Renogy DC50S vs MPP All-in-One...Does any system do Solar/DC-to-DC/Shore Conversion/Inverter all in one box?

[Lblamboy]

Hi. I am new and about to convert a Ford Transit for my daughter to use when going to horse shows. We're hoping to install a shower (with a Hot Water Heater) and a compressor-driven Air Conditioner unit for the roof, both of which will be major energy drags over and above the usual Fridge and fan and lights and stuff in a conversion van.

I've been reading and trying to get smart...but am looking for a product that might not exist.

I LOVE the idea of the Renogy DC50S system, as it would allow me to use the Ford 150A Alternator to charge house batteries pretty easily. It seems some people also prefer the KISAE DMT1250 to do a similar job. What I like about those systems is the ability to have solar and/or the Ford Alternator recharging the House batteries. What I don't like is that I'd apparently have to wire up a separate system for incoming Shore Power, including a battery charger and inverter or a combo of some sort

I also LOVE the MPP All-in-One systems that Will has on his site and in some videos...those seem plug and play for a solar input and shore power inputs, but the downside is that it doesn't seem to have the DC-to-DC features that the Renogy has that would let me tap into the Ford Alternator.

Given that the ideal design calls for a ton more power than I probably have space to generate on the roof of the Transit (It's a Med Roof, Long Wheel Base, but still not THAT big), I'm assuming we will need to top up the house batteries with shore power sometimes/pretty regularly...but she wants to be off-grid as much as possible...and so I'm trying to design something that will let her utilize Solar, the Alternator, AND let me do Shore Power when needed....but being new, I'd also really prefer something that puts it all in one box without breaking the bank.

Thoughts for the newbie on how to deal with the power equipment challenge? Does the animal I'm seeking exist at any reasonable price point?

 

[ianganderton]

Have you worked out how many watts you are going to need? With water heating AND aircon you will be pushing the very limits of what’s possible in a vehicle based system

the 2 devices you’ve mentioned won’t even come close

The size system I think you are going to need will likely make the alternator charging virtually worthless

have you done a power audit yet? How many watts a day do you expect to consume?

 

[ianganderton]

And how many watts of panels can you get on your roof?

Do you have a water heater in mind? If so what are the specs? Voltage, peak amps and predicted watts needed perday

for the water heating you will probably be better off looking at gas or other forms of energy. Solar is not very good for that

where about are you?

 

[Lblamboy]

We're considering a Hot Water Tank that uses engine coolant heat exchange, which might lower the energy needs for the water...but that gets painful in other ways.

We're considering an evaporative cooling unit that would dramatically reduce the A/C power needs, but that system won't work well in higher humidity areas, so it's not ideal either.

Net, net...I'm wondering how people with compressor-based A/C units get by with anything other than a hookup every day...and I'm trying to build a system that would let her be off-grid when the A/C isn't as critical, but on-grid when her mother comes and/or when it's too humid for normal cooling systems to do the trick....but yeah...It's an obnoxiously tall order to think I'm gonna make this easy from the energy demand side.

Either way, I'm kinda hoping a true "all in one" box exists and wanted to get ideas about that...because it would mean she could do hookups some, and be off-grid when A/C isn't as needed.

 

[Lblamboy]

Even if we stayed with an electric hot water tank (she doesn't want to fool with Propane), I'm seeing estimates of 45 amps to fill a bottle...not great, but workable numbers...

I'm also seeing like 5 Amps type numbers for the draw on a large evaporative cooler, which is also reasonably workable, so it's really just the compressor-driven A/C that would break all the math...and so I'm trying to decide whether it's best to gamble with an evaporative cooler that might now always be sufficient, or do a "real" A/C unit and then build the electric infrastructure to be multi-faceted enough to accommodate being off and on-grid at different points as needed...but that means have a LOT of components potentially...and that makes for more failure points for me as a new installer...so I really like the idea of finding one box that helps do it all...even if that means really having to squeeze out every inch of roof space for solar and/or connecting to shore power somewhat regularly.

 

[ianganderton]

I dont think you'll get an all in one box that will include the altenator charging but its a very simple add on.

One thing to check when looking at the all in ones (and any powerful system) is fan noise. Some seem to be noisier than others and that will make a difference in a confined space (not so much in residential solar sheds)

Probably the most integrated option will be something from victron. Have a look here https://www.victronenergy.com/inverters-chargers

 

[ianganderton]

Even if we stayed with an electric hot water tank (she doesn't want to fool with Propane), I'm seeing estimates of 45 amps to fill a bottle...not great, but workable numbers...

I'm also seeing like 5 Amps type numbers for the draw on a large evaporative cooler, which is also reasonably workable, so it's really just the compressor-driven A/C that would break all the math...and so I'm trying to decide whether it's best to gamble with an evaporative cooler that might now always be sufficient, or do a "real" A/C unit and then build the electric infrastructure to be multi-faceted enough to accommodate being off and on-grid at different points as needed...but that means have a LOT of components potentially...and that makes for more failure points for me as a new installer...so I really like the idea of finding one box that helps do it all...even if that means really having to squeeze out every inch of roof space for solar and/or connecting to shore power somewhat regularly.

