Adding Solor to old HiLow & Wiring Upgrades

[FixitandLizard]

Hi all,

So I'm adding some solar to my "new" (older then me) HiLo. I got a pair of 100w glass panels, plus the install kit (charger, cables, connectors, ect) so I think I have everything. And I'm not worried about the weight of the panels, they're very light and I have the old wood roof; I've actually walked all over it when I bought it to shovel snow off, so it's very sturdy.

What is the lest-painless-but-safe way to run the wires from the panels into the top half (where the panels sit) and down into the bottom half (where the batteries live). I really rather not pull wall panels off...

Also, what is the best few ways to anchor the panels without them blowing away when driving? Drywall anchors, just screws, molly bolts?

I'm also in process of replacing wires, adding new items, and cleaning up the old stuff. So far I have a battery cutoff switch between the batteries and the lift motor and main-in, added a 7-way junction box to the 7-way cable connections (lights, power, brake, ground), I will change the old thermal auto circuit breaker to a newer manual resetting/ cutout circuit breaker, and I'm going to mod (cut) the battery box to fit 2 parallel batteries instead of just one.

I also got an idea from another thread... I'm thinking about adding a "remote jump stud" to the outside of the battery box, then adding the connection point to the switched side of the battery cutoff switch. I think this will solve 2 things: when the switch is off, voltage is not present at the stud to reduce shorting risk... And if I have a battery failure and the top is in the "down" position, if I switch the cutoff to off then apply a jumper source to the stud, the drain of the failed battery would be not present and I could effectively lift the top.


Thoughts?

 

[FixitandLizard]

Before Pics of our battery/ pump box.

 

[JackandJanet]

Fixit, you've got some good ideas and I like what you have planned for "emergency lifting".

For ideas on how to secure tempered glass panels to the roof, look at the thread by f4mnect here: https://www.hilotrailerforum.com/f28/my-400-watt-solar-set-up-7105/ where he added 4-100 Watt panels to his roof. I think you should do something similar. As I recall, he used a very strong tape under the mounting frame in addition to screws to secure the top to the frame. I would NOT depend on screws alone to hold it!

You can also, of course, look at the thread where I discuss adding 3-100 Watt flexible panels to the top of mine: https://www.hilotrailerforum.com/f28/my-new-200-watt-solar-installation-now-300-watts-4354/ In my thread, I give some opinions on how to wire the panels (series vs parallel), the wire sizes needed, the type of charge controller I prefer, and how I routed my wires from the roof to the lower half. I would NOT try to run the wires inside any of the wall above the lower half. If you think about it, since the top overlaps the lower half when down, it would complicate the connection between the two. My wires simply run along the inside wall of the upper half and then "loop" when the top is lowered, much like the way the OEM wires to the top inside the bathroom do.

I've been very happy with my solar setup.

- Jack

 

[campthewestcoast]

I added solar to my 2206 towlite I ran the wiries thru the roof at the location of the wire loom of the upper half then ran the solar wires with the wire loom down thru the rear cabinet then under the trailer next to the frame then up to the battery box mounted the charge controller next to the battery in a waterproof box but you need to run two wires +&- 8 gauge wire so you don’t have voltage drop I ran 10 gauge since I only have a 30 watt panel for trickle charging
I also built a larger battery box out of specialized pvc coated sheet metal to hold the hydraulic pump and 2 group 27 deep cycle12 volt batteries added studs for jumping in a separate box under the frame which was in plastic

 

[FixitandLizard]

Excellent ideas, thank you.

Just to keep thinking, what about drilling though the entire roof and securing the brackets with long bolts and washers? I really like the big bracket that F4mnect made, but I can't afford that. With the instal kit, it came with little Z shaped brackets about 2 inches wide and one hole.

So I can totally see the benefit of adhesive tape or adhesive goo, but these relying on just adhesive in these little tabs is a big gamble.

So it looks like my anchor ideas is...
-Sheet metal screws.
-sheet metal screws with adhesive tape.
-long bolts drilled all the way through with big body washers.
-bubble gum and duct tape.

 

[JackandJanet]

If you go all the way through the roof and bolt it with big plates or washers on the other side ABOVE THE CEILING (which is soft), I'd think that would hold things ok. But, you're going to have to get above the ceiling panels to make a sound mount.

I'd also try to keep the wire runs as short as you can, to minimize resistance.

