Questions about trailer solar systems and charging off the tow vehicle, and shore power

[dreadlocks]

nonsense, generally its advisable to not tip your trailer upside down, if you have conditions where you have to mount a battery sideways or something then sure.. never smelled anything coming out of my batteries and them exploding is just nonsense, are you putting your self and battery banks in a sealed chamber while charging? You got better chance of blowing your camper up with your own farts than your FLA batteries since hydrogen is so much lighter than methane.. Despite trying practically every time I've gotten on a Golf Cart, I've never been able to make one explode.. I'd wager its practically a non-event.

real expo guys dont spend 3x more money for zero performance gain.. thats for the mall crawler crowd who just want the stickers and bragging rights.. but if thats the case AGM is old school, Lithium is where the real street cred comes now days.

 

[john61ct]

There are valid reasons for preferring AGM.

Just know the cost per Ah per year will be a lot higher.

Odyssey, Lifeline, Northstar, maybe Full River. . .

 

[dwh]

Normal RV wiring does not usually include an INverter (DC->AC). They normally do include a CONverter (AC->DC).

What the converter does is take incoming AC shore power and output 12v so both the 120vac stuff is powered (by the shore power), and the 12vdc stuff is also powered (by the converter). That way, the battery doesn't get drained by the 12v stuff when plugged into shore power. Since the converter is putting out 12vdc (more like 13.6v or somewhere in that neighborhood), there is a mild charging effect to the battery...but most converters aren't actually very good battery chargers...but, some are. Just depends on what you have.


That on/off switch sounds like maybe a master disconnect for the battery.

 

[dwh]

Depending on what converter you have, there are kits to upgrade it to a proper battery charger.

 

[dwh]

And if you don't actually need AGM you are way better off with golf cart batteries.

(And FLA can and do spontaneously blow up. But it's rare enough to not worry about it. EDIT: AGMs can do it too.)

 

[dwh]

 

[dwh]

It has nothing to do with hydrogen buildup in the area outside the battery. All it takes is hydrogen and oxygen INSIDE the battery...and an internal short.

 

[dreadlocks]

and that kinda damage requires very high charge or discharge rates, that might be an a slight concern if your trying to run your aircon off a battery bank.. its never gonna happen powering a fridge, some lights and a furnace unless your really negligent and dont put any fuses on anything.

Can anyone raise your hand if you've ever had a battery explode?

Yes in some situations AGM has benefits, but what about all wild claims they make, like you can discharge em to 20%, or they last longer, or they charge way faster? eh snake-oil.. you cant, they wont, and its marginally faster.

 

[dwh]

Actually, most lead-acid battery explosions seem to happen due to being left on a charger for a long time, running low on water and leaving the plates exposed.

That orange battery was a sealed "maintenance free" according to the guy who posted it...in a boat, stored, hooked up to a high-tech charger.

https://www.thehulltruth.com/boating-forum/270144-battery-explosion-need-advice.html

 

[dreadlocks]

well all deep cycle batteries that I know will eventually fail spectacularly if negligently charged, even AGMs.. kinda a known danger of energy storage, applies to much more than batteries too.. dont want to overfill pressure containers or fuel tanks either.

 

[john61ct]

If you are tuned in to your bank, you should be replacing it long before acute failure signs start showing up.

Standard EoL is 80% SoH, might push to 70% but past that is increased odds of such unexpected "events".

Proactive maintenance trumps waiting for components to overtly fail.

 

[Pastryslayer]

Maybe some photos will help. DWH was half right, its a main battery disconnect, not a breaker. But it has an inverter, not a converter.

I'm 90% sure the controller goes dark when I throw the main switch.

 

[john61ct]

The inverter is a standard cheap-Chinese yes better than most in that price range,

but can be ignored for now, just another load device, not integral to your charging / control setup.

 

[john61ct]

So first task is, select the new battery bank and decide where it will be located.

Then measure the wire run, from where you tap into the Starter / alternator circuit, routed path back to the Anderson plug connection you'll need, and from there to the bank's posts.

Use a piece of garden hose to simulate the cable routing, get it as accurate and short as possible, but not too short, so you can get a custom crimped order - where are you, north america?

Have you got a battery monitor / Ah gauge, or at least an ammeter of some sort?

 

[Pastryslayer]

Piece of cake. The bank will go just to the right of the nest of wires in the last photo. That's where the old ones were, held by a tie-down strap. The cables to the anderson plug will run about three feet to the right of that, where there is a hatch on the opposite side of the trailer. If I ever decide to charge it off the jeep, I'd pull up close enough to run my long cables with anderson plugs on both ends from the connector on the front of the jeep (for the winch) to the one on the trailer bank. Right? To be honest, based on this thread I don't think I'll be charging off the jeep much. My intent is to keep it on a charger in the garage and rely on the solar when we are out and about, shore power when available. But when I bought the cables, terminals and anderson plug for the winch it was fairly cheap and this battery store cut and crimped them all for me. So I may as well have the option as a cheap backup.

BTW if it means anything to anyone the solar system is built by Mobilite, the parent company of Borderland Trailers. The old batteries were under their label as is the solar panel. They mostly built solar powered lighting and comms trailers for oilfields and such, per their website.

On Saturday I'll get the new batteries and trace all the wires to see if I can figure out the sequence in the solar system. I suspect it goes from the solar panel to the controller to the battery. I need to figure out how the shore power hookup plays into this too, if it just runs the 110 outlets or what.

I'm in NA, yes, Washington state (top left corner, the wet part). And I think I have a multimeter somewhere, but never really knew how to use it.

Thanks again for all the assistance. I'm slow, but I do learn.