# What voltage should a motorcycle battery read when running?

Contents

Motorcycle batteries operate between about 12 and 14.5V — any more than this puts a lot of stress on them. A fried reg/rec means you might see voltages of over 20V when revving high which is bad news for the battery.

## What voltage should a healthy motorcycle battery read?

Open circuit voltage for a fully, 100% charged AGM battery is 12.8 to 13.0 Volts. AGM batteries that are 75% to 100% charged will measure 12.5 to 12.8 volts. Conventional batteries have slightly lower open circuit Voltages: 12.6 volts (12.8 volts with Sulfate Stop) for 100% charge and 12.4 for 75% charge.

## What should battery voltage be while driving?

Fully charged automotive batteries should measure at 12.6 volts or above. When the engine is running, this measurement should be 13.7 to 14.7 volts.

## Does motorcycle battery charge while idling?

Technically, a motorcycle battery does charge while the motorcycle is idling though it does not provide as much amperage as when the motorcycle is at higher speeds. During a normal ride, a motorcycle provides about 13, 14, or 15 amps while idling only provides less than 1 amp.

## What voltage is needed to start a motorcycle?

You’ll need at least 12 volts under load to kick a motor over for any period of time long enough to start it. 12-14 volts is the range a battery should read out while running an engine…..as long as the electrical system is set up for 12 volts.

## How do you tell if a motorcycle battery is going bad?

Visual Inspection. The most obvious warning signs can be found through a simple visual inspection. Signs of a bad battery include broken terminals, a crack or bulge in the plastic casing, as well as any leaking fluid or discoloration. Sometimes, battery terminals can become corroded.

## What is the voltage of a half charged 12v battery?

Voltage on a fully charged battery will read 2.12 to 2.15 volts per cell, or 12.7 volts for a 12 volt battery.

Some common battery size codes used are: (ratings are approximate)

U1 34 to 40 Amp hours 12 volts
Group 24 70-85 Amp hours 12 volts
Group 27 85-105 Amp hours 12 volts

## What should a 12v battery read?

Check the reading. A fully charged battery will typically display a voltmeter reading of about 12.6 to 12.8 volts. If your voltmeter is showing a voltage anywhere between 12.4 and 12.8, that means your battery is in good shape. Any voltage above 12.9 volts is a good indicator that your battery has excessive voltage.

## What are the signs of a bad battery?

5 Unmistakable Signs Your Car Battery is Failing

• Clicking sound when you turn the key. …
• Slow crank. …
• Needing to press on the gas pedal to start. …
• Backfiring.
IT IS INTERESTING:  Best answer: Do you need to take a theory test for a moped?

## Is 14.5 volts too much?

Above 14.5 volts charging voltage, batteries have a greatly increased tendency to release excessive acidic vapors, hydrogen gas, and to corrode things around the battery. … 14.8 would start to be a worry (there might be liquid or corrosion on the battery) and 15 volts would be a real concern, but 14.6 is fine.

## What is the voltage of a fully charged 12v lead acid battery?

A 12-volt lead-acid battery that is fully charged often provides a voltage of about 12.7V. If the lead-acid battery only has 20% left, it will only deliver 11.6V.

## Can a battery show 12v and still be bad?

Sure. It could be showing a voltage higher than 12 volts and still be bad. If it is bad it will die or drop significantly when put under load. Battery testers don’t just measure voltage.