As the cold approaches, it is important to consider how you store your battery. Proper winter storage helps the battery last longer, perform better, and reduces the risk of unpleasant surprises when the season starts again. Here are our best tips – and what applies to lithium, AGM, and GEL.
1. Fully charge the battery before storage
A battery stored discharged risks damage. Therefore, always make sure to give it a proper charge before winter storage.
- Lithium (LiFePO₄): Should not be fully charged. Charge to about 50–70 % and put away.
- AGM: Must always be fully charged to avoid sulfation.
- GEL: Same as AGM – store fully charged, but avoid overcharging.
2. Disconnect the battery from the vehicle
If the battery remains connected, small power leaks risk draining it over time. Disconnect the battery completely and store it separately.
- Lithium: This is especially important here because built-in electronics (BMS) can draw some power. Always disconnect if you are not using the vehicle.
- AGM & GEL: Also important – even small leakage currents can damage the battery when it stands for a long time.
3. Store cool but frost-free
Batteries do best in a cool, dry, and frost-free environment. Too warm dries out lead batteries and too cold can damage lithium during charging.
- Lithium: Can be stored cold, but never charged below 0 °C.
- AGM & GEL: Should also not be kept in cold below 0 °C. Frost-free and cool is optimal.
4. Maintenance charge during winter
All batteries benefit from being checked from time to time. A smart charger with a maintenance function makes it easy.
- Lithium: Does not need maintenance charging as often, but check the voltage occasionally. If it drops below about 12.5 V (for 12 V systems) → top it up a bit.
- AGM & GEL: Requires regular maintenance charging to stay healthy. For example, Victron Blue Smart IP65 is perfect – they charge automatically, are portable, and can stay connected all winter.
5. Check before the season starts
When spring approaches – charge the battery and check that it holds the correct voltage before reinstalling it.
- Lithium: Charge up to 100% and check via BMS or SmartShunt.
- AGM & GEL: Charge fully and check with a multimeter or via the Victron app if you have a smart charger from Victron.
Summary
- Lithium: Store at about 50–70%, frost-free, do not charge below 0 °C.
- AGM: Always store fully charged and maintain regular topping up.
- GEL: Same as AGM, but extra sensitive to overcharging → use a smart charger.
With the right routines, you avoid problems in the spring and extend the lifespan of your battery.
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