is it, plain and simple. If we are offgrid and have bad sun, we just don't use the microwave as much and use the TV speaker rather than the surround sound and we stay within what the solar panels will give us on average.



Not everyone is a move ever day or two type camper, and we are not. Put us on a nice campsite with some good hiking trails and scenery within walking distance and will gladly sit a week or more until we have to go dump tanks or get water.

[@Michael]

Originally Posted by booster

My point was, and still is, if you have low parasitic and the other basic use items like cooking, heating, and hot water can be used without adding a lot power use (as in propane appliances or engine fuel ones), then a decent solar bank can significantly add to your boondocking time without driving.

True.

With my previous 'all propane' camping trailer my draw on the batteries was so low that my 65 watt solar panel kept my 220AH lead acid batteries charged enough for 9 days of off-grid without external charging, even though I was in partial shade.

The lower your daily usage, the more valuable solar becomes (and the less valuable is lithium).

[GeorgeRa]

Originally Posted by booster

I am not dismissing lithium batteries at all as all the comments I made would apply to any type of battery. You have, on your last van, mentioned base use of near 100ah per day and that doesn't matter what batteries it has in it.
My point was, and still is, if you have low parasitic and the other basic use items like cooking, heating, and hot water can be used without adding a lot power use (as in propane appliances or engine fuel ones), then a decent solar bank can significantly add to your boondocking time without driving. That is it, plain and simple. If we are offgrid and have bad sun, we just don't use the microwave as much and use the TV speaker rather than the surround sound and we stay within what the solar panels will give us on average.
Not everyone is a move ever day or two type camper, and we are not. Put us on a nice campsite with some good hiking trails and scenery within walking distance and will gladly sit a week or more until we have to go dump tanks or get water.

Originally Posted by @Michael

True.
With my previous 'all propane' camping trailer my draw on the batteries was so low that my 65 watt solar panel kept my 220AH lead acid batteries charged enough for 9 days of off-grid without external charging, even though I was in partial shade.
The lower your daily usage, the more valuable solar becomes (and the less valuable is lithium).

I think B class users are split into two primary parties, cruisers and campers, so my way or a highway, or should I say my highway or your way arguments don’t lead to just one ultimate design.

We like camping and we adjust our power usage accordingly, solar panels are critical for us.

I understand why cruisers don’t need PV but I am not a cruiser.

[GeorgeRa]

Originally Posted by Davydd

.........

I’ve had 460 watts of solar and know the little contribution it makes to an 800ah battery pack. I could have driven a few minutes to equal the contribution...................

Did you actually have 460W panels, you had a big hole drilled by ARV in one of them. A big hole can kill a panel.

https://www.classbforum.com/forums/f...tml#post114648

[Bud]

Originally Posted by GeorgeRa

I think B class users are split into two primary parties, cruisers and campers, so my way or a highway, or should I say my highway or your way arguments don’t lead to just one ultimate design.

We like camping and we adjust our power usage accordingly, solar panels are critical for us.

I understand why cruisers don’t need PV but I am not a cruiser.

Might be interesting - the % of each, cruiser vs campers in the B class.

[booster]

Originally Posted by Bud

Might be interesting - the % of each, cruiser vs campers in the B class.

There probably is a poll on that on here somewhere as it comes up a lot.


Based on what we have seen in other discussions, my bet would be the campers will be in the minority.

[MsNomer]

Then there’d the "sometimes we camp, sometimes we cruise" crowd.