Solar Panel Layout for Micro Minnie 2108TB

[Fred L]

Im only in my planning / research phase and still havent purchased a MM yet, but when we do, am fairly sure it will be a 2108TB.
I spent some time going through the threads and posts here, but not sure if ive seen a pic of tbe top of a 2108 TB (or if it differs from other 2108's). My question is how many watts (panels of what size) can you comfortably fit on the roof before you max out space. From what I been reading, appears to be either 300 or 400 watts up top.
But not sure if thats 4 x 100 or 2 x 200 or something else. If anyone has a pic of the roof, or could direct me to a thread/post, it would be appreciated.

[Fred L]

Well, barring a pic, would still appreciate it if anyone with a 2108TB or similar, could let me know how many watts they have on the roof and an estimate as to what the max is that will fit comfortable and still allow one to move around and access areas for cleaning and resealing. Thanks.

[creativepart]

Here's the thing... solar panels don't come in one size fits all. Like everything solar, inverter, battery it's all customizable and it requires you to do the research about your specific application.

Also, we don't know what model year TT you ended up with. Did it come with one solar panel from the factory? If it did what wattage is that panel and then how many watts can your solar charge controller take?

So, how about some more info about your plans? What do you plan to do with your solar powered TT?

[creativepart]

I searched YouTube and did find this guys video of his mega power setup on his 2022 Micro Minnie 2100BH.

This seems a bit excessive to me - but hey it's a blank canvas do whatever suits you and your needs.

https://www.youtube.com/watch?v=mZg6F1Yx3Wo

[Decuct CoCo]

I'm of the opinion 12 volt PV systems are a waste.

a 24 volt or better yet 48 volt system is more efficient especially when powering a 2000 or 3000 watt 120 volt inverter..
12 volts can be easily tapped off 48 volt battery bank using readily available voltage converter/reducer..

LiFePO4 3600 watt system I have has 48 volt battery pack charged via shore power or a single 600 watt solar panel I acquired.


As noted panels are of different sizes, wattage, and voltage..
it's quite easy to obtain nearly 800 to 1000 watts of power out of two panels..
https://a1solarstore.com/solar-panel...ar-panels.html

shop around, the following video is of one 48 volt installation and how it integrates with 12 volt RV system.

https://www.youtube.com/watch?v=7iGNl0Vmz7A

[creativepart]

Originally Posted by Decuct CoCo

I'm of the opinion 12 volt PV systems are a waste.

a 24 volt or better yet 48 volt system is more efficient especially when powering a 2000 or 3000 watt 120 volt inverter..
12 volts can be easily tapped off 48 volt battery bank using readily available voltage converter/reducer..

When folks ask about solar it's vital to understand that everyone's needs and desires are vastly different.

While one person may recommend thousands of watts of high voltage PV panels charging many Kilowatts of large batteries feeding 3,000+ watts of inverters to run large 110v loads in their large motorhome. It's best to realize that a great many with a 21' travel trailer have much lower expectations. For them a couple hundred watts of 12v solar recharging their OEM trailer battery is all they are looking for.

That's one of the great things about RVing - it ranges from the small and simple to huge and over the top - and keeping everything in perspective is super helpful for everyone.

[Marine359]

Fred,
What model year are you looking at? If 2023 or later, photos you’re likely to see on the forum will be outdated because WBGO changed the roof venting. There’s no longer a vented range hood over the range. Instead they moved the forward roof vent rearward so it could serve as a stove vent. The YouTube video posted here does not reflect the change. If you’re going to be buying from a dealer, go there and get on the roof and take measurements. The roof is walkable. On my 2021 2108ds, I mounted three 100w CIGS panels, and there was room for a fourth panel. Each of my 100w panels could have been ordered as a 200w panel. CIGS panels are larger than equivalent monocrystalline panels, so you could be confident that there’s room for 4x 200w mono. We found that for boondocking, 400w (300 roof and 100 portable) was ideal for our needs. With a 12v compressor fridge, if you’re frugal you’ll use about 1kWh per day. (Without furnace use). 300w solar yields about 1kWh per day, or basically enough to replace your daily power consumption. Our 100w portable panel was used primarily to charge a powerstation which off-loaded many chores, like phone, tablet, busb devices, and cpap from our main battery bank, thereby extending the number of days we could go with no generator.

