Coachmen: 12V power upgrades to our 2016 300DS

[LSVLance]

After a 5 am wakeup call from a low voltage warning from our Carbon Monoxide monitor while boondocking, we decided that would never happen again and started to put a plan in place to remedy the situation. I spent a lot of time researching and found some very helpful blogs on the subject. The 12volt Side of Life The 12volt Side of Life (Part 1) probably helped the most along with some vendors and Aaron (wahoonc).

Here is a list of the parts we bought before starting the upgrade.

Products Ordered:

Trimetric 2030RV Battery System Monitor
Shunt: 500 Amp, Cable: 35 Ft. Meter to Shunt Cable

PST-2000-12 Samlex PST-2000-12 Pure Sine Inverter

ZS-200-P Zamp 200 Watt Portable Solar Charging System – ZS-200-P
Accessories: Add Plug and Cord

PD4655V PD4655V 55 Amp Converter Upgrade Section

PMTS-30 Powermax 30 Amp Transfer Switch (2)

EMS-PT30C EMS-PT30C 30 Amp Portable EMS

Duracell GC2 XHD 6 Volt Deep Cell Batteries (2)



I have never really done much work on RV systems before but am pretty mechanical in nature and have friends to lean on for consultation if needed...so away I went.

My plan was to start out the outlets I wanted to power from the inverter and work my way backwards all the way to the inverter. Our 300 DS has 11 outlets, 6 on the GFI circuit and 5 on the Bedroom\Overhead entertainment circuit. The fridge was also on the BR circuit and I did not want it to be powered by the inverter. So the plan was to isolate out the fridge outlet, leave it on the coach circuit panel and then run the rest of these two circuits to behind the fireplace where the inverter would live.

This actually turned out to be way easier than I thought once we dug in. I'll update how we did this in my next post, right now dinner is calling.

[LSVLance]

First we followed the Fridge/Bedroom circuit from the control panel, it led to the outlet in the compartment behind the fridge where the fridge plugs in. One wire in, two wires out. We separated the somewhat skeptical outlet, installed a weather proof box and outlet and connected just the wire from the panel to the outlet. This is now a circuit just for the fridge.

The other two wires had enough slack in them to pull back down below the shower to just behind the control panel. They led to the bedroom outlets and the overhead entertainment outlets.

The other circuit that fed the GFI circuits was removed from the panel and rerouted to that junction box as well.

We put a 30 amp breaker in the bottom of the panel in the last open spot and ran 10 awg wire to up behind the fireplace where the inverter would go and ran two 12 awg wires back to the junction box.

The idea was the 30 amp circuit would feed a transfer switch the inverter would also feed, this switch leads to a sub panel with 2 15 amp breakers in it which feed the GFI and Bedroom circuits.

Here is the 3 wires we ran from the control panel to transfer switch.



The junction box behind the control panel



The auto transfer switch on right, sub panel on left.



And here is the control panel pulled away from wall so we could add and remove wires from it.



This was where we ran into the first hassle. The plastic clips the manufacturer used to clamp the wires to the back of the panel housing are like a zip tie...meant for single use only. We were finally able to pull the push pin out, loosen the wires and reuse the clips again. An alternative might have been to remove them and replace them with real clamps but this would have meant taking each wire loose and wasn't our first choice.

Since we were going to be making so many changes to the electrical system, we decided to make a change and then test everything before moving on to the next part. With the two outlet circuits completely re-ran thru new main panel breaker, transfer switch and sub panels breakers back to the junction box and outlets, we plugged the shore power back in and tested...all 11 outlets were good.

[LSVLance]

Next up was installing the inverter. I kind of went overboard with the 2000 watt inverter, but I only wanted to do this once and our main goal was to be able to make a cup of coffee or two in the morning while watching the morning news on TV without having to start the Genset and the Kuerig uses about 1350 watts. What I learned during the install is stepping up from the 1500 watt to the 2000 watt inverter also means MUCH larger wire to feed the inverter as well as larger connectors, fuses, and shunt for the battery monitor. Overall I'm glad I went this route and also glad I chose to over wire vs underwire so that everything is plenty safe to run even at full draw.

The inverter puts out about 16 amps, so 12 awg was used to hard wire the inverter to the auto transfer switch. Requirements for the battery leads are 2 / 0 awg. I found it in multi strand bulk at OReillys and bought 2 six foot pieces. I also bought a handful of 3/8s stud 2/0 connectors, some 3/4" shrink wrap and borrowed a real nice crimper and cutter from a friend.



