Three 375 watt solar panel for TT...

[theboneskes]

I bought three 375 watt, 40V panels I was gonna use on my house, but then bought 12 new 370 watt panels for my house. Bought 3 Victron 100/50 MPPT charge controllers, have 4 Tesla 250a 24v batteries along with a 4000 watt inverter. Using it for an off grid system for brownouts here in Columbus Ohio, for when we loose power. So far the tests on the system have been great!

So now I have those 3 panels to use on my camper... not sure which charge controller to buy? I know it will he a Victron. Thinking of going with one Victron 150/45 charge controller, or the 150/35. But, at 12V i can only get 650 watts/hr on the 150/45, and 500/hr on the 150/35 maximum. Id be losing around 400/watts an hour or more... what charge controller should I use? Also, Im gonna install a 2000 watt inverter(maybe 3000) to run stuff, especially the fridge when in storage so I can just leave it on 120V. I currently have two 12V deep cycle batteries, and thinking of upgrading to two AGM batteries?? Or whats recommended? I can't use Lifepo4s or anything like that, as in the winter here in Ohio it gets down to 0° occasionally, and wont be removing the batteries. Any help would be appreciated!

[NH_Bulldog]

I can’t help you with the solar question specifically, but in regard to your batteries, you have it backwards; Lithium (LiFePo) batteries are the ONLY type you can leave in place in subzero temperatures if you don’t intend to remove the batteries.

I am unclear if your intent is to keep everything running off solar all winter through an inverter as opposed to shore power, or if that is only during in-season storage? Either way, running through an inverter is not very efficient and might very well require more solar and storage capacity than you are currently contemplating.

[chuckster57]

Originally Posted by theboneskes

I bought three 375 watt, 40V panels I was gonna use on my house, but then bought 12 new 370 watt panels for my house. Bought 3 Victron 100/50 MPPT charge controllers, have 4 Tesla 250a 24v batteries along with a 4000 watt inverter. Using it for an off grid system for brownouts here in Columbus Ohio, for when we loose power. So far the tests on the system have been great!

So now I have those 3 panels to use on my camper... not sure which charge controller to buy? I know it will he a Victron. Thinking of going with one Victron 150/45 charge controller, or the 150/35. But, at 12V i can only get 650 watts/hr on the 150/45, and 500/hr on the 150/35 maximum. Id be losing around 400/watts an hour or more... what charge controller should I use? Also, Im gonna install a 2000 watt inverter(maybe 3000) to run stuff, especially the fridge when in storage so I can just leave it on 120V. I currently have two 12V deep cycle batteries, and thinking of upgrading to two AGM batteries?? Or whats recommended? I can't use Lifepo4s or anything like that, as in the winter here in Ohio it gets down to 0° occasionally, and wont be removing the batteries. Any help would be appreciated!

They make heated LiPo batteries.

[theboneskes]

Im only planning on leaving my fridge on for weeks we go back to back camping(weekend warriors). I have a dometic 8cuft fridge, and think the power consumption is 2.7A or 440W according to their site, which to me is irrelevant, for power consumption. I know some Lifepo4 batteries have heaters built in, but for what I know you can not charge below 32° F, if heated of course they can be, but Im still learning about Lifepo4 batteries.

I dont necessarily need an inverter to run everything off solar, my main intention is to be self sustainable minus running my two AC units, and Microwave(if need be boondocking-if we ever did that- would be nice to run the trailer off solar/batteries), and other small consumption AC appliances-TV, CPAP machines, etc. I have three 1600/2000 watt generators I can run in parralel if I want to run my ACs(yes you can run more than 2 inverter generators together). But, at night or when all that power is not needed if would be nice to be quiet.

I assumed "best" for a RV would be AGM batteries in a situation like mine, as far as I know you can discharge a AGM below 50% unlike a standard Lead Acid battery? I think Lifepo4 can discharge to around 15%? Again, Im asking for help learning more.

[Cheesehead4Life]

Originally Posted by theboneskes

not sure which charge controller to buy? I know it will he a Victron. Thinking of going with one Victron 150/45 charge controller, or the 150/35. But, at 12V i can only get 650 watts/hr on the 150/45, and 500/hr on the 150/35 maximum. Id be losing around 400/watts an hour or more... what charge controller should I use?

With 1,125 watts of panels, you would be leaving a lot of energy on the table even with the 150/45. Consider spending the extra money to take in as much of the wattage as you can. A 70amp controller would take in about 80% of the total wattage, which is about all you realistically see. "Buy once, cry once"

Originally Posted by theboneskes

Im only planning on leaving my fridge on for weeks we go back to back camping(weekend warriors). I have a dometic 8cuft fridge, and think the power consumption is 2.7A or 440W according to their site, which to me is irrelevant, for power consumption.

Don't underestimate how much consumption that translates into. My 8cuft Dometic uses 300w (on 120v) when running, and runs about 50% of the time on an 80 degree day, though not all that full. That translates into about 280 Ah a day, without factoring in any conversion losses. Have a look at this pic of my AC consumption which details the fridge running (ignore the right side of the graph which is when I brought it home from storage and stuffed if full of more food).

[SR71 Jet Mech]

I believe most lead acid batteries only have a charge rate of .2C which would be 25a per battery. If you have two batteries=50a. Three=75a. So the question is…how many batteries will you have? If still 2 then use 2 of those panels and the 100/50 will be fine. If you end up upgrading to LifePo4 someday then get a 150/70 but for now only connect two panels. Even on the sunniest most beautiful day you’ll only see 75%-80% panel production.
This is of course presuming you intend to stay at 12vdc.

[Stircrazy]

you're better off going up to a 150/100 which will give you a bit of breathing room, or at least a 150/75 or 80 as for batteries, are you keeping the rv heated in the winter? or do you shut it right down? If you don't use it in the winter take the LifePo4 batteries out and take them home with you. If you keep it heated, then place them inside the heated space. as far as AGM, don't waste your money, if you are staying lead acid just get cheaper 6V GC batteries from Costco or Sams club

[Dave Gamble]

Off topic but when you said you lived in Columbus, Ohio that caught my eye and then I noticed you live in Grove City. So do we! We live near Norton & Johnson Rd but our daughter's house is by Gantz Park.

Dave & Martha Gamble

[theboneskes]

Originally Posted by Dave Gamble

Off topic but when you said you lived in Columbus, Ohio that caught my eye and then I noticed you live in Grove City. So do we! We live near Norton & Johnson Rd but our daughter's house is by Gantz Park.

Dave & Martha Gamble

Yes, we live off Hardy Parkway... small world isnt it?