All things Camp Trailer

[Hickey]

So I have a question for those of you running solar. Does anyone else use any other form of charging? I currently have a 60 amp DC DC charger hooked up to 200 amp hours of lifepo 4 lithium batteries. Currently thinking of adding a couple hundred Watts of solar panels on top. But I have room to run up to 450 Watts of panels if I decide it’s worth it.

My lithium set up can handle 50 A of charging per battery So in theory, I should be able to add a solar controller on top of my DC to DC charger without having to worry about sending too much amperage to the batteries. But I would rather error on the side of caution.

I’m thinking about just running like a 60 amp relay and wiring the solar panels in on a normal closed circuit and then when I turn the ignition switch on, it would disconnect the solar panels from the solar controller allowing just the DC to DC charger to do the charging.

Does anyone see a reason why this wouldn’t work? it seems like some of the solar controllers are a bit picky about how you wire them up, but it looks like as long as I disconnect the panels from the controller not the batteries it shouldn’t matter.

At 450 W divided by 12 V that’s 37 A plus the 60 from the charger would put me right at the 100amp limit. I realize the panels will never see full efficiency and that’s probably not a realistic number. But I do think I would be more comfortable, disconnecting the solar while the vehicles running just to prevent any potential problems.

We run our generator sometimes when we need AC or watch tv during a rainstorm. Anytime that’s running, the batteries are also charging. My solar controller is wired straight to the batteries, and I’m totally unaware of how much is coming from the generator to the barriers while it’s running. I haven’t had a single issue doing that, though.

 

[anderson750]

It’s my experience that all batteries won’t last more than 5-7 years. You will need to replace them no matter what. I bought my last pair at Autozone in Ephraim last year and I’ve been kicking myself for waiting as long as I did (they started boiling). The old batteries were not always maintenance with solar, as I added that halfway thru their life span. The old batteries wouldn’t hold the charge through winter with snow on the solar panels. New batts made it all the way thru winter and stayed at full charge.

I just never worry about the batteries now, and that’s exactly what’s great about the solar on an RV.

When I bought my coach it had 4 big AGM batteries that were about 7 years old. I do not recall what the amp hours they were. Essentially about the end of life. When it came time to replace them in 2021 I could not stomach how much the price had gone up during Covid and went a different route. The Interstate 6 volts I put in my coach have lasted about 3 years. At that time I also added 500w of solar and a Victron controller to mange the solar. My uneducated belief is that AGM and Lithium hold up better to solar than lead acid. I have not been diligent on checking fluid levels and know I have gotten low a couple times on some cells

A friend of mine that has built a few of these super C’s from the ground up is a distributor for VoltGo LiFePo4 batteries. He is selling them to me at cost, so I ordered 2 of the 400ah batteries. If they last the 10 years of the warranty then they will be worth it for me. I am plugged into shore power about 10% of the time so the lack of prolonged battery bank is a total PIA even with the 500w of solar I have.

Going this route is definitely not I would look at for average RV user. We use our coach an average of 20 times a year and only a couple of those times are in a place where we plug into shore power. The more you use it, I would recommend you g with the best battery set up you can. There is nothing worse than being in a situation where you cannot run a heater all night when you need to.

 

[Corban_White]

So I have a question for those of you running solar. Does anyone else use any other form of charging? I currently have a 60 amp DC DC charger hooked up to 200 amp hours of lifepo 4 lithium batteries. Currently thinking of adding a couple hundred Watts of solar panels on top. But I have room to run up to 450 Watts of panels if I decide it’s worth it.

My lithium set up can handle 50 A of charging per battery So in theory, I should be able to add a solar controller on top of my DC to DC charger without having to worry about sending too much amperage to the batteries. But I would rather error on the side of caution.

I’m thinking about just running like a 60 amp relay and wiring the solar panels in on a normal closed circuit and then when I turn the ignition switch on, it would disconnect the solar panels from the solar controller allowing just the DC to DC charger to do the charging.

Does anyone see a reason why this wouldn’t work? it seems like some of the solar controllers are a bit picky about how you wire them up, but it looks like as long as I disconnect the panels from the controller not the batteries it shouldn’t matter.

At 450 W divided by 12 V that’s 37 A plus the 60 from the charger would put me right at the 100amp limit. I realize the panels will never see full efficiency and that’s probably not a realistic number. But I do think I would be more comfortable, disconnecting the solar while the vehicles running just to prevent any potential problems.

If the engine is running and charging the batteries, the solar will back off because the charge controller senses the higher battery voltage and thinks that the batteries are charged. I wouldn't worry about a relay on the ignition, the chargers are smart enough that they will work together (which really means that one or the other will take the lead).

 

[str8axleguy]

So possibly silly question, do the lithium batteries charge well when cold? I know lithium tool batteries don’t like extreme temperatures

 

[Kevin B.]

So possibly silly question, do the lithium batteries charge well when cold? I know lithium tool batteries don’t like extreme temperatures

No, they don't like that at all. In fact, if you're planning on winter use you should have a heating pad or some other method of keeping them warm.

 

[anderson750]

So possibly silly question, do the lithium batteries charge well when cold? I know lithium tool batteries don’t like extreme temperatures

No, they don't like that at all. In fact, if you're planning on winter use you should have a heating pad or some other method of keeping them warm.

Lithium have a cutoff point where they will not charge. Some of the lithium batteries come with built in Bluetooth so that you can monitor them as well as heating pads built into them for cold weather charging. The ideal situation is to have them in an insulated battery compartment.

 

[nnnnnate]

I don’t love these electrical connections. To be fair, they were taped up, but I still don’t love them. Can I solder them instead of using the wire nuts? I also think I should upsize the wire gauge size on the fuse and red wire that will connect to the battery post. The black power wires are 3 @ 8 gauge. I forgot to check what size fuse it had.

I also need to make a connect cable for the 6v batteries. The internet told me I should use 4 gauge wire for that. Any issues there?


I also bought this Noco Genius 2x2 battery charger and maintainer. Its got two banks so you can connect both batteries at the same time. I figure this would be a good option for them to be connected to while at the house and I've had a Noco jump pack for a while and have been really happy with it. It only charges at 2 amps per bank so its not ideal for in camp use off a generator but should be perfect (I think) for off season maintenance.

 

[N-Smooth]

Pretty much any option is better than wire nuts, yeah.

I pull my trailer batteries in the winter and put them on a shelf in the garage. I will throw a charger on them once or twice to make sure they stay fresh. Is it necessary? I dunno... it could easily be another overkill process my dad taught me- FWIW

 

[ID Bronco]

I plug my trailer in during the winter and leave the batteries in it. They still get cold but are topped off, they would be just as cold in my garage. I have no idea if this makes any scientific sense, but they last so I keep up the practice.

 

[Kevin B.]

Can I solder them instead of using the wire nuts?

Heck yes. Solder and heat shrink. Amazon has heat shrink/solder connectors if you want to do it all in one step.

 

[nnnnnate]

I spent $40 buying some wire and battery lugs and glue 3-1 heat shrink. Pretty sure I could have bought the finished cable I needed for $10. That's kind of how we roll though, isn't it.