Question about solar panels

[Brettmm92]

Hello,

I had a question about solar panels, specifically if they can hook up to the battery that's included on the trailer tongue. Ive never used the battery that came with my TT because it was dead when I bought it. But I noticed that it has specific wiring into the TT. Can I hook a solar panel up to that battery and then possibly use more batteries in a series to power my TT?

If that wouldn't work, where do you plug in battery banks for solar? I've seen videos of TV's that seemed to have extra, even labeled solar power accessories, but mine does not.

Thanks ahead of time for any input!

[Vintage465]

Brettmm92 wrote:
Thanks for all the information!

I definitely plan to get a battery, more so now since the emergency brake function is pretty important.

Another thing that I wish I put in the original question is that I'm aware an inverter is needed to convert the dc power from the panels to ac. Do the travel trailer wires that connect to the battery have their own inverter or something? And where would I install that? I'd imagine that I'd have to fiddle with the wiring inside as leaving an inverter outside sounds like a bad idea to me

I'm seeing some corrections that need to be made to your thoughts and explanations. This statement "convert the dc power from the panels to ac""convert the dc power from the panels to ac" is incorrect as the power is not from the panels. The power is from the battery bank. The panels and controller only charge the batterey bank.

The inverter is or can be done in a couple ways. One way is to wire the 120v side(output)into your 120v system on you RV and has some kind of transfer switch associated with it so when you plug the trailer into shore power it doesn't fry the inverter. Another way is to kind of have the inverter as a stand alone source of 120v power. In either case, you want to get the inverter as close to the battery bank as possible and be real generous with the 12v wire size....Generous is not #6 or #4. Generous is like 1/0, 2/0 etc. This of course depends on the rating of the output of the inverter and how close it is to the battery bank,

[ajriding]

All the questions you asked are answered in great detail in other forum post. Use the Search function and read, read, read. You are just asking us to repeat what has already been asked, but without any details on what you plan, or if you even know what you want. You are just getting tid bits of info on this string...

Is your "tongue" battery the big one, or are you talking about a small hold-in-your-hand battery which would be specifically only for the trailer brakes? You can get a ticket for not having 12 volts at the emergency break-away device for the brakes.

After you read a few post on solar set-ups you can ask better questions if you still have any... There is everything you need to know on this forum

[4x4van]

What are you planning on using the inverter for? Solar panels are dc, your battery is dc, most of your components in the trailer are dc (with the exception of your air conditioner, your microwave, and possibly your TV). Inverters convert 12vdc into 120VAC, and you need a very large battery bank to run anything other than small items from an inverter.

[campigloo]

However you wire it make sure you use the same type battery throughout the system and use about the same age. In your case, new.. Don’t mix 6v with 12v and don’t mix agm with lead acid, etc.
I wired mine separate from the battery that came with the trailer. I have 4 6v gc for the coach and use the 12v only for the tongue jack and emergency brake. I use a trickle charger I got from academy to keep it charged. Works well, I just store it in the propane tank cover when rolling.

[time2roll]

Brettmm92 wrote:
Another thing that I wish I put in the original question is that I'm aware an inverter is needed to convert the dc power from the panels to ac. Do the travel trailer wires that connect to the battery have their own inverter or something? And where would I install that? I'd imagine that I'd have to fiddle with the wiring inside as leaving an inverter outside sounds like a bad idea to me

Inverter can be a bit complex depending on size. Less than 300 watts can be installed easy behind the breaker panel, use the main 12v connection for power, and connect to the panel with a transfer switch.

If you are going 2000 watts you need four batteries minimum and inverter needs to be mounted close to the battery. Then pull wire to the breaker panel, drag your main cord around and plug in direct, or add an inverter outlet in the living space.

Lots of ways to do this depending on your expectations.

[Lwiddis]

"an inverter is needed to convert the dc power from the panels to ac."

Panels charge the battery. The battery supplies the inverter.

[mbopp]

Do you plan to camp w/o hookups? If you're looking at solar it would be a good time to get 2 6-volt golf cart batteries and wire them in series.

[2oldman]

Brettmm92 wrote:
I'm aware an inverter is needed to convert the dc power from the panels to ac.

This statement indicates you're thinking of panels as devices that 'run things.' They don't, they charge batteries, then it's the power from the batteries through the inverter that runs things. Ok, picky picky, but it's really how it works. An analogy is you don't take your paycheck to the grocery store for a loaf of bread, you deposit it in your bank first, then draw from that.

Inverters should be as close to batteries as possible with fat wire to handle the largest expected load on them.

[opnspaces]

Inverters are typically not included in travel trailers until you get up into really high end ones. As far as an inverter it really depends on what you plan to run from it. If you just want to charge cell phones or laptops and such you are better off putting in some dedicated 12V outlets.

Converting your 12V battery power up to 120v only to charge a 5v phone is a very inefficient process. Yes I did it for a while, but since I boondock almost exclusively I finally decided that the losses were too much. I now run several of these 12V outlets wired to my batteries and they work well. The ones I linked are a few dollars more than average. But they were the only ones I could find that did not have a constant LED light on them to keep me up at night. I just pulled power off the overhead lights and ran some 14g wires down to where the outlets were located. I have one on each side of the bed and will soon be adding a few to the kids bunk area.
Link


If you do need an inverter try to find a pure sine wave inverter. The really cheap ones you find online are typically modified sign wave and some electronics are not happy with them.

[Jebby14]

get a new battery before moving the trailer! your brakes need it.

get as many amp hours as you can afford @ 12 volts however you like and then charge it via the converter in your trailer (when plugged in) or via solar or generator through a charge controller into the batter bank. no need for a seporate bank.

[Brettmm92]

Thanks for all the information!

I definitely plan to get a battery, more so now since the emergency brake function is pretty important.

Another thing that I wish I put in the original question is that I'm aware an inverter is needed to convert the dc power from the panels to ac. Do the travel trailer wires that connect to the battery have their own inverter or something? And where would I install that? I'd imagine that I'd have to fiddle with the wiring inside as leaving an inverter outside sounds like a bad idea to me

[Yosemite_Sam1]

Yes, you hook the solar either through a controller (prevent over-charging) or direct to batteries (usually small solar panels for trickle charge keeping your battery charge top. off).

[opnspaces]

Yes you hook to the battery on the tongue. If you're talking a little panel that sits on the dashboard to keep the battery up on a parked car then yes go straight to the battery.

If you are using a more powerful panel then you need to go from the panel to a charge controller and then to the battery.

Since you are referring to a trailer you should always have a fully charged battery on the tongue. This is to operate the brakes through the emergency breakaway switch if the trailer ever separates from the tow vehicle while traveling.

Yes you can hook up additional batteries. But make sure they are hooked correctly. If 12v batteries you hook in parallel. If 6 volt batteries you hook in series for two and series parallel for more than 2.

[time2roll]

You pretty much need a battery to use solar. Yes you can have multiple batteries to have more reserve capacity. Yes connecting solar to the battery on the tongue is perfect. Plenty put four batteries on the tongue and charge with solar.