Has anyone done this (factory solar mods Momentum 21G)

[NickinCO]

In researching the system I want I’m contemplating redoing some of the factory solar. My idea is to leave the cheapie golf cart batter on the frame behind the propane tanks but change it’s connection to strictly power the generator start up and power Jack. I would disconnect the 300w panel and add a 100w panel to keep this battery charged along with the 7pin.

The existing 300w panel would be ran in parallel with another identical panel and a new hole tapped in the roof to shorten the wires directly over the exterior storage behind the closet. These panels would be ran off a new Victron controller and attached to 400 to 570aH of lithium batteries also in this compartment.

thoughts?

[acoleman43]

NickinCO That's an interesting idea. I've never thought about it.

'm no expert but it seems you are making it more complicated by trying to isolate the front jack and generator to one power source, everything else to a separate source. Seems much easier to just power everything from the lithium batteries.

also, the 300W Jaboni panel is $750. Yikes! Unless you're much more wealthy than I (which is entirely possible) That's a chunk of cash for just 300W.

Also, directly over the master closet is the front cap.

[NickinCO]

NickinCO That's an interesting idea. I've never thought about it.

'm no expert but it seems you are making it more complicated by trying to isolate the front jack and generator to one power source, everything else to a separate source. Seems much easier to just power everything from the lithium batteries.

also, the 300W Jaboni panel is $750. Yikes! Unless you're much more wealthy than I (which is entirely possible) That's a chunk of cash for just 300W.

Also, directly over the master closet is the front cap.

hah! I thought I was making it less complicated. Less rewiring to do, less to hook up to house batteries, and if I’m adding solar I will likely have to run some larger cable than 10awg as well. They don’t appear to have went out of their way to make the cable runs as short as possible. That’s a bummer about what’s directly above that exterior storage, I guess I wasn’t paying close enough attention.

as for panels are you aware of any 300w panels with a matching voltage that I could pair up with the existing jamboni?

[howson]

NickinCO -- figuring out what to match up with your Jaboni panel (other than another Jaboni) will take some homework.

If you're interested in how I resolved the panel purchase question, I documented the process (at length!) here: https://gdrvowners.com/forum/solar/1...n-2019-315rlts

Howard

[NickinCO]

NickinCO -- figuring out what to match up with your Jaboni panel (other than another Jaboni) will take some homework.

If you're interested in how I resolved the panel purchase question, I documented the process (at length!) here: https://gdrvowners.com/forum/solar/1...n-2019-315rlts

Howard

Great write up! I used the same panels in my van. I’m not sure what the used market for a 300w Jamboni panel is but I can’t imagine it fetching anywhere close to what they cost retail. Since I already have one it seems to make the most sense to purchase another even for $750 since that’s what it would cost to replace with the same total wattage of renogy eclipse’s. It would depend what my total solar requirements are which for right now I believe to be 600 to 900w. Between that, a 400-540aH battery bank, and the cumins generator, I think anything more would be grossly overkill. Our van setup had a 255aH AGM, 300w of solar, and a 60A DC to DC charger for reference. Our bank never went under 80%. I’m assuming we will use twice as much electricity in the momentum vs the van but it’s still potentially overkill. Aside from an annual trip to British Columbia we are in the western US where sun is plentiful.

[acoleman43]

hah! I thought I was making it less complicated. Less rewiring to do, less to hook up to house batteries, and if I’m adding solar I will likely have to run some larger cable than 10awg as well. They don’t appear to have went out of their way to make the cable runs as short as possible. That’s a bummer about what’s directly above that exterior storage, I guess I wasn’t paying close enough attention.

as for panels are you aware of any 300w panels with a matching voltage that I could pair up with the existing jamboni?

Look at the NewPowa 160W panels. If you connect a pair in series they match amperage and are only 0.21v difference. I have 4 of those (series/parallel connections) to get 940W.

