To fully charge a 12V LiFePO4 battery, you need a charger with a voltage range between 14V and 14.6V. Using a charger with a lower voltage will still charge the battery, but it won’t allow it to reach 100% capacity.

Trickle charging is unsuitable for lithium batteries. Charging a LiFePO4 battery with a trickle charger not designed for this battery type can result in overcharging or damage, as lithium batteries have different charging requirements compared to traditional lead-acid batteries.

Charging a battery to less than 100% and avoiding complete discharge consistently enhances cell longevity. Likewise, operating lithium batteries within a 20%-80% state of charge (SoC) significantly extends their lifespan. For instance, Power Queen deep cycle lithium batteries can endure over 4,000 deep cycles at 100% Depth of Discharge (DoD), exceed 6,000 cycles at 80% DoD, and surpass 15,000 cycles at 60% DoD.

Leaving a lithium-ion battery on the charger overnight is generally safe if you’re using a charger like Power Queen’s, which automatically stops charging once the battery reaches full capacity. Most modern lithium-ion chargers have this feature to prevent overcharging.

It's crucial to ensure your charger provides the appropriate current and voltage for the LiFePO4 lithium battery you’re charging. For instance, using a 24V charger on a 12V LiFePO4 battery is not recommended. It's also important to use a charger specifically designed for the battery's chemistry. Furthermore, if you're using a standard lead-acid charger for a LiFePO4 battery, ensure it lacks features like desulfation or dead battery mode, as these can harm the LiFePO4 battery.