- Jack

 

[joule]

Could you use 4' aluminum T-track and attach to the roof with 3-M VHB tape. And also use a few screws through the T-track into the roof as added safety. That would give a larger surface area for the VHB tape instead of relying on the small surface area of the z-brackets alone. Then use the z-brackets to attach the panels to the T-track. This gives the added benefit that you can easily remove the panels from the T-track to clean and seal the roof in the future without disturbing any caulking or screws that are in the roof.

 

[JackandJanet]

joule, I'm sure that would work. Yes, if you have a large surface area for the VHB tape, it will hold well and screws into the roof will prevent any minor lifting that would weaken the tape bond. Additionally, the tape will waterproof the holes made by the screws.

- Jack

 

[caliphat71]

VHB Tape

I have a 2010 with aluminum roof. I used 3M Very High Bond tape and stuck the aluminum brackets on the roof and then bolted my 4 100Watt aluminum framed panels to them. Been over a year and a dozen trips up to grand canyon, flagstaff and back. Still solid.

 

[tcongdon]

I have a 1994 21' HiLo FunLite 9421FLL that I would like to add solar to mine. I was looking at the flat roll panels that you can use the Eternabond tape to hold them in place. But I have no clue how to do any of the other stuff. Read several books but still lost. Sounds like you know what your doing and some great ideas.

 

[FixitandLizard]

Sure, what do you want to know? Devices, how things hook up, voltages and amperage and ohms oh my, way to run wires?

 

[tcongdon]

I read a couple of books on RV solar. Some of the questions I have are, Can you still hook up to power if available and if you can is it automatically like mine is now. Flip no switches, just plugin and use both 12v and 110. The second question is can I add to the system later. I would buy the panels now and the main unit and charge my 12v acid Marine Battery and later on buy the Lithium batteries and later buy the 110 converter. Also, can I keep my 12v acid Marine Battery and get some Lithium batteries later and have both? I would also like to know if I put 2 100watts panels on the roof, can I plug in a separate panel in case I am in the shade? Thanks

 

[JackandJanet]

I'll try to answer your questions where I can.

1. Yes - you can still plug into shore power while your solar system is also charging the batteries. Solar controllers will keep you from overcharging the battery just like the trailer's converter does. You won't have to do anything special when you plug into shore power. The 120V and 12V circuits in your trailer will both work.

2. You can certainly upgrade your system later. However, I would NOT connect a lithium battery to an ordinary lead-acid battery in the hopes of increasing capacity. Batteries that are connected in parallel, to essentially create a larger, longer energy producing battery should both be the same size, same type, same age, and ideally, the same brand. But, you could easily replace your lead-acid battery with a lithium one. You MIGHT have to upgrade your solar controller and your trailer's converter though, to charge it properly.

3. You can have both lead-acid and lithium batteries, but they would have to be "separated" - you would buy a battery isolater for that purpose (essentially a "switch") so that you would be working with one or the other, but not both on the same charging circuit.

4. Yes, you can have an independent charging panel that you could put in the sun if your roof panels were in the shade. It would have its own charging controller and it will work in harmony with your roof panels and/or shore power.

5. A question you did not ask - can your roof panels be used when your are towing? Yes, they will work in harmony with your tow vehicle's charging system because the roof panel's controller adjusts the charging current appropriately.

6. I recommend you get an MPPT controller, rather than the cheaper PWM controller. It will charge your batteries more efficiently in all kinds of lighting. I THINK an MPPT controller may work properly with lithium batteries too, but you would have to look at the specs on it.​

Hope that answers most of your concerns.

- Jack

 

[tcongdon]

Thanks for the information.

So I would have to replace my trailer converter in order to do solar? Also what about wintertime. Would I still need to plug in or would the solar be enough to charge when snow and cloudy days when the temperature drops?

 

[JackandJanet]

No, sorry I confused you! You would NOT have to replace the trailer converter to add solar. You MIGHT have to replace it though if you change your onboard batteries to lithium ion. Those kinds of batteries take a more carefully controlled charging rate and I suspect your present converter does not supply that charging procedure.

