What you need to know about charging RC car batteries
Remote control car batteries need a charger made for that specific battery type — you cannot use a phone charger or a standard battery charger. The three most common types are NiMH (nickel-metal hydride), LiPo (lithium polymer), and NiCd (nickel-cadmium, older models). Each type requires different charging voltage and method, and using the wrong charger can damage the battery or create a fire risk.
The charger that came with your RC car is built for that battery. If you have lost it or want a second charger, you need to match the battery type and voltage — both printed on the battery itself or in your car's manual. Charging time ranges from 30 minutes to several hours depending on battery size and charger speed.
Key Takeaways
- NiMH batteries use a standard charger and can tolerate overcharging slightly, while LiPo batteries need a dedicated LiPo charger and will catch fire if overcharged.
- The battery label shows the type and voltage (measured in volts), which you must match when buying a replacement charger.
- Charging time depends on charger amperage: a 1-amp charger takes longer than a 2-amp charger for the same battery.
- LiPo batteries should be charged in a fireproof bag or container and never left unattended during charging.
- Most RC car chargers plug into a wall outlet, though some hobby-grade chargers can run on 12-volt DC power from a car battery.
NiMH batteries and standard chargers
NiMH batteries are the most forgiving type and come in most entry-level RC cars. They are labeled with a voltage like 7.2V or 9.6V and a capacity in milliamp-hours (mAh) — for example, 2000 mAh. A standard NiMH charger has a straightforward plug connection and a light that turns green when charging is done.
These chargers are inexpensive and widely available at toy stores and online retailers. They can tolerate being left plugged in after the battery is full, though doing so repeatedly shortens battery life. Charging time is usually two to four hours for a typical battery.
LiPo batteries and dedicated LiPo chargers
LiPo batteries are lighter and hold more power than NiMH, so they are common in faster or more expensive RC cars. They are also more dangerous: overcharging even slightly can cause the battery to swell, catch fire, or explode. This is why LiPo batteries require a dedicated LiPo charger that monitors each cell individually and stops charging at exactly the right moment.
A LiPo battery label shows the voltage as a number followed by "S" — for example, 3S means three cells, or 11.1 volts. The charger must be set to match this cell count. LiPo chargers cost more than NiMH chargers but are essential for safety. Never charge a LiPo battery unattended, and always charge it in a fireproof container or LiPo charging bag, which you can buy at any hobby shop.
Charging time for LiPo batteries is typically 30 minutes to two hours, depending on the charger's amperage setting. A higher amperage charges faster but generates more heat, so many people use a slower setting to extend battery life.
Finding the right charger for your battery
The first step is to read the label on your battery. It will show the battery type (NiMH, LiPo, or NiCd), the voltage, and the capacity in mAh. Write down all three pieces of information.
If you have the original charger, check whether it is still working by plugging it in and connecting the battery. The charger should show a light or display. If the charger is broken or lost, search online for "[battery type] [voltage] charger" — for example, "NiMH 7.2V charger" or "3S LiPo charger." Hobby retailers like Horizon Hobby, Tower Hobbies, and local hobby shops stock chargers for common RC car batteries.
When buying a replacement, confirm that the charger accepts the voltage you need. Some chargers are adjustable and work with multiple voltages, which is useful if you own several RC cars. The charger's amperage (measured in amps) determines charging speed; a 1-amp charger is slower but gentler on the battery, while a 2-amp or 3-amp charger is faster.
Charging steps for NiMH batteries
Plug the charger into a wall outlet. Connect the battery to the charger using the connector on the battery — it will only fit one way. The charger light will turn red or show "charging." Leave the battery connected until the light turns green, which signals that charging is complete.
Do not leave the battery connected for more than an hour after the light turns green, as this can damage it over time. Unplug the charger from the wall and disconnect the battery. Your battery is now ready to use.
Charging steps for LiPo batteries
Place the LiPo battery inside a fireproof charging bag or container. Plug the charger into a wall outlet. Set the charger to the correct cell count — check the battery label for the "S" number. Connect the battery to the charger using the balance connector (a small multi-pin plug) and the main power connector.
The charger display will show the voltage of each cell and the charging progress. Stay in the room while charging. When the display shows that charging is complete, unplug the charger from the wall, disconnect the battery, and remove it from the charging bag. Never leave a LiPo battery charging unattended, and never charge it indoors near flammable materials.
Chargers that run on 12-volt DC power
Some hobby-grade chargers can be powered by a 12-volt car battery or a dedicated power supply instead of a wall outlet. These are useful if you charge RC cars at the track or field. The charger connects to the 12-volt source using a cigarette-lighter plug or bare wires, and then the RC battery connects to the charger the same way as with a wall-powered charger.
These chargers are more expensive than wall-powered models but allow you to charge multiple batteries quickly without needing an outlet. They are common among competitive RC hobbyists.
Frequently Asked Questions
Can I use a phone charger or laptop charger on my RC battery?
No. Phone and laptop chargers output different voltage and current than RC batteries need, and using one will damage the battery or the charger. Always use a charger designed for the specific battery type and voltage.
How do I know when my LiPo battery is fully charged?
A LiPo charger displays the voltage of each cell on its screen. When all cells reach 4.2 volts, the battery is full. Most chargers beep or show a message when charging is complete. Do not charge beyond this point.
Why did my LiPo battery swell up?
Swelling means the battery was overcharged or damaged internally. Stop using it when ready and dispose of it at an electronics recycling center. Do not try to charge it again or use it in your RC car, as it can catch fire.
Can I charge my RC battery overnight?
NiMH batteries can tolerate overnight charging but will degrade faster over time. LiPo batteries should never be left charging unattended — charge them only when you are in the room and can monitor them. Set a timer to remind yourself when charging should be complete.
What is the difference between a 1-amp and 2-amp charger?
A 2-amp charger delivers twice the current, so it charges the battery in roughly half the time. However, faster charging generates more heat and can shorten battery life. For casual use, a 1-amp charger is gentler; for frequent charging, a 2-amp charger saves time.