New Solar Install

[rarebear.nm]

Bobby, to the best of my knowledge any of the various RV batteries do not have a "memory" issue as to charge level. Technically lithium batteries may have memory functions built into their computerized control systems, but not in the battery itself.

Thus there is no need to ever run your battery down to exercise it. It's much more important to keep it at or very near full charge.

Lithium batteries can be safely discharged to much deeper levels than lead acid batteries. Typical numbers I see is 80% to near 100% discharge, depends on model.

AGM batteries can usually be discharged to 75% to 80% of capacity.

Hope this helps you a little. For some serious reading about all aspects of batteries go to https://batteryuniversity.com/ . You can spend seemly endless amount of time wading through their information. But they have good answers to most typical questions.

Have fun and be safe....

[Bobby F]

Originally Posted by rarebear.nm

Hope this helps you a little.

It does, a lot, thank you much.

[geordi]

You do not need to "exercise" the lead acid batteries, but AGM should NOT be discharged any deeper than you would for a flooded lead acid! They can accept a higher charge rate, but otherwise are functionally the same as a flooded battery - except they are usually completely sealed and cannot be refilled if you overcharge them and cause them to gas off hydrogen. They can be tipped over safely where flooded can't for obvious reasons - but they are the same basic chemistry. Treat them like flooded and they will last longer. Pound them, and they will die sooner.

[Vintage465]

I've found the most important thing about Solar is we are seldom talking all in concert. You can have all kinds of watts on hand, but if it is not delivered to the charge controller in a healthy fashion(BIG CABLE-shortest distance) and the controller isn't as close to the battery as possible then all the watts don't help much. I don't run a microwave or even have an inverter. But I run my furnace on winter nights (07degrees to 30 degrees) to keep the tanks and water lines from freezing. Usually have 75-80% left from a 4-6v bank. Usually will charge fully to 100% by 1100hrs. A few clouds, it may take me to 1300-1400hrs. On one cloudy day it only came up to 90%. You can make up for not having sufficient conductor size by wiring you panels in series if your controller is up to the task. Currently I have 3-150w panels, gathering at a combiner box on the roof, then 17' of #4 welding cable to a 30a pwm type controller that is 6 feet from the battery. I ran #2 that 6 feet to the batteries. No MC4 connectors anywhere. Considering the low rent 30a pwm controller I have, I have zero complaints and never run out of battery no matter how long we boon dock

[geordi]

Wiring is certainly important, but you probably could have gotten away with using 16 gauge if you wired them in series from the panels to the controller. I have my 1020 watts in series and using 12 gauge to the controller - I only selected 12 b/c I happened to have some SOOW laying around and it was the right length. That ends up being 1020 watts at 150 volts, well within the capability of the wire with virtually no loss.

The lower your voltage, the higher the potential losses. That's why you want the controller so close to the batteries. Mine is right next to the batteries and there, I'm also using 4 gauge which is more than capable of carrying the 85 amps without losses. Victron has a downloadable wire size converter Excel sheet that will tell you what kind of system performance you could expect with x size and y distance with Z wiring.

Your system would probably benefit greatly from swapping to a decent MPPT, the PWM systems are "just OK" but for maximum capture, you can't go wrong with an MPPT.

[jcussen]

Originally Posted by geordi

Wiring is certainly important, but you probably could have gotten away with using 16 gauge if you wired them in series from the panels to the controller. I have my 1020 watts in series and using 12 gauge to the controller - I only selected 12 b/c I happened to have some SOOW laying around and it was the right length. That ends up being 1020 watts at 150 volts, well within the capability of the wire with virtually no loss.

The lower your voltage, the higher the potential losses. That's why you want the controller so close to the batteries. Mine is right next to the batteries and there, I'm also using 4 gauge which is more than capable of carrying the 85 amps without losses. Victron has a downloadable wire size converter Excel sheet that will tell you what kind of system performance you could expect with x size and y distance with Z wiring.

Your system would probably benefit greatly from swapping to a decent MPPT, the PWM systems are "just OK" but for maximum capture, you can't go wrong with an MPPT.

Agree, I am running 120 volts through a 150/70 amp mppt controller on one string and 60 volts to a 100/30 amp mppt controller, both 10 gauge which is overkill. Could not even imagine running 4 gauge from my panels down to solar controllers. On the house, 2 strings of 2600 watts each with 8 gauge to 250 volt controllers.

[Vintage465]

Originally Posted by jcussen

Agree, I am running 120 volts through a 150/70 amp mppt controller on one string and 60 volts to a 100/30 amp mppt controller, both 10 gauge which is overkill. Could not even imagine running 4 gauge from my panels down to solar controllers. On the house, 2 strings of 2600 watts each with 8 gauge to 250 volt controllers.

When I was revamping my Solar setup I chose to go with #4 so I could experiment with Parallel Vs Series in the future. There is so much conflict between the Parallel-ers and the Series-ers, it's like the discussion between Gassers and Diesels or the Cummins Vs. everyone else. Once I get an MPPT controller I can mess with either series or parallel and come to my own conclusion. As it sets now, I lose nearly nothing with the 17 feet of #4 pushing the 20-ish volts down to the controller. From here upgrades will only get better!

