This is a quick and dirty post of our solar install. We didn't find a lot of info in one place, but what we found in this forum was a huge help.
After deciphering how the battery boost, coach battery relay, and wiring for how all this interacted, what we found was easy to work with once we had a plan.
We ran a new 4 gauge red battery (welding) wire from the 4 pole Positive to the input side of the battery disconnect relay (located under the passenger seat). See Photo. We chose 4 gauge as that's what was used both by Mercedes and Winnebago.
Next, we disconnected wire KE from the Battery Boost toggle switch. We connected wire KE (this wire becomes energized when the engine turns on) to the Ignition input on the DC-DC MPPT Charge Controller. We also ran a 4 gauge wire from the starter battery back to the DC-DC MPPT Charge Controller as this allows the alternator/starting battery to charge the coach batteries as we drive.
Using a hydraulic rolling car jack and some blocks of wood, the battery boxes were removed from the coach and the AGM batteries were removed.
To fit the 4 Renogy 100ah lithium batteries, we used the 2 existing AGM battery boxes with a few modifications so the batteries would fit.
Each box consisted of:
1) the bottom plate being inverted, and 2 screws were added in the back to keep it level.
2) a 16 gauge plate (13" x 12"), of which a 1/2 inch of the plate was bent to 90* to keep the batteries in place. The plate was tack welded onto the bottom plate.
3) brackets were added to keep the batteries firmly mounted and in place.
Each box is now about 2 lbs lighter with the new batteries and modifications, than when the box held the AGM battery.
The small modification allowed the Renogy batteries to be placed side by side in the existing battery box. Using the hydraulic jack, we raised the boxes back up to the undercarriage of the van and reattached. When remounting the battery boxes, the drivers side had an obstruction so we had to extend the bolts about 1 1/2 inches. The obstruction was the 2 winterization drains (I added some cheap hose to extend the drain) down past the battery.
I would have gotten pics of all this but it was raining on and off so I was in a bit of a hurry - I'll get pics if someone asks.
The rest of the coach wiring was per the attached (but hard to follow) schematic. We ran the Solar Panel wiring down the chase that's in the closet and the solar disconnect is where the OEM inverter was located. From there the wires go over to the DC-DC MPPT Charge Controller. All the other components are in the same space as the water heater and furnace (that side).
As I mentioned, I will attach more photos when I can.
Thanks to all who helped me chase down wires and figure out how to best do the install!
After deciphering how the battery boost, coach battery relay, and wiring for how all this interacted, what we found was easy to work with once we had a plan.
We ran a new 4 gauge red battery (welding) wire from the 4 pole Positive to the input side of the battery disconnect relay (located under the passenger seat). See Photo. We chose 4 gauge as that's what was used both by Mercedes and Winnebago.
Next, we disconnected wire KE from the Battery Boost toggle switch. We connected wire KE (this wire becomes energized when the engine turns on) to the Ignition input on the DC-DC MPPT Charge Controller. We also ran a 4 gauge wire from the starter battery back to the DC-DC MPPT Charge Controller as this allows the alternator/starting battery to charge the coach batteries as we drive.
Using a hydraulic rolling car jack and some blocks of wood, the battery boxes were removed from the coach and the AGM batteries were removed.
To fit the 4 Renogy 100ah lithium batteries, we used the 2 existing AGM battery boxes with a few modifications so the batteries would fit.
Each box consisted of:
1) the bottom plate being inverted, and 2 screws were added in the back to keep it level.
2) a 16 gauge plate (13" x 12"), of which a 1/2 inch of the plate was bent to 90* to keep the batteries in place. The plate was tack welded onto the bottom plate.
3) brackets were added to keep the batteries firmly mounted and in place.
Each box is now about 2 lbs lighter with the new batteries and modifications, than when the box held the AGM battery.
The small modification allowed the Renogy batteries to be placed side by side in the existing battery box. Using the hydraulic jack, we raised the boxes back up to the undercarriage of the van and reattached. When remounting the battery boxes, the drivers side had an obstruction so we had to extend the bolts about 1 1/2 inches. The obstruction was the 2 winterization drains (I added some cheap hose to extend the drain) down past the battery.
I would have gotten pics of all this but it was raining on and off so I was in a bit of a hurry - I'll get pics if someone asks.
The rest of the coach wiring was per the attached (but hard to follow) schematic. We ran the Solar Panel wiring down the chase that's in the closet and the solar disconnect is where the OEM inverter was located. From there the wires go over to the DC-DC MPPT Charge Controller. All the other components are in the same space as the water heater and furnace (that side).
As I mentioned, I will attach more photos when I can.
Thanks to all who helped me chase down wires and figure out how to best do the install!
Attachments
Last edited:
