Choosing the Right LiPo Battery Charger
Choosing the right charger depends on the batteries you use, how quickly you want to charge them and whether you need to charge one or several packs at once. The key specifications to check are supported battery chemistry, cell count, maximum charge current, charger wattage, number of channels and whether the charger includes its own AC power supply.
A compact charger may be ideal for small FPV packs, while larger 6S batteries and commercial UAV batteries can require substantially more charging power. Always make sure the charger supports the battery chemistry and cell count you intend to use.
AC vs DC LiPo Chargers
An AC charger can plug directly into a standard mains outlet because the power supply is built into the charger. This makes AC chargers convenient for home, workshop and travel use.
A DC charger requires a separate DC power source. The advantage is that DC chargers can often deliver considerably more charging power than similarly sized AC units.
Some chargers support both AC and DC input, providing convenient mains charging while allowing higher output when connected to a suitable external power supply.
When comparing chargers, check both the AC and DC output specifications because the maximum available charging power can differ depending on the input source.
Understanding Charger Wattage
Charger wattage determines how much electrical power the charger can deliver to the battery.
A charger may advertise a high maximum current, but it can only provide that current when enough wattage is available. As battery voltage increases, more power is required to maintain the same charging current.
For example, a 6S LiPo reaches approximately 25.2V when fully charged. Charging a 5000mAh 6S battery at 5A requires roughly 126W before allowing for charger losses.
This is why higher-voltage and larger-capacity batteries benefit from more powerful chargers. A low-powered charger may still charge them safely, but it may not be able to achieve the desired charge rate.
What Does 1C Charging Mean?
Battery charge rate is often expressed as a C rating. A common charging rate for many LiPo batteries is 1C, although you should always follow the battery manufacturer’s specified maximum charge rate.
To calculate a 1C charge current, convert the battery capacity from milliamp hours to amp hours.
For example:
A 1500mAh battery has a capacity of 1.5Ah.
At 1C, the charge current is 1.5A.
A 5000mAh battery has a capacity of 5Ah, so a 1C charge rate would be 5A.
Some batteries are rated to accept higher charging rates, but faster charging increases the demands placed on the battery and charging system. Do not assume a battery can safely be charged above 1C unless the manufacturer specifies that it can.
Balance Charging LiPo Batteries
Multi-cell LiPo batteries contain several cells connected in series. During charging, those individual cells need to remain at similar voltages.
A balance charger monitors the individual cells through the battery’s balance connector and adjusts the charging process to keep the cells balanced.
Balance charging is particularly important for maintaining battery performance and detecting abnormal differences between cells. Use the correct battery chemistry and cell-count setting, and always connect the balance lead as required by the charger manufacturer.
Single, Dual and Multi-Channel Chargers
A single-channel charger charges one battery at a time and can be a good choice for pilots who only need to charge a small number of packs.
Dual-channel and multi-channel chargers allow multiple batteries to be charged independently. This can be particularly useful for FPV pilots who use several packs during a flying session.
When comparing multi-channel chargers, check whether the advertised wattage applies per channel or across the entire charger. Some chargers divide their available power between channels when several batteries are being charged simultaneously.
Chargers for 1S and 2S FPV Batteries
Small FPV drones and whoops commonly use 1S or 2S batteries and often benefit from dedicated multi-port chargers.
Chargers designed specifically for these batteries can charge several small packs individually and may also provide storage-charge functions. Products such as compact whoop chargers are more practical for large numbers of small batteries than using a conventional high-power charger with adapters.
Make sure the charger supports the connector used by your batteries, such as BT2.0 or other micro battery connectors.
Charging 4S and 6S FPV Batteries
4S and 6S batteries are widely used in FPV racing and freestyle builds. For these packs, consider both charger current and available wattage.
Higher-capacity 6S batteries can quickly exceed the capabilities of a small charger if you want to charge at around 1C. A more powerful charger can reduce charge times and provide additional capacity if you later move to larger batteries.
Always check the charger’s maximum supported cell count as well as its power rating.
Charging Large and Commercial UAV Batteries
Commercial UAV batteries can have significantly greater capacity than conventional FPV packs. High-capacity 6S, 12S and other large battery systems may require hundreds of watts of charging power.
For these applications, charger wattage, maximum current, input power supply and connector compatibility become especially important. A powerful DC charger may also require a suitably rated external power supply to achieve its advertised output.
Always use charging equipment appropriate for the battery manufacturer’s specifications and intended UAV platform.
Storage Charging and Battery Maintenance
LiPo batteries that will not be used for an extended period should generally be stored at an appropriate storage voltage rather than left fully charged.
Many modern chargers include a dedicated storage mode that charges or discharges the battery towards the appropriate storage voltage.
Some chargers also include discharge functions, battery resistance measurements and cell-voltage monitoring that can help assess battery condition over time.
LiPo Charger FAQs
What size charger do I need?
Choose a charger that supports your battery chemistry and cell count, then calculate how much charging power you need based on battery voltage, capacity and desired charge rate. Larger batteries and faster charging require more wattage.
What is the difference between an AC and DC charger?
AC chargers contain a mains power supply and can plug directly into a wall outlet. DC chargers require an external power source but can often provide significantly higher output.
What charge rate should I use for a LiPo battery?
Always follow the battery manufacturer’s specification. Where 1C charging is recommended, a 1500mAh battery would charge at 1.5A and a 5000mAh battery at 5A.
Why is balance charging important?
Balance charging monitors the voltage of each cell in a multi-cell battery and helps keep the cells at similar voltage levels during charging.
