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Should i disconnect my pv system for winter? Solar Trailer

Dadoftheturkeykids

Arc Angel
Joined
Jan 11, 2024
Messages
240
Location
U.s.
Hi, I have a 12v 206ah SOK (non-heated) tied to 3- 240watt panels on my work trailer to provide light, AC tools, tool battery charging and... coffee😎. Here in michigan we are about to be below freezing very very soon. Should I just disconnect my system for the winter? As far as I understand, you can damage Lifepo4 by charging or discharging below freezing.
Any thoughts?
 
Can you insulate and heat the area around the batteries?

Is the trailer purely solar powered or can you plug into the grid over the winter? If you can plug it into the grid, it probably wouldn't take much to trickle in a small amount of heat to keep the batteries warm and from going all the way to 0%.
 
Hi, I have a 12v 206ah SOK (non-heated) tied to 3- 240watt panels on my work trailer to provide light, AC tools, tool battery charging and... coffee😎. Here in michigan we are about to be below freezing very very soon. Should I just disconnect my system for the winter? As far as I understand, you can damage Lifepo4 by charging or discharging below freezing.
Any thoughts?


Discharge is not the problem.
Even by discharge the battery gone make some heat inside.
For the rest if you have a charge that have temperature sensor.
It will not charge a lifepo4 if the temperature is 5 celcius by the battery.
Means your battery will not charge and your battery is warmer inside than the outside temperatuur.

You do need to set the temperature sensor by the battery unit .
Some mppt or charge have beult in or can set a external temperatuur sensor .
Victron mppt do not have temperature sensor beult in.
Those use the Victron battery sensors (its in the maneul)
 
It is purely solar powered, I'm not sure the caveats to keep the battery warm would be worth it. I think kinda scary to run a heating pad 24/7. I did forget all about the temperature sensor that came with my RichSolar 40a mppt😄. I never really played with that, would I run the sensor inside the metal battery casing?
 
It is purely solar powered, I'm not sure the caveats to keep the battery warm would be worth it. I think kinda scary to run a heating pad 24/7. I did forget all about the temperature sensor that came with my RichSolar 40a mppt😄. I never really played with that, would I run the sensor inside the metal battery casing?

Yes you can do that of you set it by the case .
How you do it makes it so that wy using this to your case for water closing or that cable cut by the metal .
You can fine them in a hardware store (usa call that)

See attach files.
 

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Does the battery have low temperature protection built Into the BMS? If so it will protect itself.

The sensor is for temperature compensated charge voltages for lead batteries, does not co trol low temperature charging.


And that is wy i love Victron stuf .
It have that option to shutdown the charge function.
But only if thare is a sensor connect on it .

See attach files
 

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I recommend making your life easy and simply disconnect the battery. Turn it on after the winter and enjoy camping.

If you get a kick out of projects like a lot of us do, build a battery heater insulate it, switch it out, but honestly don’t need to for a stored trailer.
 
If heating the battery over the winter with PV, how are you keeping your panels clean for any snow storms?

I’m guessing those panels are mounted flat?

For me lots of other things happen in winter time, the last thing I need is another thing to check and do each time it snows.
 
If the trailer is to be used in the winter, then by all means keep the system intact. A warming system could be added for maybe $40. It would use the battery as the source of power for the thermostat and the warming pads.

Given the lower production PV in the winter, you may want to add a supplemental charger that plugs into 120v AC.

I don't remove the LiFePO4 battery from my RV. I'm in there at least once a month during the winter working on projects or just getting away from my wife.
 
Hi, I have a 12v 206ah SOK (non-heated) tied to 3- 240watt panels on my work trailer to provide light, AC tools, tool battery charging and... coffee😎. Here in michigan we are about to be below freezing very very soon. Should I just disconnect my system for the winter? As far as I understand, you can damage Lifepo4 by charging or discharging below freezing.
Any thoughts?
I threw a cheapo portable heat pump in mine and it should keep the batteries above freezing if you have at least insulated the walls.
 
How cold does it get there?

I used to live north of Chicago. LiFePO4 batteries can be stored for a short time down to about -20C (-4F). But if it gets colder than that, they can be damaged even if not charging. In Chicago, -4F is a mild day.
 
I put my batteries in a box made of plywood and insulated with 4" of foam, ~R14 ish value. A couple of these stick-on heaters on a chunk of aluminum in the middle of the batteries and controlled by a cheap apartment baseboard heater thermostat.

Edit: Heater runs directly off DC battery voltage, inverters don't need to be on. So far the 240vac rated thermostat has handled it fine. Doesn't use enough power for consumption to be noticed, even in the dead of winter when heating load is highest and solar input is lowest.


Easily keeps the batteries at ~50F and barely draws any power, even in 15F ambient temps.

Very easy to do.
 
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Thanks yall for the great tips. It does get below 0 here, I am more north of Chicago plus we get that lake effect, in the future I will probably go with a heat pump or direct dc heater sounds interesting. But, for this winter I will just bring the battery inside, maybe throw it in with my house battery bank.
 

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