Personally, I would NOT try to install lithium ion batteries in a trailer. They are VERY expensive (costing 7-8 times what a lead-acid battery costs) and I don't know that they have a particularly better useful lifetime, unless they are maintained VERY carefully. I think you can get more benefit by installing two lead-acid 12V batteries in parallel (or two 6V golf cart batteries in series, if your battery box has room for them). I have two Group Size 24, lead-acid marine/deep cycle batteries in my trailer, and the converter and solar charges them just fine.

A solar panel set does need its own charge controller, however, and this is the MPPT controller I recommended. It reduces the uncontrolled voltage from the panels to an acceptable voltage to charge the batteries and reduces the charge rate as the batteries reach full charge to avoid boiling the electrolyte. I have a 20 Amp controller in my trailer for the 3-100 Watt panels I installed. Even in full sunlight, with a low battery state, I've never seen the charging Amps above 14 A.

On a slightly different note, I would NOT recommend other kinds of "premium" batteries either, such as ones labeled AGM. They cost 2-3 times as much as a lead-acid battery and are able to give you a service life that is 2-3 times higher than a lead-acid battery too - IF MAINTAINED PROPERLY! Again, I think it's a bit hard to maintain a battery properly in a trailer, so would not expect them to last that long.

If everything is turned off in your trailer when it is in storage, your batteries need very little charging to maintain them. Of course, if there is snow on the roof of your trailer or it is otherwise covered as mine is, you will need something to replace the small charge decay that occurs over time with lead-acid batteries. I have mine connected to a Battery Minder charge maintainer in storage, since it sits right outside my garage and I can easily plug that device in. Your set of 2-100 Watt panels would easily maintain the batteries if they were exposed to full sunlight at least once a month.

Hope this helps.

- Jack

 

[FixitandLizard]

I'll try to answer your questions where I can.

.......

Hope that answers most of your concerns.

- Jack

Heck, there is some good info here. I learned stuff.

If I was gifted AGM batteries (thanks dad), do I have to do anything special or just plug-and-play to the solor?

 

[JackandJanet]

Fixit - I'm no expert on AGM or Lithium batteries. I DO know that my Battery Minder that I use on my trailer has a special setting for AGM batteries, which is somewhat different than the one used for standard wet cells. So, I conclude they prefer a slightly different charging algorithm. Beyond that, I know nothing, except that you can drop an AGM battery into your car without changing anything. Still, I suspect that charging environment is not optimum.

I think if you have a good charge controller in your solar setup, it will provide the correct charging values. I'd be more concerned with the way your trailer's converter would handle those batteries. I DO know that the modern replacement converters that have been discussed in the forum recently ARE designed to charge AGM batteries correctly. I think they have four different charging stages?

- Jack

 

[FixitandLizard]

Fixit - I'm no expert on AGM or Lithium batteries. I DO know that my Battery Minder that I use on my trailer has a special setting for AGM batteries, which is somewhat different than the one used for standard wet cells. So, I conclude they prefer a slightly different charging algorithm. Beyond that, I know nothing, except that you can drop an AGM battery into your car without changing anything. Still, I suspect that charging environment is not optimum.

- Jack

Optimum

Bumdum, tiss!

Anyways...
The trailer converter is the brown box under the bed, has the fuses for the accessories, and connects to both the 12 volt batteries and the 120 volt shore power, right? Basically a rectifier, transformer, battery charger, and power distribution block in one package? Mine still works, but do I need to replace it?

 

[JackandJanet]

Yes, that's the trailer converter, and yes, that's what it does. If it works, I wouldn't change it. But, it may not treat your Optima kindly. The one in my trailer was installed OEM in 2006, (an Elixer), and it is no longer a brand you can buy. I think the modern ones employ a much better charging algorithm, that I think is designed to charge an AGM battery properly.

So, it all depends on how much you value the gift battery?

BTW, I welcome other thoughts on this. I admit to being somewhat opinionated about the various kinds of batteries and what works well in a travel trailer. My thoughts may well be worth nothing more than you are paying for them.

- Jack

 

[thatguy-HILO]

I've used 3 different batteries i'd rate them

#1 two 6 volt golf cart batteries in series. They hold a charge and charge up fast with solar but are heavy and might need modification to fit in you battery area.

#2 two lithium batteries. Much lighter and if charged/discharged correctly will out last you! Downside is that they are pricey but costs are coming down.Also have to charge it with something Li compatible


#3 the standard battery that came with it (can't recall what size but it was flooded) but I didn't use it for long as it didn't hold a charge (old)