[Fred L]

Thanks all for your replies. Right now Im predominantly focused on being able to boondock for a week at a time in cool weather, occasionally down into the 20's at night and be able to maintain sufficient power for a 12v fridge. I have a generator, but I prefer to look at it for back-up only if needed. Our warm weather trips typically are with hookups, so no need for a system to run an AC and we rarely use a microwave, but could run the generator if it was a must.
As mentioned earlier, I still have not purchased a trailer yet, but did attend a show last weekend and did like what i saw in the 2108 DS model they had. They also had a FLX model next to it, so was able to do a brief visual reference and "appears" all is the same, although I know the FLX has the solar and related tech improvements. Show price tag was $29,900 for the 2108 DS and $39,900 for the FLX. Would be interested to see a side by side comp listing what extras you get in the FLX. My sense is $10k goes a long way in a diy environment and has to include a fair amount of labor to get to $10k.

Jim, appreciate you letting me know your details. Pretty much what i was hoping to hear. Ie that I can put at least 600 watts (most likely 3 x 200watt) of panels up top and then add a portable panel if needed, along with a 300amp hour LiFePo4 battery. Understand now too re the vent being moved back.
Most days while boondocking, I typically leave at 9 and return at 3-4:00, and wouldnt leave the portable panel out, so not sure how much of a benefit it will be, so leaving it as an option.
BTW, thinking either a 2021 or 2024 model yr.

[creativepart]

You get more with the FLX than you've said you are looking for. You not only get pre-installed solar panels, but 3x the battery power over the TT in non-FLX form. Plus, you get a capable Inverter/Charger that would let you use many more 110v AC appliances, even the microwave.

So, if you were to DIY all of this in a non-FLX travel trailer you would easily spend $5000+ all in - especially with the Lithionics 320ah battery. That's a sizeable DIY project so this is why it costs twice as much pre-installed. Any DIY install is likely to cost half as much as hiring a shop to do the work.

Right now Im predominantly focused on being able to boondock for a week at a time in cool weather, occasionally down into the 20's at night and be able to maintain sufficient power for a 12v fridge. I have a generator, but I prefer to look at it for back-up only if needed. Our warm weather trips typically are with hookups, so no need for a system to run an AC and we rarely use a microwave, but could run the generator if it was a must.

The question is, would you appreciate all those extra electrical features? You probably would, but that's not what you're saying in the post above. However, once you start using a non-FLX TT you may change your list of desirable boondocking options and want to add batteries, inverters, etc.

[Marine359]

Fred
First off, there’s rooom on the roof for 4c 100w panels, 800w total

Nice portable panels can and will run away from home. We throw our portable on the roof in the empty spot and try to hide the cables.

If you want everything the FLX has you should buy the FLX. It was not in the market when I bought our 2108DS. The FLX Truma components are not available after market. However we upgraded everything else to “near” FLX status for about $4,000 component cost and all DIY labor. If you paid somebody to do the installs, crank in another $4,000 or more. We have the same inverter/charger of the original FLX, same amount of solar, and a somewhat lesser battery. The setup has worked well for us for extended boondocking of 5 days or more. After adding a 2kWh powerstation to supplement our 2kWh LFP we never again had to run the generator. Bottom line is , it will cost you $6,000 less and 40 hrs of work to wind up with a 2108 that’s almost as good as a FLX. If it were me, I think the FLX is worth the extra $10K.

[Fred L]

Agree, the FLX is probably more than I am looking for. And I am also looking forward to doing the install project and knowing its done at least to my expectations.

At this point my list so far is (realize Im missing panel mounting, accessories and wiring cost)
- 250w x 3 Rich Solar panels - $900
- Victron Charge controller 150/85 $450
- 300 amp hr lifepo4 - $900
- 3000 watt inverter Renogy - $380
- Victron Shunt - $120

So "very" roughly $2750 and an additional $1000? for wiring/mounts/fuses/etc.
who said $4000 Jim....
What am i missing?

If the budget is $4000, i may put the extra $250 in an upgraded battery.