Its worth talking in watts or quoting both the voltage and the amps. 45amps at 12v is very different from 45amps at 48v

 

[Lblamboy]

I was assuming a 12V convention for appliances was pretty standard...I haven't run into many 24V or 48V applications yet...but point well taken.

The total energy demand nothwithstanding, my core question right now, though, is just how to build the setup to cover all bases...I imagine shore power will be somewhat common when we start (getting used to van life and slow to give up certain comforts) but then rarer long term...and I imagine that it would be fair to assume that I wouldn't need both shore and Dc-to-DC at the same time ever...so maybe I roll with both a Renogy (or Disae) unit above for off-grid needs and a second separate shore power setup of some sort...it's less satisfying, and I'd have to consider whether I get a separate inverter that could be downstream of them both, and how to wire it so as to correctly isolate the house batteries and inverter from whichever system was "off" at that point?! That's precisely the kind of thing I was sorta hoping to avoid though...I can't imagine I'm the only person who is trying to build a system that is both on and off-grid ready and who still wants dc-to-dc...and who will want an inverter in either scenario active, but doesn't want to make a mistake and learn the hard way...or spend an inordinate amount of time setting up isolation switches/relays or maybe even duplicating some components if I'm not careful.

Re Victron - Prices seem stratospheric, and they don't do a very good job speaking in terms a newbie will understand...the site comes across like "You know who we are, and you know what this stuff does...and if you don't, you probably couldn't afford it anyway" LOL

 

[ianganderton]

Folks here will give you a hand but you need to go through a process. Go one step at a time and you will understand the decisions as you go

first port of call is understanding what you want to power

you need to make a list of everything you want or might want to run. Then you need to look at the voltage it runs on and how many amps it draws or watts uses. Then you need to estimate how long you are likely to run it

this is known as a power audit. It’s a tedious pain in the ass but if try and side step it you will either waste money or not be able to power what you want.

without a power audit folks here who know what they are doing can’t really help you

search for power audit in the resources section. There is a spreadsheet there

 

[Lblamboy]

Ian, I understand the value of the power audit...but I'm kinda "between" different options on the most power-hungry design choices right now...if I go "lite" I won't have power production issues at all, but it might not work in all settings for cooling, plus I know my wife will occasionally want to do hookups when she comes anyway...and if I go "heavy" I know that I can't ever have enough solar and alternator help to be fully off-grid and operate day after day without draining the house...so, long story short, I KNOW that I need infrastructure for both off and on-grid options...that we will likely end up doing both at times...and the audit doesn't change the fact that I'd ideally want a true all-in-one box that can do Shore/Dc-to-DC/Inversion/solar...it would mostly just affect "which" such box I need re sizing...

For now, though, I'm just trying to decide if such a unicorn box even exists...the answer to that question helps push the decision on actual components a bit, not the other way around in my case.

 

[madmax]

the unicorn does exist. you just may not like it. Run a dc air conditioner. not the standard rv style. you want 18 wheeler trucker cab style. they have ones designed for dc operations. Run a gas powered water heater. if you ever want to run heat, get the combo unit. very little gas and electrical use for what they do. if you burn more than a gallon a week for hot water, you must have a very very large water supply.
So far every item has been dc. you technically do not need an inverter. keeping everything dc is significantly more efficient, as your power source is also dc. while they do make dc water heaters, resistive element heating is efficient (in the electrical sense) but not the best use of resources.

as far as charging the battery bank, either a dc to dc on board charger, or a 120v to dc.
the mpp unit I have i believe will still charge even if the inverter is off. , so you can still charge your batteries via solar or shore power, without the inverter overhead. it still leaves you the option for 120v items should you need it.

 

[ianganderton]

There are lots of solar charger/ AC Charger/ inverter all in one options but I doubt any with dc to dc charger especially at the size you will need for Ac and water heating

but

adding a seperate dc to dc charger device is probably one of the easiest to add to a system so there is no point hanging your decision on just that. Doesn’t make sense

 

[Lblamboy]

Ian, it seems like many of the combo units essentially become much more affordable than buying the components separately...so I was hoping the same would be true if a unit also had the DC-DC part too...but if that animal doesn't exist, then I have to sorta decide if I want to build a system that has a second Solar Charging unit, or just buy a straight DC-DC charger...and even thinking about that makes my head hurt a little...In 99% of the use cases I would have, I would either be on shore power a fair bit...or not at all...hopefully not at all most of the time...and that makes me wonder if it's better to wire something that just keeps the on-grid and off-grid systems isolated to some degree....or if that's even possible without losing the on-grid system's invertor function. Net, net...it sounds like just adding the DC-DC charger would probably be simple and that I'm likely overthinking it since I haven't done this before...

