Winter lithium storage

[Paulz]

I’m confused on correct extreme cold winter storage of my 2017 Zion srt. 2 eco trek lithium batteries , one agm , and agm starting battery. It will be stored in unheated garage with -30 temps . I understand the winterization of van but not the electrical.
Thank you

[Davydd]

Originally Posted by Paulz

I’m confused on correct extreme cold winter storage of my 2017 Zion srt. 2 eco trek lithium batteries , one agm , and agm starting battery. It will be stored in unheated garage with -30 temps . I understand the winterization of van but not the electrical.
Thank you

Are you quoting Celsius or Fahrenheit at -30? Regardless -30C is -22F. Lithium Ion Phosphate batteries if their internal core temperature goes below -4F (-20C) the batteries will be permanently damaged. I'm not clear if incremental or absolute. This is what I got from the company that distributes my batteries, Elite Power Solutions.

"Temperatures below -4°F (-20°C) will cause the electrolyte to freeze which will cause permanent damage to the batteries if it does not kill them entirely. If storage temperatures will go below -4°F then you will need to heat the batteries to above -4°F to prevent damage to the battery. There is no exception to this."

As I mentioned batteries in use or being charged I have observed to be 10-15 degrees F. or so above the ambient air temperature. Also my unheated former garage that I could not store my van in always was almost 20F above ambient temperature. So you may have dodged a bullet if your core cells of your batteries have not gone below -4F or maybe your batteries have been incrementally damaged as in life of the battery or maybe your storage space has not gone down below -4F long enough to lower the battery temperature by the factors mentioned.

Electrical is a method of applying heat to keep the batteries above -4F (-20C) either directly with heating pads or indirectly by heated space. The latter can be by any fuel source. Directly by heating pads can be from the batteries themselves as long as you have a shore power connection of 15a.

Early on the Class B manufacturers and battery companies were ignorantly marketing to Americans with the -20 temperature confusing Celsius with Fahrenheit saying or implying it was -20F. ARV was the first to correct that and I confirmed that directly as I mentioned above. I don't know if Roadtrek ever did.

[Paulz]

Hi davydd. Up here near Ottawa Canada -30 to -40 Celsius

[@Michael]

Originally Posted by Paulz

Hi davydd. Up here near Ottawa Canada -30 to -40 Celsius

Does your campervan have built-in battery warmers? They will help.

I would certainly figure out how to put some heat into the van whenever it's below 0F/-20F in your garage. In my experience, one 1500 watt electric heater running continuously will warm my campvervan about 30F above outside temp, two heaters about 60F above outside temp.

[Winston]

Originally Posted by @Michael

In my experience, one 1500 watt electric heater running continuously will warm my campvervan about 30F above outside temp, two heaters about 60F above outside temp.

Wow, hate to see your utility bill!

We park 'inside', but our 'economical' fall-back plan is to heat the battery compartment only.

[Davydd]

Originally Posted by @Michael

Does your campervan have built-in battery warmers? They will help.

I would certainly figure out how to put some heat into the van whenever it's below 0F/-20F in your garage. In my experience, one 1500 watt electric heater running continuously will warm my campvervan about 30F above outside temp, two heaters about 60F above outside temp.

We have 16 3.4v 200ah cells assembled 4 in series for a nom. 12v 200ah battery as you see in the photo. Then we have 2 5amp electric resistant heating pads shown placed between two batteries (total of 4 for 800ah) and then encased in a fiber glass below the floor. So, 10 amps total that are on intermittently thermostatically controlled. They are powered off the batteries themselves. They will keep the batteries above 41F when it is -20F outside. If they ran continuously, which the don't, they would consume 240a in a 24 hour day. On the road with an 800ah battery bank that is no problem as we would certainly be driving every day to get to warm weather. In storage outside as we did the first two winters, it was no problem as the shore power kept the batteries charged.

[@Michael]

Originally Posted by Winston

Wow, hate to see your utility bill!

Electricity is a flat 9 cents/kwh in winter here, and I only run electric heat the few nights when it's below 0f.