With 750 watts on top, would i need to upgrade the converter to lithium capable, or would the panels top off the batteries? Will most likely upgrade if I get a 2021 yr model, but not immediately.

Still a project in the making. First I need the trailer.....

[Marine359]

Fred,
Here were my numbers. Keep in mind this was three years ago when battery prices were higher.

Victron 100/30 controller $250
Victron 75/15 controller $140
Victron smart shunt $150
Bigbattery 170ah LiFePo4. $840
Xantrex 2000w inverter/charger w/gfci and remote panel $900
Pre-cut cables with terminals $150
50ft 30 amp SP cable for ac hookup to inverter/charger $60
3x 100w BougeRv CIGS panels $780
100w Folding soft portable panel $140
Fuses, breakers, bus bars, and fuse block $100
Ecoflow Delta 2 Max powerstation $1,600

So, my total was $5,110 BUT
Note my cost for LFP and powerstation total $2,440
Together they gave me 4kWh, or about 400wH more than the 300ah Lithionics in the FLX.
Since you probably don’t need or want a big powerstation, today you can buy 3x 100ah LiFePo4 with low temp protection for $750 total. So subtract $2,440 from $5,110 for my setup, and add $750 for the 3x LFP, and your total will be about $3,500. But that’s only if you do all the work yourself. Not a cakewalk.

BTW: I highly recommend an inverter/charger. It makes life so much simpler and less failure prone. Lots of ac power always at the ready, but maybe more importantly, lightning fast battery charging. If you get a 3,000w model to charge 3x 100ah LFP, you’ll be able to charge at 100 amps. That’s 3 hours from zero to 100% SOC for all three batteries. And that my friend is a BFD.

Of course killer solar setup would be 4x 200w 10bb mono panels wired in S/P. If you can do three, you can do four for just a few bucks more. No extra wiring cost. Also note, I do not include any cost for mounting, as my panels do not require mounts, and no roof penetration.

[Marine359]

One other thing Fred,
Think twice about buying a Renogy inverter.
I’m just sayin. Lots of issues like insufficient pass thru and low sustained output.
Better to ante up for Victron or Xantrex. IMHO
And I hope you’re aware that many 300ah LFP do not have a 300 amp bms, so without sufficient amperage output, you’ll not be able to drive an inverter past the bms limitations. Normally 100ah LFP have 100 amp bms, so 3 of them gives you a full 300 amp output. Also, be aware you’ll need very thick cables, probably 2/0 or 4/0, which are very expensive. We found that a 2000w inverter output was way more than enough for our needs. Will power every ac appliance including the A/C, and can live with smaller cable.

Oh, and did I say you’ll be way happier with a high amperage charging system? You will regret it if your charger is wimpy or can’t be switched to LFP profile.

[Fred L]

Jim,

Noted on the upgrade on the inverter and downgrade to 2000 watts. Frankly I hardly ever use 110 a/c when boondocking. Possibly hook up the TV and DVR if its bad weather and im bored. Or to charge a laptop. Also thinking about Star Link so I can work on down days. So yes a quality 2000w inverter is replacing the Renogy. In a future use, may want to run air con, so good to know I can also use it for that with upgraded batteries.

A little insight since i have been out of RVs for 4 years and a lot has changed. Used to be that I bought a small less expensive pure sine wave inverter, and connected it to the battery and ran an extension cord into the RV.
Im apparently behind the times... noted you referring to them as inverter/chargers. Im not piecing together the working relationship with the charger part of that and the job the trailer converter does?
Ie, the solar charge controller converts solar power to the 12V battery. The trailer converter converts 110a/c to 12V for the batteries and to power the DC aspects of the RV. What does the charger aspect of an inverter do ?
Second question, re these inverters that you note, are they something that is installed and connected to the trailers converter, to automatically power the 110 A/C outlets and appliances in the trailer ? or am i still running an extension cord.

[Marine359]

Good questions Fred

First, you cannot run the roof A/C from the inverter unless you first equip the A/C compressor with an easy/soft start. This device reduces the start up current of the compressors and adds current gradually. The devices are highly effective. And the device also makes it possible to run the A/C using a small 2000w generator. $250 and easy install.

