Winterizing solar/batteries - sporadic cold-weather use

Life on the Road Electrical: Batteries, Generators, Solar, etc...
1

Hi!

I’m hoping for some knowledgeable folks to weigh in on how best to manage the electrical system in a van that lives in cold weather during the winters.

The set up is a couple solar panels on the roof, a pair of Lithium batteries inside the van, some direct current draws (lights, fan, water pump) and an inverter for outlets etc (fridge, water heater). There is no alternator charging of the batteries.

I don’t have a heater in the van, and the van cools to ambient temps (read: cold!) for extended duration when sitting throughout the winter.

My understanding is that the Lithium batteries are fine to discharge in cold weather, but are not designed to be charged in cold temps. To avoid discharging, I killed all the connections to any loads (so now cabin lights don’t work, etc - it’s basically just a vehicle with inactive stuff in it). To avoid cold weather charging, I disconnected the solar panels. Is this a good approach? Am I fine to leave the batteries in the vehicle in the cold isolated from charge/discharge over the winter? Should I run a trickle charger to them? Should I bring them inside?

Other questions… apparently disconnected solar panels can end up damaging themselves if they generate charge with nowhere to send it… Any solutions here? Typically winters here are fairly gray, and if the panels are covered in snow for portions of it, they wouldn’t be seeing too much power generating opportunities. But this feels like I am just hoping and not really preparing.

Another scenario is that I want to drive the van somewhere warm for a week and want to have everything connected again - I assume I would want to warm up the batteries (run the van for a while to heat up the interior) before reconnecting solar or plugging into shore power?

And shucks, while rambling on about it, another thought is the hope to install a system to charge the house batteries off the vehicle battery while driving (I’ll have to research options). If I had this installed, would I also need to be mindful in cold temps of starting the vehicle and it charging the house batteries in cold weather? I would have to wait until the house has warmed the batteries up enough to then start to charge them?

A lot of questions and learning to be had. Thanks for any advice!

2

I can’t answer most of your questions. I found mixed results on the Internet when I looked to see whether leaving solar cells disconnected could cause damage. But to be sure, perhaps you could cover them?

By the way, some sources say “lithium ion batteries”, especially certain lithium ion chemistries, are more resistant to cold weather damage than non-ionic lithium batteries.

But even ordinary lead acid batteries can also be damaged if they become cold enough to freeze the electrolyte. So if you happen to have a somewhat garage, your van may have fewer battery problems if you keep the van there as often as possible.

If it were me, I would take the batteries not needed to run the vehicle indoors during cold weather. Or if possible, you could choose to live in warmer climates during the winter.

3

Get a self heating battery with BMS, that will heat itself before being charged on the road and has bms protection against cold charging.
Lithium house batteries in RVs get stored in the North all the time, as soon as they aren’t low are fine. Sure its even better to take it out if you are storing for a few months, but it can get old if you use it on and off

4

I have 270 watts of solar panels on my boat. During the winter months, boat is at the dock. Solar panels are turned off. One panel is over twenty years old. Newer 100 flexible panel is deteriorating from the sun. My van has two 100 watt panels on the roof. They are also off during the winter.
All my batteries have some kind of battery maintainer connected to them. None are Lithium.