Winterization with lithium batteries and solar panels

[ksfisk]

Winter Is Coming

I live in northern Illinois, where cold weather is quickly approaching. We typically have stretches of weather where it will be well below freezing, and we do get stretches of weather where the temps can fall well below 0. My camper will be stored outside.

I have a 5.0 with two solar panels and two lithium batteries. According to the go power documentation, the battery should not be charged when the temperature is 32° or below.

So...As far as batteries and winterization go… It sounds like, at a minimum, I need to ensure that the batteries are not getting any charge during cold weather.

what steps do I need to take to protect my batteries and my solar controller system? (I am disconnected from shore power) I would implement the battery disconnect so that nothing was drawing from the batteries.

After that, would the next step be to cover the solar panels with plywood?

do I also need to disconnect the solar panels from the solar controller? (I'm not sure how to do that)

the Gopower recommendation is to bring the batteries into a climate controlled environment for the winter. if the batteries are disconnected from shore power and from the solar controller, would it still be necessary to bring them indoors?

if I leave the batteries in the camper and we have a stretch of above 32° weather, could I safely plug the trailer into shore power and top off the batteries?

if the consensus is that it is the best thing to pull the batteries and bring them into a climate controlled environment, what are the steps for safely disconnecting the batteries?

[Centex]

It's not explicitly clear in your post ..... Can you keep your trailer connected to shore power where it is stored for the winter?

If Yes, have you considered using a portable electric heater (one with a thermostat) to maintain above-freezing temperature in the trailer, or is that not practical?

[Brian B-P]

Originally Posted by ksfisk

if I leave the batteries in the camper and we have a stretch of above 32° weather, could I safely plug the trailer into shore power and top off the batteries?

You could, but there would be no benefit to the batteries in charging them unless they had reached a low state of charge. Certainly don't top them off no matter what state of charge they have reached - only charge to something like 60% to 70% charged if they are going to continue in storage.

[Brian B-P]

Originally Posted by Centex

It's not explicitly clear in your post ..... Can you keep your trailer connected to shore power where it is stored for the winter?

If Yes, have you considered using a portable electric heater (one with a thermostat) to maintain above-freezing temperature in the trailer, or is that not practical?

In Illinois? That's a lot of unnecessary heating.
If the batteries were in an insulated box with its own heater, perhaps it would make sense, but it's still a lot of energy.

[Centex]

Originally Posted by Brian B-P

In Illinois? That's a lot of unnecessary heating.
If the batteries were in an insulated box with its own heater, perhaps it would make sense, but it's still a lot of energy.

OK, so the answer is "it's not practical" .... thanks for the continuing education

[ksfisk]

Thank you both.

[alanmalk]

Originally Posted by ksfisk

Winter Is Coming
Yep, even here in Colorado.
...

we do get stretches of weather where the temps can fall well below 0. My camper will be stored outside.
...

Some Lithium brands say store above 0F, others say above -20F.
You may want to check your brand.

But since -20F is not out of the question here in Colorado, I plan to bring them into the garage.

The general consensus seems to be: "Bring them to near full charge then ignore for 3 months. Then give then another charge".
No trickle charge required or recommended.

I would not try to force every last amp into my batteries prior to long term storage. Seems Lithium batteries really don't like to be at 100% for a long time.

If you are worried about disconnecting the batteries - disconnect from shore power and wait until dark. I plan to keep the solar fully connected but have the trailer power switch in the ON position with a bunch of lights turned on. So when the sun hits the panel there is a load on the controller. Again, no disconnections required.

[ksfisk]

Originally Posted by alanmalk

I would not try to force every last amp into my batteries prior to long term storage. Seems Lithium batteries really don't like to be at 100% for a long time.

If you are worried about disconnecting the batteries - disconnect from shore power and wait until dark. I plan to keep the solar fully connected but have the trailer power switch in the ON position with a bunch of lights turned on. So when the sun hits the panel there is a load on the controller. Again, no disconnections required.

I didn't realize that it was better to have them partially discharged for storage, until you and Brian brought that to my attention. Thank you. The documentation from go power indicates that the operating temperature for charging, is 32°F to 131°F. If it's not recommended to charge the batteries when the temperature is below 32°, we will be hitting that temp pretty quickly here, and have plenty of days that are below 32°, which made me think that I would need to cover the solar panels, if I decide to leave the batteries in place in the trailer.

The storage temperature low is listed as -4°F. Below -4° is definitely a possibility here… So I guess the best thing is probably to pull the batteries and bring them inside. I like your idea of disconnecting from shore power and removing them after dark! I never thought of that. LOL.

so I guess what I'm still unsure about, is do I need to disconnect the solar panels from the solar controller, if the batteries are removed and shore power is not connected. Do I still need to disconnect the solar panels from the controller? Is covering the panels enough?

[oldwave]

Originally Posted by ksfisk

I didn't realize that it was better to have them partially discharged for storage, until you and Brian brought that to my attention. Thank you. The documentation from go power indicates that the operating temperature for charging, is 32°F to 131°F. If it's not recommended to charge the batteries when the temperature is below 32°, we will be hitting that temp pretty quickly here, and have plenty of days that are below 32°, which made me think that I would need to cover the solar panels, if I decide to leave the batteries in place in the trailer.