As far as wiring, if you have the (2) 300W Jaboni panels (or one 300W Jaboni paralleled with the two 160W Newpowa in series) a 12 gauge wire will be fine up to 30' with only 2% loss. (assuming 47 volts and 18.6 amps). That would make things much easier and no new holes in the roof for wiring.

[NickinCO]

Look at the NewPowa 160W panels. If you connect a pair in series they match amperage and are only 0.21v difference. I have 4 of those (series/parallel connections) to get 940W.

As far as wiring, if you have the (2) 300W Jaboni panels (or one 300W Jaboni paralleled with the two 160W Newpowa in series) a 12 gauge wire will be fine up to 30' with only 2% loss. (assuming 47 volts and 18.6 amps). That would make things much easier and no new holes in the roof for wiring.

Thank you. My math shows a voltage difference of a little over 1v which negates about 20w of solar still giving me 600w for a savings of $450. This is my new plan! Do you happen to have an image of your roof to show your panel layout? I was up there measuring yesterday and I think I could wire two of the 160’s in series on each side of the trailer length wise front to back in front of the jamboni. What controller are you using?

[acoleman43]

Thank you. My math shows a voltage difference of a little over 1v which negates about 20w of solar still giving me 600w for a savings of $450. This is my new plan! Do you happen to have an image of your roof to show your panel layout? I was up there measuring yesterday and I think I could wire two of the 160’s in series on each side of the trailer length wise front to back in front of the jamboni. What controller are you using?

I don't have an image. I just drew a real bad sketch on a note pad. The panels are about 26.5" wide. The distance from the edge of the AC to the edge of the trailer is about 37". It leaves you with about 9" or 10" for a walk path. You have about 133" from the 300W panel to the fan over the bathroom. That is plenty of room for 2 of the panels if you want to have both on one side. I have 4 panels so that is 2 panels (front to back) on each side of the AC.

For a controller I have a Victron MPPT 150/100. It's overkill but was planning 1600W initially.

[NickinCO]

I don't have an image. I just drew a real bad sketch on a note pad. The panels are about 26.5" wide. The distance from the edge of the AC to the edge of the trailer is about 37". It leaves you with about 9" or 10" for a walk path. You have about 133" from the 300W panel to the fan over the bathroom. That is plenty of room for 2 of the panels if you want to have both on one side. I have 4 panels so that is 2 panels (front to back) on each side of the AC.

For a controller I have a Victron MPPT 150/100. It's overkill but was planning 1600W initially.

Awesome thanks. Doing some calculations I think I’m going to go all in and order 4 of those panels. On a sunny day that should be able to replenish my batteries (400ah) from nearly zero. Is that what you’re seeing? Are you still using the stock wiring? Looking at an online calculator it’s calling for 4awg wiring for 30’ at 28A to stay under a 3% loss.

[acoleman43]

Awesome thanks. Doing some calculations I think I’m going to go all in and order 4 of those panels. On a sunny day that should be able to replenish my batteries (400ah) from nearly zero. Is that what you’re seeing? Are you still using the stock wiring? Looking at an online calculator it’s calling for 4awg wiring for 30’ at 28A to stay under a 3% loss.

At this point I think I'll keep the stock wiring for the 300W Jaboni. I'm going to run an additional 8 or 10 gauge wire for the 4 Newpowa. I'm estimating about 30' of wiring at 18.6 amps and about 47 volts (worse case at -30 degrees Celsius - wiring series parallel) with 2% loss is a 12 gauge and 1% loss is an 8 gauge. I'll combine both lines in the area under the master closet. If I decide to run a new line, where the factory wiring is (I really don't want to make any unnecessary holes in the roof), it will likely be a6 gauge or 8 gauge wire. But I'd have to remove ceiling panels to do that.....Not sure that's a route I'm willing to go yet.

