Check Mercedes-Benz Battery & Alternator No Tools or Voltmeter
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How can I check the battery voltage and alternator condition via cluster on a Mercedes-Benz? The following procedure is simple to check whether your Mercedes-Benz alternator is charging or if the battery is discharged.
At a Glance
- The cluster’s service menu can show battery or charging voltage on many older Mercedes models.
- Engine off: about 12.4 to 12.8 V is healthy depending on battery type.
- Engine running: roughly 13.5 to 14.8 V means the alternator is charging.
- Confirm a low reading with a multimeter at the battery or jump point.
- A scanner such as the YOUCANIC UCAN-II Pro shows live battery and charging voltage and reads all Mercedes modules.
Procedure
- Unlock the vehicle and go to the driver’s seat.
- Remove the push start button by pulling it out.
- Insert the key into the ignition and turn it with one click.
- Use the steering wheel buttons to show the miles on the cluster.
- Press the phone button and after 1 second, press the ok button and hold them both for five seconds.
- Select Vehicle Data on the cluster by pressing the ok button on the steering wheel.
- The cluster will show the Battery’s Voltage and Current.
- Start the vehicle, and you will notice that the voltage will go up, and the negative current turns positive, indicating that the current is going to the battery(charging). When the current is negative, the battery supplies voltage to the vehicle and discharges.
This is a great idea to check what is happening with your vehicle’s alternator.
This is a great idea to check what is happening with your vehicle’s alternator.Battery Charge Level
| State of Charge | Sealed or Flooded Lead Acid battery voltage | AGM battery voltage |
|---|---|---|
| 75% | 12.40 | 12.60 |
| 50% | 12.20 | 12.30 |
| 25% | 12.00 | 12.00 |
| 0% | 11.80 | 11.80 |
Check these troubleshooting and repair guides for more help on your Mercedes-Benz.