The storage temperature low is listed as -4°F. Below -4° is definitely a possibility here… So I guess the best thing is probably to pull the batteries and bring them inside. I like your idea of disconnecting from shore power and removing them after dark! I never thought of that. LOL.

so I guess what I'm still unsure about, is do I need to disconnect the solar panels from the solar controller, if the batteries are removed and shore power is not connected. Do I still need to disconnect the solar panels from the controller? Is covering the panels enough?

https://www.explorist.life/how-to-wi...trical-system/

What I have read is 60% state of charge is the ideal storage. The link I sent is an easy and cheap solar disconnect. I wired mine right before the solar charger. It was simple.

[ksfisk]

Originally Posted by oldwave

https://www.explorist.life/how-to-wi...trical-system/

What I have read is 60% state of charge is the ideal storage. The link I sent is an easy and cheap solar disconnect. I wired mine right before the solar charger. It was simple.

This is awesome - thanks!

[kavm]

Have you looked at -

https://gpelectric.com/products/100a...solar-battery/

The BMS has over and under temperature protection. So, I’d think that you do not need to do anything. Unless I am misreading it, the BMS should not send charge into the battery.

From what I see, the best thing is to remove them to avoid being subject to very low temperature. That’s not practical for us, but ours is stored in a large warehouse. It is not temperature controlled but it is hopefully not going to get super cold (-4F).

The batteries are in an insulated box, though I doubt if it is heated.

PS: Please do look at the box your batteries are in. The box is held in place with metal posts on either side joined by a piece of wood on top. We found that this arrangement had come apart on one of the two batteries and the nuts were loose on the other one (probably from the travel). It might be worth tightening the nuts, unless you are removing them for the winter.

[Perry Butler]

Every solar system should have a solar disconnect. This is the disconnect installed last week. I now don't have to cover the panels to disconnect the system when it's daylight.

The electrical installed by ETI is basic at best to save money. There should be a minimum of an ANL fuse 6-8" from the positive battery post and a decent battery disconnect immediately after the ANL fuse. I could go on and on about our camper wiring.

Enjoy,

Perry

[oldwave]

Originally Posted by Perryb67

Every solar system should have a solar disconnect. This is the disconnect installed last week. I now don't have to cover the panels to disconnect the system when it's daylight.

The electrical installed by ETI is basic at best to save money. There should be a minimum of an ANL fuse 6-8" from the positive battery post and a decent battery disconnect immediately after the ANL fuse. I could go on and on about our camper wiring.

Enjoy,

Perry

Exactly the one I installed

[ksfisk]

Originally Posted by kavm

Have you looked at -

https://gpelectric.com/products/100a...solar-battery/

The BMS has over and under temperature protection. So, I’d think that you do not need to do anything. Unless I am misreading it, the BMS should not send charge into the battery.

From what I see, the best thing is to remove them to avoid being subject to very low temperature. That’s not practical for us, but ours is stored in a large warehouse. It is not temperature controlled but it is hopefully not going to get super cold (-4F).

The batteries are in an insulated box, though I doubt if it is heated.

PS: Please do look at the box your batteries are in. The box is held in place with metal posts on either side joined by a piece of wood on top. We found that this arrangement had come apart on one of the two batteries and the nuts were loose on the other one (probably from the travel). It might be worth tightening the nuts, unless you are removing them for the winter.

Thank you so much, kavm! That is great news and I had not seen that! Awesome, thank you so much for sharing this!

[ksfisk]

Originally Posted by Perryb67

Every solar system should have a solar disconnect. This is the disconnect installed last week. I now don't have to cover the panels to disconnect the system when it's daylight.

The electrical installed by ETI is basic at best to save money. There should be a minimum of an ANL fuse 6-8" from the positive battery post and a decent battery disconnect immediately after the ANL fuse. I could go on and on about our camper wiring.

Enjoy,

Perry

I am definitely going to be installing solar disconnect that you and oldwave have installed! The YouTube channel that oldwave pointed me to is so helpful and full of good information!
Thanks everyone!

[oldwave]

Its a great channel

[richling]

Solar System

Nobody wants the RV season to end. But when it does, properly winterizing your solar system will ensure everything is in the best possible condition when spring rolls around. It can also save you money — RV batteries are expensive, and proper storage will preserve their performance and extend their lifespan.

Here are the top ‘to-dos’ for winterizing your RV solar system:

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In Cold Climates*(temps below 32F)

• Cover your solar panels with a protective material that does not allow light to pass through. We recommend using a dark-coloured tarp or plywood, with plywood being the best option.

• Label your solar panel wires ‘positive’ and ‘negative’

• Unhook your solar panels from your solar controller

• Fix wire nuts on the positive and negative leads from the solar panels

• Disconnect your batteries and store them inside in a warm, dry place preferably off the floor on something like a wooden pallet. (AGMs can handle temps lower than 20F)

• Check the batteries monthly and charge them if necessary

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In Warm Climates

There is no need to ‘store’ your RV solar system in warm climates unless your RV is parked indoors or in very low sunlight. If that’s the case, simply follow the cold climate storage directions above.