Winter Care for Fogstar Lithium Leisure Batteries

Lithium iron phosphate (LiFePO4) batteries are reliable workhorses, but cold weather can complicate their charging routine. Discharging in sub‑zero conditions is fine; the trouble starts when you try to charge them at temperatures below freezing.

Many Fogstar models come with built-in heating pads, including Drift and PRO, which pre-warm the cells so you can charge safely even when the temperature drops. Drift ECO models skip the heating pads, but they’re still engineered to cope with colder conditions.

This guide walks you through how to look after Drift, PRO and ECO batteries through the winter months.

Charging in Low Temperatures

Drift and PRO (with built‑in heaters)

• Integrated heating pads: If internal temperatures drop below freezing, the battery’s 36‑watt heating pad warms the cells using the incoming charge. Charging will then only start once the cells are warm enough.

• Simple operation: You don’t need to add external heaters or insulation. Connect your charger as usual and let the battery’s management system handle the rest.

• Cold discharge: These packs will continue to deliver power even in icy conditions. The heaters are solely for safe charging.

ECO (no internal heater)

• Under‑temperature protection: The ECO battery’s management system blocks charging when the cells are below 0 °C. This protects the battery from any damage.

• Manual warming: If you need to charge in freezing weather, bring the battery indoors or use appropriate insulation to raise its temperature above about 5 °C before connecting a charger.

Long‑Term Storage and Isolation

Powering down your van or boat for the winter? If your battery will sit unused for weeks or months, follow these guidelines to preserve its health:

1. Store at mid‑charge: Aim for roughly 50% state of charge. Storing fully charged or fully discharged for extended periods accelerates wear. For batteries without Bluetooth (Drift ECO), aim for around 13.4V.

2. 

   Isolate the battery: Switch off both the charge and discharge in the App, use the ON/OFF buttons, and disconnect the battery entirely if possible. This prevents parasitic draw - small, constant power drains from connected devices (e.g. inverters, DC‑DC chargers, tracking/monitoring hardware, alarms, lighting controllers).

3. Periodic check: Every two or three months, verify the state of charge and top-up the charge if it has fallen below 30%. Keeping the charge in the middle range is best.

4. Before returning to use: When you’re ready to power-up again, perform a full charge and discharge cycle to recalibrate the battery management system.

5. Storage Environment: Although Fogstar ECO and Drift batteries are IP-rated and can handle damp or dusty environments, long-term storage still benefits from moderation. Avoid leaving them somewhere subject to freezing or extreme heat. A sheltered, stable spot; like a garage, is ideal.

Cold Weather and Slow Charging. What’s Normal?

Cold weather naturally slows lithium batteries. When temperatures drop, internal resistance rises, so chargers hit their voltage targets faster than normal. That can make your system jump to absorb early, cut absorb time short or slip straight into float. It isn’t a fault. It’s just the battery reacting to the cold. As winter bites, expect slower charging and unusual charge profiles, especially with unheated batteries.

Finally…

Fogstar’s Drift and PRO models simplify winter care by managing their own heating, while the ECO model requires a little more attention when charging in the cold. Regardless of the model, storing batteries partially charged, isolating them during long breaks, and keeping them in a moderate environment will help ensure they deliver reliable power year after year.