Lithium batteries and solar panel winterizing

[richling]

Hi all,

I'll be getting our brand new 21NE next week. Just in time for me to put it in storage for Michigan winter. Our trailer has the 2 solar panels and 2 lithium batteries.

Here is the winterizing process from GoPower:

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:

*

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

*

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.



Is this what most folks do with the same climate and batteries/solar options?

[JeffreyG]

That sounds like a heck of a lot of work, and I'm not planning to do all of that at all. I've read the 'storage' requirements from every LiFePO4 manufacturer, and while they all suggest putting the batteries indoors in the winter, it seems like the only real reason they suggest doing so is in case the ABS case cracks in extreme cold. It almost never get's that cold here, and I guess if it was going to I could go pull the batteries out.

I have access to some real battery experts, and they all see no real reason to store batteries indoors over a Michigan winter in terms of cell life and performance.

So here is my plan:
1) The trailer will be covered with a high quality (and thick) cover, so the solar panels will be covered in any case.
2) I'll charge the battery to 80% before storage.
3) I have breakers installed on the line from solar panels to controller, and from solar controller to battery. I'll open both breakers.
4) Pull the main negative battery cable off the shunt, which will isolate the battery negative from all possible loads / charges.
5) Put a tub of Damp-Rid in the trailer. Check on everything now and then.

[richling]

Hi Jeff! A fellow escape owner close by! I live in Warren.

I agree on your thoughts. I've had some communications with Battleborn and they suggest what you say. I'm thinking the same as you. I will cover the solar panels and disconnect the batteries like you said.

The formal response from GoPower seems to be somewhat overkill as these trailers with the full 3 seasons package are able to be used in temperatures well below freezing.

[gbaglo]

Storing lithium batteries off the floor sounds like the myth that batteries shouldn't be stored on concrete lives on. That used to be, before plastic cases.

[MyronL]

This will be my Battleborn's third winter outside in upper New Mexico (elevation 6700 ft.) untouched in the tongue box. Not worried about it.

[richm]

Originally Posted by richling

• 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.
...
• Unhook your solar panels from your solar controller

Why would one need to block light on solar panels when they are disconnected?

[gbaglo]

Originally Posted by richm

Why would one need to block light on solar panels when they are disconnected?

You cover them before disconnecting them.

[alanmalk]

Originally Posted by gbaglo

You cover them before disconnecting them.

Alternatively, disconnect the solar after sunset. Shouldn't be a hardship since there seems to be more night time than daylight this time of year. If the panel(s) are still exposed to daylight then a couple of wire nuts on disconnected wires will prevent the accidental short circuit.

Bring the batteries inside if the low temperature is going to fall below the storage temperature specified by the manufacture (mine say -20F, which has been hit occasionally in the Denver area.)

One has to wonder how long the myth of keeping batteries off the floor is going to hang around? I've kept my trolling motor on my concrete garage floor for 10 years, and the floor is still in perfect condition.

[Centex]

Originally Posted by alanmalk

... One has to wonder how long the myth of keeping batteries off the floor is going to hang around? I've kept my trolling motor on my concrete garage floor for 10 years, and the floor is still in perfect condition.

[richm]

Originally Posted by gbaglo

You cover them before disconnecting them.

The connections are not likely to arc upon disconnect, so I'm not sure why this is necessary.

[richm]

Battleborne batteries have a "battery management system" that features "low temperature charge protection". This typically blocks the battery from charging below around 40deg F.

The reason I point this out is, manual methods may not be 100% reliable to always protect from, for example, a sudden overnight drop or cold front. And charging below freezing will permanently damage a lithium battery. You lose Amp Hours each time this happens.

"low temperature charge protection" may be more important than disconnecting the solar panels for that reason. And if you have it, you don't need to disconnect panels.

[richling]

That's a good question! GoPower should answer that! ��

[JeffreyG]

Originally Posted by richm

Why would one need to block light on solar panels when they are disconnected?

I'm guessing they are picturing panels sitting at 22V open voltage, and clumsy you allows the bare wire ends to come into contact with each other.

Otherwise I can't imaging why they need to be covered, other than also keeping them from accumulating a layer of grime all winter.

[richling]

I agree Jeff, they are protecting themselves from potential litigation.

