How to safely store and charge LiPo batteries at home

You have just landed, and the battery is warm in your hand. Should you charge it straight away? Not yet. A few calm habits between landing and storage make your LiPo (lithium polymer) battery much easier to look after. If you are still preparing your first build, keep this first drone setup guide open too.

Why do LiPo batteries need a routine?

LiPo batteries pack a lot of energy into a small, light body, which is why drones use them. Poor charging, heat and physical damage can all harm them. A routine works like a pilot’s checklist: you do the same steps every time, so you are less likely to miss one. It reduces risk, though it cannot remove it completely. The manufacturer’s instructions for your battery and charger always come first. Treat everything here as general guidance. So what should happen after you land?

How to charge a LiPo battery, step by step

Let it cool, then check it

Unplug the battery from the drone and let it reach room temperature before you charge it. Then look it over and check for:

• Swelling or a puffy shape
• Dents, punctures or a torn wrapper
• Damaged wires or connectors

Waiting for a warm battery? Keep practising in the free browser simulator, with no install and no battery needed. You can also read more about the free online drone simulator first.

Match the charger and settings to the battery

Use a charger made for LiPo batteries, then match these settings to the label on your pack:

1. Battery type: choose LiPo mode.
2. Cell count: a cell is one unit inside the pack, and a pack may have one or several. Set the exact number.
3. Charging mode: use balance charging on multi-cell packs. It keeps the cells at matching voltages, through a small extra plug called the balance lead.
4. Charge rate: about 1C is common practice unless the manufacturer says otherwise.

What does 1C mean? It is a charging current that matches the battery’s capacity, so a 1,000 mAh (milliamp-hours, the unit for capacity) battery would charge at 1 A (amp). If the manufacturer gives a different figure, use theirs. Single-cell batteries have no balance lead, so they need a charger made for them.

Choose a safe spot and stay nearby

Agree with a parent or another adult on where charging will happen. Pick a non-flammable surface, and keep anything that can burn well away from it. A LiPo-safe bag (a fire-resistant pouch made for these batteries) or non-flammable surface reduces risk, but it does not remove it. That is why you stay nearby: you can notice unusual heat, swelling or a burning smell early and act on it. Avoid overnight charging, and unplug the battery when it finishes.

Charging is only half the routine, though. What happens to a battery you will not fly for a while?

How to store a LiPo battery between flights

Keep it near storage voltage

A LiPo battery is generally happiest resting in the middle, not full or empty. Leaving it full for long periods can age it faster, while letting it sit too empty can damage the cells. Common hobby practice is to keep each cell at about 3.8 V. Think of it as a comfortable resting point for your battery. If your charger has a storage mode, use it. This mode charges or discharges the battery towards storage voltage, so you do not have to work it out by hand.

Pick a cool, dry place

Keep your batteries somewhere cool and dry. Avoid direct sun, hot vehicles and flammable materials, and keep them out of reach of young children. A routine also needs an exit. How do you know when a battery should not go back on the charger?

When should you stop using a battery?

Stop using a battery and do not charge it if you notice any of these signs:

• Swelling
• Punctures
• Damaged wires
• Unusual heat
• A burning smell

If it is hot, smoking or burning, keep away from it and do not touch it. Tell an adult straight away, then follow the manufacturer’s guidance.

Your quick LiPo checklist

Before charging

• Battery is at room temperature
• No swelling, punctures or damaged wires
• LiPo charger, correct cell count and suitable charge rate

While charging

• On a non-flammable surface, away from anything that can burn
• You are nearby
• Unplugged when finished

Before storing

• Each cell is at about 3.8 V, or the manufacturer’s figure
• Kept cool and dry, away from sun, hot vehicles and flammable materials
• Out of reach of young children

Stop signs

• Swelling, punctures, damaged wires, unusual heat or a burning smell mean you stop using it

Frequently asked questions

Keep flying while your battery rests

Your battery needs rest, but your flying practice does not have to stop. Try the free Aasma flight simulator at sim.aasmaaerospace.in. It runs in your browser, with 6 missions, keyboard controls and no install. When you are ready to build, explore Aasma’s drone learning kits. Now take another look at the label on your battery. What do those numbers and letters actually tell you?