[jcussen]

Originally Posted by Vintage465

When I was revamping my Solar setup I chose to go with #4 so I could experiment with Parallel Vs Series in the future. There is so much conflict between the Parallel-ers and the Series-ers, it's like the discussion between Gassers and Diesels or the Cummins Vs. everyone else. Once I get an MPPT controller I can mess with either series or parallel and come to my own conclusion. As it sets now, I lose nearly nothing with the 17 feet of #4 pushing the 20-ish volts down to the controller. From here upgrades will only get better!

Will be enlightening when you get your MPPT controller. I have a bluetooth solar controller, and have sat on the roof with a piece of cardboard covering 1/4 of a panel and read solar output on my phone, in both series and parallel operation. For me anyway, the very slight gain in running in parallel was not worth the extra time and money in running big wires. But I have 40 volt panels so could not use a PWM controller anyway. Of course with 4 gauge already installed, you should be able to run any configuration you want.

[Vintage465]

Originally Posted by jcussen

Will be enlightening when you get your MPPT controller. I have a bluetooth solar controller, and have sat on the roof with a piece of cardboard covering 1/4 of a panel and read solar output on my phone, in both series and parallel operation. For me anyway, the very slight gain in running in parallel was not worth the extra time and money in running big wires. But I have 40 volt panels so could not use a PWM controller anyway. Of course with 4 gauge already installed, you should be able to run any configuration you want.

Well the idea of being able to run either parallel or series was my plan. What I'd really like is to get a nice MPPT controller and a Victron 712 to see what is really going on........yes!

[geordi]

Originally Posted by Vintage465

Well the idea of being able to run either parallel or series was my plan. What I'd really like is to get a nice MPPT controller and a Victron 712 to see what is really going on........yes!

Do yourself a favor and stay in the Victron ecosystem. I just upgraded to the Victron inverter and a 712, and decided to get the CerboGX and screen to run the whole thing. It's awesome, now I can see the power coming from the solar and the Cerbo tells the charger in the inverter to back off (preferencing the solar power!) to fill the batteries.

I may have made a mistake in the size of inverter, I got the 2000 and it got unhappy when I was using the microwave at the same time that one of the A/C units decided to cycle - the inverter drops the incoming power at that point b/c it doesn't like the generator change, and it freaked out about the microwave b/c I *think* the fridge and the TV / Apple TV might have put it over the top.

I didn't think I was that close on the power.... But that's something to learn about and just be more careful. I also need to disable the fridge's defrost cycle which is WAY too much of a power user.

[NIACC]

Check out the “Bus Grease Monkey” channel on u tube to see his solar set up. Battleborn batteries, Viturbo inverters and controllers, and higher voltage panels.

[n6medjim]

... I URGE you to read:
https://handybobsolar.wordpress.com/...ging-puzzle-2/


When you're done, read a couple of his other articles.


Then, charge (pun intended!) ahead full steam!

Originally Posted by jrobb911

Just getting a Jayco 22rb and wanting to pick up solar. Looking for confirmation that this will work. We rarely hook up to shore power sites and previously used generator for short runs of the microwave, coffee, etc. New trailer doesn't have generator. I've attached the basic idea of the components. I was going to keep the basic AGM 12v battery the trailer came with as backup and setting up the slide out and awnings, charged from the vehicle as I drove there. Plus the solar controller can charge different types of batteries connected to it. Like a house battery and vehicle battery. Once set up I would plug in the shore power cord to the inverter and defuse the battery charger in the load center, to not create a cycle of charging from the battery to the battery. Also switch to just the lithium battery and turn on the inverter when ever we needed to use the microwave, etc. Any ideas of why this wouldn't work? I am eliminating the need for an automated switch box for shore power this way. Both the solar charger and battery have bluetooth apps to monitor power usage and generation. I would never connect both batteries together.
THanks

[Mded40]

Go bigger!
Your dreaming if you think your gonna run a microwave off one or two batteries
You need 4-6 and at least 50-100 amps of instant charging capability. I have a similar solar system to what you are proposing 370 watts into 30amp controller and 4 125 ah flooded batteries. I have discovered when I’m boondocking I’m using power to run my satellite and tv and outside fridge. That Leaves little left to charge the batteries. Your not gonna wanna switch between batteries all the time.
Double up and save in the long run you will be glad you did. My 2 cents

[mcdade54]

There are a number of good ideas and items to consider here. I also recommend not mixing the batteries and suggest you keep the 12 v wires as short as possible. Keep the inverter close to the battery. I have a similar setup and the only thing I would, change is the panel types. Instead of permanent mount I would use suitcase style or mixed. During the summer I like to put the RV in the shade and the panels are a bit restricted there. Portable panels could be moved to the sun, positioned and then repositioned for max charge.