The inverter needs an inline 300 amp MRBF less than 7" from the battery and a direct line from there to the DC input. I found the fuse and a fuse holder at OReillys as well. I ran the 2/0 ground wire from the inverter to the chassis ground under the battery box and then ran another 2/0 wire up to the battery box where I connected it to one side of the shunt. The other side of the shunt went to the negative battery post. I'll explain what the shunt does later.

Here is the inverter mounted on the wall behind the fireplace.



This is what the mess of wires beside the battery box looked like when I started.



I spent some time testing and tracing to figure out what each wire in there does so I could rearrange them to clean up and make room. Here is what it looks like now with the original connections moved to the left, new holes drilled for the new 2/0 wires and Marine Ready Buss Fuse and Shunt mounted and wired up.



I decided to upgrade the 24DC 12v batteries to GC2 XHD 6 volt batteries. These batteries were about 1.5" taller but fit very well into the OEM box. I did have to redo the battery cables though as they had to be wired in series instead of in parallel. Here are the new batteries in place and wired up.



The last connection I make was the battery positive cable to the 300 amp fuse. You have to watch out as the inverter has capacitors in it and the first time power is put to the inverter a LARGE amount of juice flows. It made a spark like a welding arc when I touched the cable end to the post. Be careful for this step.

Once all connections were doubled checked for tightness we tested everything again to make sure it all worked as planned. I had the control panel feeding the transfer switch and the inverter turned on. When I flipped the 30 amp breaker off feeding the outlet sub panel, the transfer switch clicked...then in about 15-20 seconds the outlets became live again only this time the batteries were feeding 120v to the outlets through the inverter!! SWEET!!!

[LSVLance]

The next upgrade was to add another 30 amp auto transfer switch back where the shore power line connects to the coach. OEM setup was a plug outlet for the Genset feed that the shore power line had to be plugged into for the Genset to feed the control panel.

We took that outlet off and found the Genset feed and line to control panel leading to a blind space between the cord cubby and the rear storage compartment held in place by another of those stupid single use plastic clips. This clip suffered catastrophic failure during removal.





In the storage compartment we removed the light and the box covering the slide controller and figured out we could pull the Genset and control panel lines to this side with fish tape where we put them in a junction box and extended them to where the new transfer switch would mount.





We also drilled a new smaller hole in the cubby hole side, put a grommet in and fed the shore power cord to the storage compartment as well.



We then mounted the transfer switch, wired the Genset, control panel and shore power lines to the transfer switch and buttoned everything back up again then tested.







The first benefit of this switch is not having to get out to plug the shore power cord into the outlet if you need to run the Genset, the second is not having that large box in the way when trying to stuff the cord back into the cubby hole. The transfer switch works seamlessly and was well worth the trouble it took to fish those stiff 10 awg wires through the blind space.

[LSVLance]

That last interior electrical upgrade was the Progressive Dynamics DC converter with the 3 stage battery charger we put in place where the WFCO 8955 converter was in the lower portion of the control panel. This upgrade was made in an attempt to take better care of the RV's batteries with faster charging when batteries are low and slower topping off of batteries when nearly full.

We thought this would be one of the easier jobs but in reality it turned into one of the more frustrating mainly because of the plastic clips holding the 12v battery feed wires to the back of the DC side of the panel box. That and the places the 2 gauge battery wires hook to the new DC panel were different and the wires did NOT want to bend into place. This swap took two of us several hours and many cuss words while trying to get short stiff wires to play nice. Not sure how I would do it differently if I had to do it again, just know going in you might have a fight on your hands if you decide to make this upgrade.

Having a 3 stage battery charger now hopefully makes up for the hassle, we'll see as we go along. Sorry I don't have any pictures taken during this part as we just didn't stop to take any.

This catches my project up to date. I'm still working on installing the Battery monitor and remote for the inverter, once I get those in I'll share pics and then put the rest of the interior of the RV back together again. I'm also waiting for the solar panel suitcase kit to arrive so I can figure out how to wire the cable to charge the batteries with the free sunlight.

All of these upgrades were designed to make the Class B+ electrical system work as seamlessly whether plugged in or not as most larger Class A RVs do. I think it's turned out well and I hope by sharing this more of you that have similar wants might be tempted to make the upgrades as well. I'm happy to share and help out anyway I can as I know it's easier to do a project like this if you have someone to kind of show you the ropes. I know I've leaned on a few people during the install to get me past the questions I had.