BUT...let's say I have a separate Bat-Bat charger....is there any way to run that while the "Shore power" combo (inverter/charger and MPTT) is active, or would that freak out the "Shore Power" box if it sensed a second charging source pouring into that battery?! Basically, if I don't have an MPTT on the DC-DC, or an inverter....am I basically settling for Alternator-only charging of the house, or could both systems operate at the same time (assuming they are wired correctly?)

 

[Lblamboy]

the unicorn does exist. you just may not like it. Run a dc air conditioner. not the standard rv style. you want 18 wheeler trucker cab style. they have ones designed for dc operations. Run a gas powered water heater. if you ever want to run heat, get the combo unit. very little gas and electrical use for what they do. if you burn more than a gallon a week for hot water, you must have a very very large water supply.
So far every item has been dc. you technically do not need an inverter. keeping everything dc is significantly more efficient, as your power source is also dc. while they do make dc water heaters, resistive element heating is efficient (in the electrical sense) but not the best use of resources.

as far as charging the battery bank, either a dc to dc on board charger, or a 120v to dc.
the mpp unit I have i believe will still charge even if the inverter is off. , so you can still charge your batteries via solar or shore power, without the inverter overhead. it still leaves you the option for 120v items should you need it.

I had just started looking at DC Air Conditioning trucker type systems...Webago makes a few...and ThermoKool has some serious options too...Do you know of any affordable "Trucker-grade" solutions for A/C?

and yeah, I'm starting to get more comfortable with the idea that the water heater needs to be non-electric too...

 

[Lblamboy]

Oh, and FWIW, I had assumed I will need the invertor aspect in an integrated box....because I'm probably "cheaping out" on the fridge and getting a college dorm fridge for budget reasons...but if the fridge is connected to the integrated box invertor and needs to stay on full-time...that begs the question whether I need "just" a new DC-DC charger, or if I need to have that component with an MPPT, with some isolation to the other box?

 

[madmax]

I had just started looking at DC Air Conditioning trucker type systems...Webago makes a few...and ThermoKool has some serious options too...Do you know of any affordable "Trucker-grade" solutions for A/C?

and yeah, I'm starting to get more comfortable with the idea that the water heater needs to be non-electric too...

they are generally more expensive, which is why most rvs use ac instead of dc. also remember that up until recently lithium cells weren't really affordable or avaliable for rv systems. your "house" batteries were all deep cycle batteries. air conditioning and microwave often times were relegated to generator operation.
I know of some cheaper but not necessarily more reliable. they run something similar but use plumbed cold air through like. 40mm pipe., the rest of the unit sits in unconditioned space. You would need to at least cut a louver in the side of the van to vent the heat.
depending on your hot water needs, you can also use your engine for the heat source.
they sell flat plate heat exchangers, usually for less than 100 bucks. If you plumb it into your coolant system (heater side) it will heat it up pretty quick. I had one in my off road rig, and it was actually too hot for me. I dont know if you plan on carrying water or not. Water is heavy. and showers use quite a bit of water. if its summer time you can fill a water bladder and leave on the roof and cover with a black tarp/ garbage bag. water will be scalding hot in less than a few hours. you'll also keep your van cooler in the day.
I've tried all sorts of hot shower systems, and they were all too complicated. The heat plate one worked well, but was difficult to control temperature without blending valves and another pressurized source.
I also had one of those propane heater setups using 1 lb canisters... another pain to setup and take down.

ultimately the 5 gallon bucket, and a 12v shower head proved to be the most cost effective, space saving and comfortable. Just heat up a pot of water, and add cold water to mix to your desired temp. make two buckets if you like. in the warmer sunny months, I just kept the buckets in the truck. Still warm after dark. you can also place outside for solar heat. The shower head is the best part. they plug into the cigarette lighter, and they have a motor pump that drops into the bucket. The on/off is located on the shower head. You spray up, turn it off, lather up, and then spray down. Once your done, its easy to put away, right back in the same bucket. Its always clean in the bucket because no grey water ever goes in. I usually packed it with my towel, hair/shower gel, and other toiletries. If you need more hot water, just nestle an extra few buckets.
Most shower heads are between 1.5-2.5gpm, so if you stop between lathering and rinsing you get a very decent clean shower.
Its also useful for spraying off your muddy horse poop boots. Not my favorite smell, but beats a lot of others.

 

[madmax]

Oh, and FWIW, I had assumed I will need the invertor aspect in an integrated box....because I'm probably "cheaping out" on the fridge and getting a college dorm fridge for budget reasons...but if the fridge is connected to the integrated box invertor and needs to stay on full-time...that begs the question whether I need "just" a new DC-DC charger, or if I need to have that component with an MPPT, with some isolation to the other box?

highly do not recommend dorm fridges for vehicle use. they are often simple evap units and Re not isolated or shock absorbing for actual travel use. You do have to weigh your overall situation. 500 will get you an edgestar fridge freezer. if your sole reason for needing an inverter is for the fridge, I'd skip it .