How Many Amps to Start a Car? Have you ever been curious about this? You might need to jump-start the car or buy a new battery, and knowing the amp requirements is necessary for these things.
Important Factors to Consider
There is no clear answer to the amp requirement for starting a vehicle. Several factors come into play, including the operating voltage and the condition of the starter and wires. But the key factors are the engine’s displacement, the type of oil used, and the ambient temperature. A small engine may only need 50 amps for the initial boost, but a larger engine will require more amps. Similarly, other factors also determine the number of amps.
Oil
The fuel used in the car or its viscosity, to be more precise, plays a role in determining the amps. For example, an engine using 5W-15 oil will start more easily than one using 40W oil.
Temperature
Ambient temperature actually affects the engine oil, not directly the battery’s amperage. Oil becomes thicker at colder temperatures, resisting free flow. For this reason, the battery consumes a greater amount of current at lower temperatures.
How Many Amps to Start a Car?
Most small and medium-sized cars will not need more than 400 amps. This is probably sufficient for most compact SUVs and light trucks. Larger vehicles will require more amps, probably 1,000 amps. Remember that the amps needed to start the engine are always lower than the battery’s cold cranking amps (CCA).
Another thing to consider is that a high-amp jump starter can start a car that requires fewer amps. For example, a 1,000-amp jump starter will work for a vehicle that needs 500 amps to start. But it will not be sufficient if the vehicle requires 1,300 amps.
If you buy a 400-amp device, it will not boost a car that needs 800 amps to start. But the car may not respond due to a dead battery. For example, you might have left your car radio or a light on all night, which drains the battery. In this case, a 400-amp unit can charge the battery, which can easily restart the engine.
Simply connect the power pack to your battery and wait a few minutes to let it recharge. Buying a high-amp power pack is the right decision, but a cheaper 400-amp pack is not bad either. You can use it more than 30 times to boost your vehicle effortlessly.
The Voltage Calculation
So, now you know how many amps it takes to start a car, but the estimation is a bit different for voltage. If you have a 6V battery, do not plug it into a 12V source, or it will explode.
The starter’s power is calculated in watts, which you get by multiplying volts by amps. For a 12V battery, the engine will need about 200 amps to start. But the figure will increase when the battery voltage drops.
So, the things to remember are that you can use a more powerful amp pack but not a more powerful volt pack.