What size battery is needed for a 1000w motor?
2 Answers
A 1000w motor requires a 72V battery according to the 0.5C2 discharge rate rule. The working principle of the motor is that the direction of the force on the conductor is determined by the left-hand rule. This pair of electromagnetic forces forms a torque acting on the armature, which is called electromagnetic torque in rotating motors. The direction of the torque is counterclockwise, attempting to make the armature rotate counterclockwise. If this electromagnetic torque can overcome the resistance torque on the armature (such as the resistance torque caused by friction and other load torques), the armature can rotate counterclockwise. The excitation method of a DC motor refers to how the excitation winding is powered to generate excitation magnetomotive force and establish the main magnetic field. Car batteries, also known as storage batteries, are a type of battery. Their working principle is to convert chemical energy into electrical energy. Typically, the most commonly used battery is the lead-acid battery, which is mainly made of lead and its oxides, with sulfuric acid solution as the electrolyte. The battery acts as a voltage stabilizer for the vehicle's electrical system, mitigating impact voltages in the system and protecting the electronic equipment in the car.
When it comes to a battery paired with a 1000W motor, the first things to consider are voltage and how long you want it to run. Most electric vehicles or automotive systems operate at 12V or 48V—for example, my own modified electric bike runs on a 48V system. Dividing the power (1000W) by the voltage (48V) gives a current draw of about 21 amps. To run for one hour, the battery capacity should be at least 21 amp-hours. However, don’t rely solely on theoretical calculations, as startup or uphill climbs can cause current spikes that might blow fuses. That’s why I usually add a 20% buffer and opt for a 25Ah battery. Battery type is also crucial: lead-acid batteries are cheap but bulky, suitable for low-frequency use, while lithium batteries are lightweight, efficient, and long-lasting but more expensive. I’ve tried using a small lead-acid battery with a 1000W motor for short trips—it works, but for long distances, the limited range means frequent charging and replacements. So, a lithium battery matched to the voltage is the most hassle-free choice. Also, consider depth of discharge: for lead-acid, avoid draining beyond 80%, while lithium can safely handle 90%. Ignoring these details can lead to early battery failure. If you’re unsure about the voltage, check the manual or consult a technician—don’t risk circuit damage by guessing wrong.
