Midwest Automotive Designs (MAD) Owners Class B Group

[PotvinSux]

Originally Posted by Rocinante440

Also, in the "Freedom Package" version, the water heater is 100% electric. I believe it's a 5 or 6 gal tank. Given the size of the battery bank, this is probably not a big deal. I worried about this (e.g. using enough electric to heat 5-6 gallons of water) when considering the purchase of a new unit, but now I'm thinking I was probably concerned about nothing.

It 'could' be an issue if AC is running without shore power, however, a cold shower may not be bad on a hot day.

Would love to see an in depth review but these units aren't even listed on their website.

[LA-Hodag2]

Originally Posted by TLooy

Hello!

We just bought a 2018 Weekender and I’m trying to come up to speed on the electrical system on the rig.

It appears that our AGM “house battery” is not holding a charge. In trying to figure out what is going on, I have a couple of questions:
- should the alternator charge the AGM battery while we are driving? (Our battery was fully charged yesterday morning but after we got home from a 4 hour drive and I turned the engine and the Master Power switch off, the Solar Charger Controller showed only 12.4 volts.)
- the Midwest documentation says that the RV is equipped with a “dual battery charging system”. Does that mean solar, generator and shore power will charge both the house battery AND the chassis battery, or does that mean the house battery will charge from two sources?
- when not connected to shore power or running the generator or having the engine running, does the fridge run off of the house or chassis battery? (Note that the fridge continues to run even if everything is off, including the Master Switch.)

One last request (for now): where can I get an electrical diagram that shows me how all the pieces of the electrical system work together?

Thanks!

Tom

Tom, the Midwest documentation leaves much to be desired, as you have seen. The battery voltage on the inverter display is probably more accurate than the one on the solar charger. For some reason, Midwest wired the fridge to run regardless of the position of the master power switch. Go Figure. The only way to shut it off is to use the control inside the fridge (but the light stays active so you can't leave the door open) or pull the 12v fuse, which is what we do when we put it in storage. (In the fuse panel on passenger side rear, below the jump seat. It should be labeled.) Your battery will charge from the engine alternator, when the generator is running, or from shore power through the inverter. It is supposed to charge from the solar panel, but the panel is of pretty low wattage and we have not had much luck getting much juice from the sun. On some 2018s Midwest messed up the solar wiring, and the solar panel charges the chassis battery but not the house battery. Supposedly an easy fix, but I don't know.

Good luck with your new rig!

[TLooy]

Thanks for the details! Very helpful. I have been talking with Sprads RV in Reno NV about a Lithium replacement for the AGMs and also replacing the inverter and solar charger at the same time. I’ll post here the results if we go that route.

[PotvinSux]

Anyone see a Midwest Patriot yet on the transit chasis? I believe it's going to be the only transit rig without propane.

[LA-Hodag2]

Hi All. Reporting back on the lithium battery conversion and 12v air conditioner install in our 2018 Midwest Automotive Weekender MD-2. In short, the result is everything we were hoping for. At 90+ degrees ambient with the black van parked in direct sun and no windows shaded, we have been able to run the a/c off the batteries for over 7 hours. Our intended use is less taxing. We will never sit in the van in the hot sun all day. We do regularly overnight on city streets or parking lots and want a/c at night and enough battery to run the fridge and make coffee in the morning. Since we will not be in direct sun and will likely have lower ambient temps, the compressor will not run constantly as it did during my daytime test, when it drew around 70 amps. We expect decent battery reserve in the morning and respectable level of recharge by a couple hours driving (or running the generator if necessary). We haven’t been able to fully test it just yet.

Our van came from Midwest with two size 8-D Lifeline AGM batteries installed in custom boxes under the van where the spare tire would be stowed. We had a typical 13,500 Dometic roof air, the Xantrex 2000 watt inverter, and an Onan 2.5kw propane generator. The air conditioner could only be run on shore or generator power. We also have 200 watts of solar and a large Nova Cool compressor fridge.

We replaced the batteries with Chins brand 300AH lithium batteries with integral heaters, for a total of 600AH capacity. The batteries are almost exactly the same dimensions as the Lifeline 8-Ds they replaced, so they fit perfectly in the existing boxes. Of course they are much lighter. We were able to use much of the wiring from the original batteries as well. We did not change the inverter, which is theoretically capable to charge at 80 amps, but seems in actual usage to top out at about 65 amps.

We could have kept the Dometic rooftop air conditioner and run it by replacing the inverter with a 3000 watt unit and adding a soft start, but the cost of doing that was about 2/3 the cost of replacing the a/c unit, and we would have had significant loss of useful battery life due to inverter inefficiency losses. We replaced the air conditioner with a unit called Electra-Kool by ProAir. The 12v unit puts out 20,000 BTU, more than 30% more cooling than the Dometic. The ProAir fit the existing cut-out in the van’s roof, but the unit’s exterior dimensions are different than the Dometic and we had to relocate a solar panel so it would fit.

To charge from the engine, we installed two Victron Orion 30amp battery to battery chargers, so the engine alternator can recharge at up to 60 amps. To monitor the system we added Victron BMV-712 smart battery monitor. The chargers and the monitor are all Bluetooth enabled, which makes them easy to use and really helps monitor power usage and state of charge. Other than a lot of cables and a number of circuit breakers, the only other significant component was Victron Lynx distributor, which is basically a box that combines positive and negative buss bars with space for mega fuses (150amp for the air conditioner) for each circuit.

