My turn building a system

[Nwcid]

I just picked up our new 5th wheel this weekend and now it is time to start fixing it up. We mostly boondock so batteries and inverter are my first major upgrades. The unit currently has 2 small 12v RV batteries in it. I do have a built in 5500 watt generator.

This is not my first time wiring a system. My last RV was 30 amp, I had a 1000 watt inverter/charger, 450 ah of FL batteries and 500 watts of solar. While the previous RV was only 30 amp and the inverter had a 30 amp pass through I chose to sub panel the inverter so that only the interior/exterior outlets ran off the inverter.

My new RV is 50 amp and I know what I would like, I also know my budget/wife, and I would like some opinions.

My dream would be a Magnum MSH3012, 600 ah of Lithium and ~1000 watt of solar. I also know what that costs.......... I am not opposed to DIY if I have good resources to work from.

Starting with batteries, it looks like I am 3x the cost between AGM and Lithium. I understand that the Lithium can draw deeper and has a more even output for high loads. Right now I can get a 4 battery 450 ah bank for $1075 or a 470 ah bank (if it fits) for $1150. In theory this gives me 225 ah usable and is the same size bank I had before. To go with Lithium I would need a 300 ah bank, and drawing to 80% gives me 240 ah usable costing about $3000. In reality it appears that you should not routinely be drawing Lithium down that far for best life, so add another $1000 for another 100 ah to have 250-300 ah usable. I live in the north so the will be some added cost to building a system to keep the batteries warm, especially when not being used.

For inverter/charging. The MSH3012 runs about $1600. It has a 60 amp pass though and a 125 amp 12 volt charger. I could wire this directly into one side of my current panel. In my last RV I had a Xantrex 1000 watts with 20 amp charger. I can get a Xantrex 2000 watt with 55 amp charger for $750. The downside to this is that I would have to add a sub panel.

My old system served me very well, especially during good solar charging. Late in the evening when using the TV and computer the batteries would start to get low, but they were also 6+ years old. The new RV will have some increased power use over the old one. With AGM I can only get 4 batteries in unless I relocate another pair somewhere.

I will be doing solar at some point, but probably not until next fall.

Any thoughts or guidance would be helpful.

[Ivylog]

OP, AGMs can be mounted almost anywhere as they do not need venting. I’m struggling with the cost of Lion compared to AGM as I have plenty of room because the coach came with 800AH of lead/acid L16 batteries...500 lbs. I’m hoping I can still buy 8 100AH AGM batteries for $800. Will have to build a rack to put 4 on top of 4 as currently I have 4 big/tall batteries. Unlike CountryFit I have not found a deal on individual Lion cells to build my own batteries and from what I’ve read they have to be incased so they do not swell when charging plus a BMS plus keeping them warm plus $$$$.
For now I’m going to pass on Lion as I have plenty of room. If you do not have the room then the added expense may be worth it.

[Itinerant1]

Originally Posted by Nwcid

I just picked up our new 5th wheel this weekend and now it is time to start fixing it up. We mostly boondock so batteries and inverter are my first major upgrades. The unit currently has 2 small 12v RV batteries in it. I do have a built in 5500 watt generator.

This is not my first time wiring a system. My last RV was 30 amp, I had a 1000 watt inverter/charger, 450 ah of FL batteries and 500 watts of solar. While the previous RV was only 30 amp and the inverter had a 30 amp pass through I chose to sub panel the inverter so that only the interior/exterior outlets ran off the inverter.

My new RV is 50 amp and I know what I would like, I also know my budget/wife, and I would like some opinions.

My dream would be a Magnum MSH3012, 600 ah of Lithium and ~1000 watt of solar. I also know what that costs.......... I am not opposed to DIY if I have good resources to work from.

Starting with batteries, it looks like I am 3x the cost between AGM and Lithium. I understand that the Lithium can draw deeper and has a more even output for high loads. Right now I can get a 4 battery 450 ah bank for $1075 or a 470 ah bank (if it fits) for $1150. In theory this gives me 225 ah usable and is the same size bank I had before. To go with Lithium I would need a 300 ah bank, and drawing to 80% gives me 240 ah usable costing about $3000. In reality it appears that you should not routinely be drawing Lithium down that far for best life, so add another $1000 for another 100 ah to have 250-300 ah usable. I live in the north so the will be some added cost to building a system to keep the batteries warm, especially when not being used.