[Vermilye]

Originally Posted by richm

Why would one need to block light on solar panels when they are disconnected?

The suggestion is to cover the panels BEFORE disconnecting them from the controller.

Your don't really need to, but there is a bit of a shock hazard and possible sparking if the panels are active when you disconnect them from the input to the controller. If you don't have a disconnect between the solar panels & the controller, it is important to cover the panels (or disconnect them) before disconnecting the controller from the batteries.

I suspect it is the lawyers that are pushing covering the panel before disconnecting. On a larger system, it would definitely be wise; the voltages & currents could be much higher.

[richm]

Originally Posted by Vermilye

Your don't really need to, but there is a bit of a shock hazard and possible sparking if the panels are active when you disconnect them from the input to the controller.

At the instant the panels are disconnected from the controller, the panels and controller are at equal voltage, so there's no risk of spark.

I think it's awesome that you guys are emphasizing safety and diving into the design, but I suggest you get better advice, because, yes, the go power recommendations seem to be leading you off track "into the weeds." Don't take my word for it. Maybe get advice from Victron or Battleborne about winterizing and safety. At the very least, they have features that solve these issues.

[yardsale]

We leave ours outdoors all winter ever since we bought our 17B.. Shovel snow off the solar panel once in a while. Lead acid batteries,

[Brian B-P]

Originally Posted by richm

Why would one need to block light on solar panels when they are disconnected?

You don't.

Originally Posted by gbaglo

You cover them before disconnecting them.

Or you don't cover them; it doesn't matter. Covering is for installations without disconnects between the panels and the controller.

Originally Posted by richm

The connections are not likely to arc upon disconnect, so I'm not sure why this is necessary.

I agree - it's not necessary.

Originally Posted by JeffreyG

I'm guessing they are picturing panels sitting at 22V open voltage, and clumsy you allows the bare wire ends to come into contact with each other.

Otherwise I can't imaging why they need to be covered, other than also keeping them from accumulating a layer of grime all winter.

Panels can be shorted without harm; indeed, "short circuit current" is a standard specification.

Covering is for installations without disconnects, or for physical protection of the unused panels during storage.

Originally Posted by Vermilye

The suggestion is to cover the panels BEFORE disconnecting them from the controller.

Your don't really need to, but there is a bit of a shock hazard and possible sparking if the panels are active when you disconnect them from the input to the controller. If you don't have a disconnect between the solar panels & the controller, it is important to cover the panels (or disconnect them) before disconnecting the controller from the batteries.

I suspect it is the lawyers that are pushing covering the panel before disconnecting. On a larger system, it would definitely be wise; the voltages & currents could be much higher.

I agree. The advice is nonsense for a travel trailer and its low-voltage array only capable of delivering a few amps.

Originally Posted by richm

... I think it's awesome that you guys are emphasizing safety and diving into the design, but I suggest you get better advice, because, yes, the go power recommendations seem to be leading you off track "into the weeds." Don't take my word for it. Maybe get advice from Victron or Battleborne about winterizing and safety. At the very least, they have features that solve these issues.

I agree that the "cover and disconnect panels" recommendation is a distraction from anything important. On the other hand, I don't think I would bother asking BattleBorn anything about solar systems.

[richling]

All great discussions! I asked this question directly to Escape on their website forum. They directed me to GoPower (Dometic)for the winterizing of the solar system. A little 'pass the buck' activity. I know that there's been references on this thread to Battleborn, but the batterries from Escapes full solar package option are GoPower. Lifepo4-100ah

[JeffreyG]

Originally Posted by richling

All great discussions! I asked this question directly to Escape on their website forum. They directed me to GoPower (Dometic)for the winterizing of the solar system. A little 'pass the buck' activity. I know that there's been references on this thread to Battleborn, but the batterries from Escapes full solar package option are GoPower. Lifepo4-100ah

Battleborn says to charge to 100%, then disconnect and store all winter, checking / charging every three months.

Go-Power says to charge to something like 80% and then do the same.

They both suggest pulling and storing the batteries indoors, but only to prevent the ABS from cracking in extremely low temperatures. I've concluded this is probably not necessary in my climate, where 0F is a very cold day.

So.....that's about it. IMO, all you really need to do is charge them up, pull the negative battery cable, and disconnect the solar panels from the controller (which should have a breaker or shutoff).