An Off-Grid Cabin in Sweden – 8 Months of Real LiFePO4 Winter Use

When my old AGM battery failed last winter, I realized it was time to rethink my entire off-grid power system. Replacing it with another AGM battery would have been the safe choice, but curiosity – and a lot of calculations – led me down a different path.

Eight months later, after real-world use including winter visits in temperatures well below freezing, I can confidently say that switching to LiFePO4 was the right decision.

Background – From AGM to LiFePO4

The cabin is completely off-grid and has had solar panels since the early 1990s. When we took over, a solar system from 1994 was still mounted on the roof, originally purchased from a Clas Ohlson catalog that was still lying around in the cabin.

Over the years, I have gradually upgraded the system:

• new solar panels
• a Victron charge controller
• a Victron inverter

Until recently, everything was powered by a 240Ah AGM battery, which worked well for lighting and a robotic lawn mower during summer. When that battery finally failed, I needed to find a replacement.

Out of pure curiosity, I discussed the options with ChatGPT. Its recommendation was clear: LiFePO4 batteries. At first, I was very skeptical – especially because LiFePO4 batteries should not be charged below freezing. However, after running several usage calculations, it became clear that since we visit the cabin only a few times during winter and do not charge the battery then, the advantages outweighed the drawbacks.

Choosing Redodo and Rebuilding the Off-Grid System

After researching different brands, I came across Redodo. Their batteries were in the right price range and had solid reviews. I chose the:

• Redodo 12V 280Ah Low-Temp LiFePO4 Battery
• Built-in BMS with low-temperature protection

Redodo 12V 280Ah LiFePO4 Lithium Low-Temp Battery

• 3584Wh Energy & 4000+ Long Cycles
• Upgraded 200A BMS with Cold-Weather Protection

Learn More

To better understand and document real-world usage, I also added an external battery monitor to track state of charge, voltage, and energy consumption over time.

At the same time, I rebuilt parts of the electrical system. During this process, I was in contact with Redodo’s technical support, who helped review my wiring diagram. Their responsiveness and technical competence were very reassuring.

Technical Overview of the System

System voltage: 12V off-grid

Battery: Redodo 12V 280Ah LiFePO4

Battery monitoring: External battery monitor (SOC, voltage, Ah)

Solar panels:

• JKM2700PP panels
• Connected in parallel for improved shading tolerance and stable system voltage

Charge controller:

• Victron SmartSolar MPPT 100/20
• Configured specifically for LiFePO4 batteries

Inverter:

• Victron pure sine wave inverter
• Used to power:
• TV
• Internet router
• Chargers
• Robotic lawn mower during summer

8 Months of Experience – Including Winter Use

The system was commissioned in spring. Until December 30, the battery remained fully charged without any issues.

Winter visit #1 – Late December

• Sub-zero temperatures
• Approx. 20% battery usage
• No performance issues at all

Winter visit #2 – February 4

• Temperature: –14°C
• One overnight stay
• Remote work + TV usage
• Approx.16% battery usage

Once the cabin was heated and the sun was up, the battery even accepted some charging during the day. In winter, the main limitation has been solar input – not the battery itself.

My initial concern about winter operation turned out to be unfounded. In practice, the battery capacity has been more than sufficient for our needs.

Weight and Handling – An Overlooked Advantage

One of the most underestimated benefits is weight. Carrying a 280Ah LiFePO4 battery to an off-grid cabin is dramatically easier than transporting an AGM battery with comparable usable capacity. For remote locations where everything must be carried or transported manually, this is a major advantage.

Summary

After eight months of real-world use, including winter conditions, I can confidently say:

• LiFePO4 works extremely well in cold climates when used correctly
• The battery capacity easily covers sporadic winter visits
• Weight savings make a huge practical difference
• System stability and predictability are excellent
• Redodo’s technical support added significant value during installation

For my use case, the benefits clearly outweigh the limitations.

What’s Next

The next steps for the system include:

• Adding a generator-powered battery charger to allow charging once the cabin is heated during winter
• Exploring the possibility of installing a diesel heater, now that sufficient electrical capacity is available
• Continuing to document long-term performance over multiple seasons

What started as a simple battery replacement has turned into a much more capable and flexible off-grid power system than I originally planned.

Explore more Redodo’s LiFePO4 off-grid solar batteries and low-temp lithium batteries for cold weather.

Read More:

Why I Switched from Lead-Acid Batteries to Lithium Iron Phosphate

Redodo Powers Our Family Camping — All Year Long

How I Power My Cabin with Redodo Solar Batteries?