For inverter/charging. The MSH3012 runs about $1600. It has a 60 amp pass though and a 125 amp 12 volt charger. I could wire this directly into one side of my current panel. In my last RV I had a Xantrex 1000 watts with 20 amp charger. I can get a Xantrex 2000 watt with 55 amp charger for $750. The downside to this is that I would have to add a sub panel.

My old system served me very well, especially during good solar charging. Late in the evening when using the TV and computer the batteries would start to get low, but they were also 6+ years old. The new RV will have some increased power use over the old one. With AGM I can only get 4 batteries in unless I relocate another pair somewhere.

I will be doing solar at some point, but probably not until next fall.

Any thoughts or guidance would be helpful.

What you would like is basically what I had installed on our 35' 5th wheel and its has been fantastic. 900 days of boondocking living since April of 2016.

*Elite-GBS 500ah 12v lithium batteries package
EMS Sense Board(s)
1- EMS CPU with Custom RV Programming
1- CPU Harness Cable
1- 500 Amp 50mv Shunt
2- 400 Amp Solenoids, high efficiency coil*
1- 7” TFT LCD Video Display

*8 CTI 160 watt panels_ 2 in series, 4 sets parallel (flat mounted) to junction box
*Magnum PT100 controller
*Magnum 3012 hybrid inverter with ME-ARC 50
*100amp AC sub panel - everything in the 5th wheel except the water heater is running through the inverter.
*Manual trip 48v DC breakers - 50a (solar in), 120a (solar out)

[Nwcid]

Originally Posted by Ivylog

OP, AGMs can be mounted almost anywhere as they do not need venting. I’m struggling with the cost of Lion compared to AGM as I have plenty of room because the coach came with 800AH of lead/acid L16 batteries...500 lbs. I’m hoping I can still buy 8 100AH AGM batteries for $800. Will have to build a rack to put 4 on top of 4 as currently I have 4 big/tall batteries. Unlike CountryFit I have not found a deal on individual Lion cells to build my own batteries and from what I’ve read they have to be incased so they do not swell when charging plus a BMS plus keeping them warm plus $$$$.
For now I’m going to pass on Lion as I have plenty of room. If you do not have the room then the added expense may be worth it.

Basically my thoughts too. At 3x the cost, at the moment, while I like the benefits, I am not sure I can justify them.

[CountryFit]

OP, your dream of system sounds great. It'll serve you well. Since you had experience in solar on previous rig, no doubt you will make your dream come true, soon and easily!

One thing I'd like to comment, is the size of your panels. You said ~1000w. Is it enough to replenish electricity into your batteries during winter time while you are using aqua-hot that the fans are running during nights? Did you consider flat mount or tilting of panels, and factor that into account?

One of the challenges for solar system to work well is how fast it can replenish the depleted electricity. In my case, I normally use about 200ah from 4pm to 9am the second day, with cooking and residential fridge, without counting A/C and toad charging. In winter time, I could use about 300ah when aqua-hot joins the play. With my 1200ah lithium capacity, mostly the battery stays above 80% day by day, occasionally it gets to 75%.

To make up that amount of electricity, you'd need a decent size of panels. Nowadays panels are cheap. When you DIY, the effort and cost are not significant to put a few extra panels on the roof, if space permits. Now you've got my point - install as many panels as possible/max out the space on roof, but not to hinder the access to roof equipment.

I installed 2750w panels and I am happy I did it. It's my understanding that those panels for residential applications have an edge on efficiency and cost basis. Get reputable panels with higher efficiency (mine is 20%) if possible.

Good luck with your project and happy trails!

[Nwcid]

Originally Posted by CountryFit

OP, your dream of system sounds great. It'll serve you well. Since you had experience in solar on previous rig, no doubt you will make your dream come true, soon and easily!

One thing I'd like to comment, is the size of your panels. You said ~1000w. Is it enough to replenish electricity into your batteries during winter time while you are using aqua-hot that the fans are running during nights? Did you consider flat mount or tilting of panels, and factor that into account?

One of the challenges for solar system to work well is how fast it can replenish the depleted electricity. In my case, I normally use about 200ah from 4pm to 9am the second day, with cooking and residential fridge, without counting A/C and toad charging. In winter time, I could use about 300ah when aqua-hot joins the play. With my 1200ah lithium capacity, mostly the battery stays above 80% day by day, occasionally it gets to 75%.