I'm going with a 24v system so mine will be slightly different from what you're doing. I'll have two 202ah (or 228ah not sure yet) 24v batteries in parallel (equivalent to about 800ah 12v batteries). I'm also installing a second solar charge controller (Victron MPPT 100/30) for an additional 400W of suitcase panels two 200W panels groups) connected in series to an outside port. Total I'll have about 1400W.

Realistically, if my numbers are right, the 1400W will typically generate between 40 and 50 amps when the sun is out (60 amps in perfect conditions). To fully charge from 0 will be about 8 or 9 hours which isn't realistic in a 24 hour period. But I don't think we will be depleting 400ah (24v) each day either so I think we should be fine. My daily energy consumption estimate was about 3000W. That includes microwave, all lights, multiple laptops, phones, appliances, lights, fans, tools, etc - but no air conditioning. Even without any sun we could survive for 5 or 6 days so I think we're good.

[NickinCO]

Bumping this thread as I'm getting closer to doing the install. My initial plan as stated above was to run two NewPowa 160w panels in series at the front of my trailer, then connect them in parallel with the stock 300w Jamboni at the rear. This would create a system that is 32.26v, 9.3a or 600 watts. I could do this utilizing the stock 10AWG wiring. I was emailing back and forth with a shop who recommended I wire all three panels in series since amperage is the same. I was under the assumption due to the differing voltages the system would be limited to the lowest voltage panel - 16.7 but he states voltage will all be accumulative to 65.66 volts and 9.3a. This would give me 610 watts and less loss through the factory 10awg wiring since it's only 9 amps. I know the downside to this is partial shading but my boondocking happens in the desert where there are no trees so it's not really a concern to me. The worst case would be shade from the AC unit. If that indeed would work it has me considering 4 160w panels. Two in front, two down one side of the AC and the factory 300 in the rear. This would give me 920w total and 99 volts / 9.3amps. For both of these options I'm considering a Victron 150/45 charge controller. Any thoughts?

The Jamboni 300w panel specs are
32.26v
9.3a
The NewPowa 160w panels are
16.7v
9.3a

[Country Campers]

It is this solar newbie understanding that in series the voltage is added and the amperage is what ever one panel puts out, 3 panels at 20 v 5 amps would be 60 v 5 amps for example. In parallel the same panels would be 20 v 15 amps (hopefuly I have that correct). You could add a second port on the roof for the 4 new panels and then connect the factory panel and the 4 new panels to the Victron controller, this would allow you to run a larger wire down to the controller from the 4 new panels if you wanted to increase amperage. Still all new to this so these are just thoughts.

Brian

[NickinCO]

The goal is to utilize factory wiring

[howson]

NickinCO -- according to Will Prowse, wiring in parallel the panels must have the same voltage. Wire in series the panels must have the same amperage. Given the specs posted...as long as the MPPT can handle the voltage it seems like a sound plan to me.

My brain's too fried right now to calculate the MPPT...I like Garret's video on the topic. If what you're choosing aligns with his recommendations on how to choose a controller you'll be good. You do want to make sure and get the SmartSolar version--nice to tap in via Bluetooth on the phone via VictronConnect.

[NickinCO]

NickinCO -- according to Will Prowse, wiring in parallel the panels must have the same voltage. Wire in series the panels must have the same amperage. Given the specs posted...as long as the MPPT can handle the voltage it seems like a sound plan to me.

My brain's too fried right now to calculate the MPPT...I like Garret's video on the topic. If what you're choosing aligns with his recommendations on how to choose a controller you'll be good. You do want to make sure and get the SmartSolar version--nice to tap in via Bluetooth on the phone via VictronConnect.

Thanks. I need to decide on whether or not I want 2 160w panels or 4. I'm going to run them all in series now but if I get two (610w total) I will use the Victron 100/50, if I think I need 4 (920w) I will need the 150/70. I think 600 would be more than enough but sizing the system for spring/fall trips when the sun is lower in the sky I want to make sure it doesn't surprise me. The panels will definitely be mounted flat on the roof as well. I need to do a little more research.