The only real installation glitch we encountered resulted from following ProAir’s instructions to use 4 gauge wire from the distribution panel to the air conditioner. The unit would shut down due to low voltage at high load. We re-ran the connection with 2AWG wire and it works fine now.

The air conditioner is much quieter inside than the Dometic was. Much quieter. However, it is louder outside. Outside it makes a high pitched buzz, like a very large swarm of bees. It’s not terribly intrusive, but is certainly noticeable from 100 feet or less. The interior air handler is sleek and, to my eye, much more attractive than the Dometic. The controls are built into the bottom of the air handler unit. A remote thermostat is available, but we didn’t bother.

The components were pricey, but we are really happy with the end result. This setup is certainly not for everyone, but some may find our experience helpful. In addition to our urban and wilderness boondocking use, I think this type of setup will work well for those who want to keep their pets cool in the van while they are away for a few hours, or for those who want to cool the rear of the van while underway without running the generator. This setup could work with a smaller battery bank, such as a single 300ah or several 100s.

The Midwest vans have really high-end interiors and better storage than others we considered, so we were already really pleased with our rig. Having battery powered a/c really completes the package for us.

Here are details of the major components we used:

2x Chins 300AH smart lithium phosphate batteries. $1,400 each on Amazon, shipping included. (Arrived about ten days after order.)

ProAir Electra-Kool roof air conditioning unit. $2500 plus shipping. (For some reason, this unit does not appear on their website, but just call them. They have white and black, 12v or 24v)

2x Victron Energy Orion TR Smart 12/12-volt DC to DC charger, isolated. $273 each, on Amazon.

Victron Lynx 1000 distributor. About $300 from a Victron dealer online.

Victron BMV-712 battery monitor. About $200.

I hope somebody finds this useful.

[TLooy]

Thanks for the detailed write-up! Very informative as I am in the process of upgrading my 2 AGM batteries to 4 BattleBorns. I'm especially interested in why you went with 2 DC-DC converters rather than a BIM.

[LA-Hodag2]

Originally Posted by TLooy

I'm especially interested in why you went with 2 DC-DC converters rather than a BIM.

Hi TLooy. I won't pretend to know how the battery to battery chargers work, but I was told by several electrical engineers that they would be more effective at recharging my batteries and better for my alternator than a simple battery isolation manager. One comment I recall is that since a BIM protects the alternator from overheating by essentially shutting off and turning on charging in cycles of 15 or 20 minutes, it will take twice as long to charge the batteries because charging is off for about half the time, whereas the B to B is constantly charging. That makes sense to me, even if I don't understand how the B to B works. Also, you can wire two or more B to B chargers in parallel to increase the amperage pumped into the batteries. LiPo batteries can take high amperage from the charger. Additionally, the chargers are controllable and can be monitored by bluetooth. Finally, they automatically isolate the house batteries from the chassis whenever the engine is off. I don't know if a BIM does that.

A BIM may work just as well, especially for a smaller capacity battery bank. This is just why I made the choice I made. So far, it has worked well. Good luck with your project. I hope you will post here with the results.

Bryan

[TLooy]

Hi Bryan. Thanks for the response. I'm learning a lot about these systems too so thinking through this with you is really helpful.

From what I understand the BIM will isolate the house batteries from the chassis battery when the engine is off thus protecting the chassis battery from being discharged when not driving.

I believe that when the BIM is engaged the lithium batteries are drawing from the alternator at near 100% of the capacity of the alternator for 15 minutes and then it's off for 20 minutes to cool off the alternator. Running your 2 DC-DC chargers will draw probably less than 50% of the alternators capacity but for a prolonged period of time, likely hours if you have discharged your batteries a lot.

So to dumb it down for me the question is: do I want the alternator to produce approximately 40% of its capacity 100% of the time until my batteries are charged (DC-DC option) or approximately 100% capacity 40% of the time until my batteries are charged (BIM option). At the moment I'm leaning towards to the 2 DC-DC charger option.

(Note: on the Battleborn website their system configurations call for a BIM when you have more than 2 100Ah batteries and a DC-DC converter when you have 1-2 batteries. They say that having 1-2 100Ah batteries will draw too much amperage into each battery during charging and potentially damage them. Have more than 2 balances the amperage across more batteries and therefore less amperage going into each battery.)

Tom

[LA-Hodag2]

Hi Tom. As I said, I'm not advocating for any particular setup, just telling what I did and why. There are lots of people on this site who understand the electrical engineering much better than I do and there are many other ways to configure a system, so you should look for advice from them.

Bryan

[TommyHarris]

We are excited to be taking delivery of a 2022 American Coach Ford Patriot next month. Total electric - no LP, so we'll see how it goes! See you on the road! :-)

[LA-Hodag2]

Originally Posted by TommyHarris

We are excited to be taking delivery of a 2022 American Coach Ford Patriot next month. Total electric - no LP, so we'll see how it goes! See you on the road! :-)

Nice! Looking forward to hearing about it. Does your model have a generator, or rely on charging from the van engine?

[Rocinante440]

If we could get a MAD van in a Ford Transit 2500 extended chassis with EcoBoost and AWD, that would be wonderful. Someday, maybe Ford's constrained availability will be resolved and that will become possible.

[TommyHarris]

No generator - charged from solar, engine alternator or shore power.

[rvtraveler10]

Originally Posted by TommyHarris

No generator - charged from solar, engine alternator or shore power.

Please keep us updated. I am looking at the same one, MD2.