To make up that amount of electricity, you'd need a decent size of panels. Nowadays panels are cheap. When you DIY, the effort and cost are not significant to put a few extra panels on the roof, if space permits. Now you've got my point - install as many panels as possible/max out the space on roof, but not to hinder the access to roof equipment.

I installed 2750w panels and I am happy I did it. It's my understanding that those panels for residential applications have an edge on efficiency and cost basis. Get reputable panels with higher efficiency (mine is 20%) if possible.

Good luck with your project and happy trails!

All very valid points. My rig is 38' and has a ton of crap on the roof already. I have not measured what I can fit yet but I feel like it will be tight.

I do not have an aqua-hot system so in winter it will just be furnace, lights and electronics.

I will be flat mounting. If we were full time I would defiantly consider maxing out my battiest and panels. Since we are just some-timing and hopefully lots-timing soon I will happily supplement with the generator.

[Ivylog]

Unlike CountryFit I have not been able to find a deal on Lion batteries...best I’ve found for 600AH is in the $4000 +\- range delivered. 800AH (8 X 100AH) AGMs should equal to 600AH of Lion power. Last year I bought 100AH AGMs for $100 but they were no longer available. They did have 88AH AGMs for $70 so I’m getting 10 next week. Probably another $100 in cables and straps to install. $800 instead of $4000...5 to 1 so not that hard a decision to stay with AGMs.

The 10 year old AGMs in my Dynasty are still going strong so these new ones may last longer than me although I will be cycling them more...when hooked to time of use power during the winter.

[CountryFit]

Ivylog

A few days ago, on Country Coach Forum, a lady asked me about my lithium and I told her all about mine. That might answer your questions. It's on post #12 of this thread.

Please be noted my install was unique, to my best interest, certainly may not be the best model for anyone else to replicate. at the most it's worth of referencing.

Have fun with solar and happy trails!

[Itinerant1]

I have always wondered when someone says my batteries have lasted 10 years how much did you use them other than being plugged in? How many cycles is that in 10 years? Just using lite loads or is the heavy power use? Just curious.

[Nwcid]

Thank you for the replies so far. I will look at the links, but at the moment it looks like my most cost effective systems for my needs and allow for future growth is the following.

450/470 AH AGM batteries at $1100
Magnum MSH 3012 at $1600
Solar later

This would give me a inverter/charger that can be installed as a direct pass though and is able to be used with lithium in the future if I go that route. It can use the power share function as needed, especially once solar is added.

I am still open for suggestions and ideas. Unless I find some amazing Black Friday deal it will be a week or two before I order.

[rvethereyet]

Take a look at a used tesla battery. For around $1000 you can get a lot of power.

[Ivylog]

Originally Posted by Itinerant1

I have always wondered when someone says my batteries have lasted 10 years how much did you use them other than being plugged in? How many cycles is that in 10 years? Just using lite loads or is the heavy power use? Just curious.

About like I get 10 mpg BUT at what speed and over how many miles.
So, we are half timers that have been plugged in for 9 months of those 10 years and the other 2-3 months dry camp 80% of the time so...600 days dry and usually having to run the generator twice a day...2 cycles with many down to 50%. SO, min 1000 and could be 1200 cycles.

Starting this winter I’ll be on time of use power so my cycles are going to double and in 10 years after 2500+ cycles can I say “still going strong”...I doubt it.

OP, I have never paid more than $1/AH for AGM batteries and I’m a little surprised that I’ll pay 80 cents delivered next week, SO shop around.
One of the last things I’d buy used is a battery although I did trade for a slightly used Prius battery. Not sure why I did not think about going with several of them although they are 200+V.

CountryFit, I’ve found your posts when you were asking about Lion batteries and your 1400 mile road trip to get them...like me and solar, we’ve come a long way. One size does not fit all and instead of stopping at 700W of solar I’m going to find room for 200W more since I have 3 panels...leaving me one spare since they are unusual thin film panels.

[CountryFit]

Originally Posted by rvethereyet

Take a look at a used tesla battery. For around $1000 you can get a lot of power.

Tesla is using lithium NCA battery composed of 80% nickel, 15% cobalt and 5% aluminum oxide. It's known that it contains higher density of energy but has a much higher chance of thermo runaway than LFP. There are a lot of tech articles about it in websites.

[Nwcid]

Originally Posted by rvethereyet

Take a look at a used tesla battery. For around $1000 you can get a lot of power.

It looks like they are about 500ah for a single battery @12 volts. Still cheeper then buying new.

This is something I am going to look into more.