LifePo4 Northern MN Off Grid Seasonal Cabin Recommendations Needed

[torridone45]

I am currently building a 24VDC system for a seasonal off grid cabin in Northern MN. It does get extremely cold and there are times when I am snowed out and cannot get access. I use it mainly in the summer plus November during deer season and a few times during the winter for ice fishing etc. I had (4)x 6V crown batteries that just did not give enough output in the winter. I am looking at switching to 24VDC with heated LifePo4 batteries. If I have the ability to put the batteries in a pit under the frost line do I still need heated? I could put them in individual coolers with extra insulation etc. I looked at the Rich Solar Alpha 4 batteries, but they use battery power to run the heaters, and I am concerned that they will just self-drain during the winter. Any recommendations?

 

[SunDave]

I am currently building a 24VDC system for a seasonal off grid cabin in Northern MN. It does get extremely cold and there are times when I am snowed out and cannot get access. I use it mainly in the summer plus November during deer season and a few times during the winter for ice fishing etc. I had (4)x 6V crown batteries that just did not give enough output in the winter. I am looking at switching to 24VDC with heated LifePo4 batteries. If I have the ability to put the batteries in a pit under the frost line do I still need heated? I could put them in individual coolers with extra insulation etc. I looked at the Rich Solar Alpha 4 batteries, but they use battery power to run the heaters, and I am concerned that they will just self-drain during the winter. Any recommendations?

Burying batteries is an interesting idea indeed. Takes care of theft issues, and climate issues. Could be worth an experiment. Although, it would have to be very deep, and the top insulated or re-packed well, otherwise the frost will push through the newly loosened soil. Serviceability would suffer as well.

I have a cabin with some friends in the same climate zone, and run 24 volt as well. I recently replaced batteries and stuck with AGM because of the extreme cold and the inability for the solar there to get any meaningful charge after pre-heating the batteries.

Just one person's take, but I stuck with AGM, and made the 800 watts of solar adjustable to vertical so that I still get sun in the winter without clearing off the panels or baby-sitting the system. We run our system for lights, RV furnace fan, water pumps, and sometimes a mini-fridge or ice maker.

 

[torridone45]

Thank you for the reply SunDave. I would like to go with LifePo4 if possible due to weight and available amp hours. If it does not work, I will look at AGM as an alternate option. The price of LifePo4 batteries have come down such that I there is no longer a big difference when you account for actual available amp hours. Ideally, I would use (2)x 24V 100amphr or (2)x 12V200amphr batteries. I see LiTime now has heated batteries. Based on one of Will's videos I question if I need heaters if well insulated 5 feet down in a cellar/pit. If I don't need heaters, that opens up a lot of other brand options.

 

[SunDave]

Let me know if you do have luck with the cellar/pit option. Would be interested myself!

Also, this was just posted: https://diysolarforum.com/threads/s...ps-not-great-for-humidity.89793/#post-1192550

 

[wpns]

Self-heated batteries in small coolers or a decommissioned chest freezer should be well insulated enough to not need a lot of heating power. A vertical bifacial panel for maintenance power's a good idea too.

 

[torridone45]

Thanks, wpns. I may give that a try.