Since you know what a converter/charger does, and you know what an inverter does, and you know what a charge controller does, inverter/chargers should be easy for you to understand in function and in installation. An inverter/chargers does what the name implies. It inverts and it charges. By using one, you get rid of your charger and have no need for a separate inverter. You also don’t need a transfer switch because that function is built into the inverter/charger. Wiring is the same as if you were installing an inverter, except since there is no transfer switch, SP goes directly to inverter/charger input, and ac output goes to panel. This is the hard part and best left to somebody who knows how to do it. The device should be mounted as closely as possible to the battery bank. The greatest additional value is the charging function. Both Xantrex and Victron 2000w models can output charging amperage of up to 80 amps (huge), and both have Bluetooth, enabling you to change parameters in an app from your cellphone. Victron is the gold standard and costs slightly more than Xantrex. But the Victron is much larger and would have given me unnecessary mounting and ventilation problems. The Xantrex went in easily and vent well through its dual fans because it can be mounted sideways. IMHO, you’ll wind up spending almost as much buying a top brand inverter, charger, and transfer switch. All that being said, new Winnebagos come with the newer WFCO with battery type ID which adapts to LFP. But I think the output is limited to 50 amps, and WFCO is crap. But you’ll have to decide yourself whether to stick with the WFCO, and save some money by just installing an inverter and transfer switch. If you do that, stick with a Xantrex or Victron inverter. All the cheap Chinese brands are crap. People will stand by their Chinese brand purchase, but that because it hasn’t failed on them yet or started a fire. I guess you can say I’m a little brand biased.

[MicroMinnie]

Previous rig 2108

[MicroMinnie]

Previous rig 2108 , could fit 4x200 easy
kept it at 3 as 4 becomes hard to walk around it

[Marine359]

For a 600w setup, I recommend:

2x 200w CIGS panels connected through gland to 100/30 controller. You can walk on them. And there will be room for 2 more in future.

1x 200w portable panel connected though a sidewall SAE port to a 75/15 controller. I always favor having at least one portable panel because you’ll sometimes be camped under tree canopy, so roof panels alone won’t cut it. With mppt near battery, you can place the panel 30ft away with virtually no voltage drop. I always recommend doing the portable first before installing roof panels. You may decide the portable(s) are enough and you don’t really need roof panels. We throw the portable on the roof and hide the cable behind the awning upright when we leave the camper. Hasn’t been stolen yet.

The CIGS panels cost twice as much as mono panels, but you install them yourself in 30 minutes or less with never any worry about a roof leak because they don’t penetrate the membrane. Net cost of CIGS is way less than mono panels professionally installed.

[Fred L]

Jim, Ive been researching the CIGS and they make comple sense to me. May do 3x200 and also get 1x200 for a portable set up on a 1/4 in piece of plywood. But need a trailer first Also on board with Victron. Not quite there with the inverter charger yet.

[Marine359]

Originally Posted by Fred L

Jim, Ive been researching the CIGS and they make comple sense to me. May do 3x200 and also get 1x200 for a portable set up on a 1/4 in piece of plywood. But need a trailer first Also on board with Victron. Not quite there with the inverter charger yet.

Hi Fred,
3x200 + 1x 200 CIGS is a lot of dough. I would not do a CIGS as a portable, because for about the same bucks there are some pretty good folding 200w portables out there. Ecoflow makes a 200w bifacial that outperforms every portable on the market. I always recommend that you connect a portable through a sidewall SAE port to its own separate dedicated charge controller. A 75/15 mppt does the trick for that chore. Then, another controller wired to the roof panels. If you’re set on CIGS, you have to ensure you don’t exceed the voltage limit of the controller. CIGS have a very high Voc. Of course, you should run the numbers. If you’re going “big” on solar as you described, it may be more economical to go with a lesser panel, like flexible fiberglass. Not as good as CIGS, but less money, and it may not matter about a 20-20% loss in daily production versus CIGS. There is a great video on “RV with Tito” on how to mount flex panels to prevent overheating. Of course CIGS do not get hot, but any panel using mono cells does heat up, so I would not recommend taping mono flex directly to roof. Good luck on your project.