You can use a voltage meter. A fully charged battery of 12v should read 12.6v with negative cable disconnected, and all accessories off. It should not fall below 12.4v when fully charged. This is the easiest way to check.
load test
load test
A battery stores charge and supplies voltage and current. A kilowatt (KW) is a measure of power = Volts x Amps.
Cold cranking amps It is a measure of the battery's "power" when the temperature is near freezing.
The 'V' on a battery typically stands for voltage, which is a measure of the electrical potential difference between the positive and negative terminals of the battery. It indicates the strength of the battery's electrical force or power output.
The amount of power in the battery is a function of the time Erik runs the computer on the battery.
The letters Wh means watt hours. this is how many hours of power the battery can store. The larger the number, the more power the battery can store. This is important for laptops, smartphones, and tablets. or Another way to measure the capacity of the battery is in watt-hours(wh). wh is calculated by multiplying the number of Amps with the battery voltage.
A battery does not produce power, it just stores power. The alternator produces the DC voltage the battery stores. As the power is taken from the battery it is replenished by the alternator.
"Open circuit voltage" is a characteristic of a battery or power supply. You measure it exactly as the term suggests ... disconnect any load from it (or open the ON/OFF switch), and measure the voltage across the terminals of the battery or power supply while it's not supplying current to anything.
To measure battery current, you can use a multimeter set to measure current in series with the battery. Connect the multimeter in series between the battery and the load to measure the current flowing from the battery to the load. Make sure to select the appropriate current range on the multimeter to avoid damaging the instrument.
No. A battery is considered to be DC power.
If your battery is dead and you connect the power supply with your battery installed, the battery will automatically start charging. If you wish to run your MacBook off your power supply only, simply remove your battery from your MacBook and connect the power supply. You will then be running solely on the power supply. If you battery becomes fully charged while your power supply is connected, you MacBook will switch to the power connector as it's power source - preserving the battery.