A lot of people have heard that lithium batteries shouldn’t be fully charged all the time. That’s partly true—for NMC batteries, keeping the charge under 90% is ideal. But LiFePO₄ batteries are different.

Let’s break down why it’s important to fully charge a LiFePO₄ battery from time to time.

1. Fixing the Battery Gauge and Keeping the Cells in Sync

LiFePO₄ batteries are made up of dozens (or even hundreds) of individual battery cells. Over time, those cells can fall out of balance—some may hold more power than others.

If you never fully charge the battery, the battery management system (BMS) can’t balance the cells properly. That leads to:

• Inaccurate battery level readings
• Reduced performance from the entire battery pack

Fully charging the battery helps reset the battery gauge and keeps all the cells working in sync.

2. Keeping the Battery Active and Healthy

When a LiFePO₄ battery is only partially charged for long periods, some of the active material inside can become inactive. That means the battery starts losing capacity faster.

A full charge helps reactivate those sleeping parts and keeps the battery’s chemistry healthy. It slows down aging and helps the battery last longer.

3. Preventing Battery Polarization

Polarization is a chemical issue that happens when the battery doesn’t get charged fully for a long time. It causes:

• Higher internal resistance
• Lower available capacity

Regular full charging helps prevent or reduce polarization, keeping the battery efficient and strong.

Best Charging Practices for LiFePO₄ Batteries

Here are some simple tips to charge your battery the right way:

1. Charge Before It Gets Too Low: Try to charge when the battery hits around 30–40%. In summer, let the battery cool down for 30 minutes before charging.
2. Always Use the Original Charger: Use the charger that came with your battery. It’s designed to deliver the correct voltage and current. Don’t risk using random chargers.
3. Fully Charge Once a Week: Even if you normally do shallow charging, it’s a good idea to do a slow full charge at least once a week. This helps balance the cells, keep the battery active, and extend its overall life.
4. Watch the Temperature: In winter, don’t charge the battery if it’s below 32°F (0°C). Bring it indoors or to a warm place first. In summer, don’t charge in places hotter than 104°F (40°C). A cool, shady spot is best.
5. Don’t Let It Sit Empty: If the battery won’t be used for a while, store it with at least a 50% charge. Add a top-up charge every month to keep it healthy.

Summary: Full Charging = Better Battery Health

If you rarely fully charge your LiFePO₄ battery, here’s what can go wrong:

• Cell imbalance
• Wrong battery level readings
• Faster capacity loss
• Higher resistance and worse performance

But with regular full charges—once a week is enough—you can keep the battery balanced, healthy, and long-lasting.