Hi everyone the trailer currently has (2) 12v on the tongue of the trailer. I thought about using foam board to insulate the battery boxes a tad. Winter temps here are 30-40f and summer the high 90s. The trailer sees around 5-15 days a year of really hot 120F days while camping in the desert. Just bought (2) 6v batteries and would like to get the most life possible from them. Trailer came with a 150w panel and a "go power" 30amp PWM controller. (2014 forest river)Im thinking about using the 30a PWM controller for a different DIY project and invest in a higher quality mppt controller for the trailer. Hoping for advice on:1. Worth the effort to move the batteries inside the trailer?2. Are there a couple brands/models of mppt controllers that are well respected in the RV world? (i supplement with generator power, and might add another panel down the road. no plans for a huge power bank. guessing around 30amp is sufficient)

I would not put lead acid batteries inside the rig. They give off gases.Your temperature ranges are not that extreme. Keep them charged with a good quality converter.

I should take a pic of a possible location. The bathroom sink cabinet has a panel to access the back of the fridge. Thought about building a little box and have the batteries vent with the fridge. Trailer is on shore power while parked at home. Seems like the batteries get hit with 14.4v every morning and thats not needed since my converter is powering the trailer? Another idea is to store the batteries in the garage. Install them before a camping trip. Probably a waste of time? $200 every 5 years is not so bad. The current batteries only lasted about 2 years. Fully charged my water pump is enough to trigger the low voltage alarm.

Moving the batteries would not seem to me to do anything especially useful for you. The 6V batteries should outlast the 12V ones with basic care; they're a good bit more robust, being deep discharge batteries rather than "dual purpose" batteries that are closer to starting batteries than anything. Do check the electrolyte levels from time to time and add distilled water as needed.Periodical brief higher voltage bursts are good for the batteries in keeping the electrolyte from stratifying and maybe doing a teensy little bit towards keeping the cells equalized. It's certainly not a grave concern. If they are being held there all the time that's a different matter, of course.

wopachop,I suspect the controller is low quality.You don't have enough wattage to go MPPTI'd recommend the Grape solar controller with temperature sensor, sold at Home Depot.

Been reading and watching youtube video reviews. Just learning about mppt. Was eyeing the EPEVER products and liked the battery temp sensor. So 150w is not enough for an mppt controller? For discussion sake even a 10a mppt controller would not match a 150w panel?

Move batts inside trailer worth it? mppt controller rec

bpounds
Nomad
Mar 08, 2019
Hydrogen is lighter than air, and worked great in the Hindenburg. But turns out there are downsides to using it.

Doesn't really matter in regard to the question of placing batteries near the refrigerator. The flue gasses are going to rise up the vent when there is a flame. Bad idea.
Boon_Docker
Explorer III
Mar 08, 2019
Hydrogen is lighter than air so it rises.
wanderingbob
Explorer II
Mar 07, 2019
I believe the gasses from battery are heavier than air and vent downward , I think !
pianotuna
Nomad III
Mar 07, 2019
Do a cost benefit analysis. Buy a controller big enough to allow for added panels.
2oldman
Explorer II
Mar 06, 2019
Good-quality MPPTs are adjustable which makes it real nice if you ever go Lithium! :)
wopachop
Explorer
Mar 06, 2019
I like the increase in efficiency. For me the main concern is getting a quality charge on my brand new 6v. The current PWM controller is only going to 14.3v i believe. Will need to test it again as i forgot most of the results. I do know the current Durecell Marine batteries are 2 years old and already sag under a small load. The previous owner installed them. So the batts that came on the 2013 trailer were not super old before they died. Makes me think the PWM controller on the trailer is not doing a good job as the trailer was mostly stored or on shore power. It keeps them at 13.7v all day long. Thats with the battery disconnect switch turned off.
Boon_Docker
Explorer III
Mar 06, 2019
I don't see the logic either.

I have 200 watts (2-12v panels parallel) of solar and an EpSolar MPPT controller. When set up and tested the system I seen 20+ volts coming from the panels and a 20% + increase in the rated amperage going to the batteries.
bpounds
Nomad
Mar 06, 2019
pianotuna wrote:
mppt may offer about 10% improvement of output in the real world. It is better to use 24 or higher voltage with mppt.

It is cheaper and better to add a 2nd panel than to spend funds on a top of the line mppt.

In my opinion, charge controllers need to include a battery temperature sensor. They ought to have adjustable voltage set points.

The time to switch to MPPT is when you are contemplating 600 watts or more of panels, or if there is no more room to add panels.

You definitely know more about this stuff than I, but I don't follow your logic.

If one already had a PWM controller, I might agree about not changing it to an MPPT without good cause. But if you are buying a charge controller, as the OP says he is, I think it is money poorly spent for a PWM instead of just going MPPT from the start. With a good MPPT, sporting good features, costing little more than $100, is spending $50 on an PWM really smart? That would have to be some squeaky tight budget for that to make sense IMHO.

10% more output isn't something to sneeze at.
pianotuna
Nomad III
Mar 06, 2019
mppt may offer about 10% improvement of output in the real world. It is better to use 24 or higher voltage with mppt.

It is cheaper and better to add a 2nd panel than to spend funds on a top of the line mppt.

In my opinion, charge controllers need to include a battery temperature sensor. They ought to have adjustable voltage set points.

The time to switch to MPPT is when you are contemplating 600 watts or more of panels, or if there is no more room to add panels.
bpounds
Nomad
Mar 06, 2019
Looks like the XTRA has some new features, including IP33 and CE rating (probably related efforts). Also an improved user interface with more buttons. I didn't see anything worth waiting around for really but that's just me.

They are slow getting their new stuff out there. It was the same with the AN version, and took even longer for them to actually update their user manual.