12V vs 24V Tachographs
Understanding voltage systems and selecting the correct tachograph for your vehicle
⚠ Critical: Wrong voltage will damage equipment
Installing a 12V tachograph in a 24V vehicle (or vice versa) will damage the tachograph and potentially your vehicle's electrical system. Always verify your vehicle's voltage before ordering.
What Is Voltage?
Voltage is the electrical potential in your vehicle's system. Commercial vehicles use two standard voltages for their tachographs and other electrical equipment.
12V Tachographs
Common in:
- • Cars
- • Light vans (up to ~3.5 tonnes)
- • Small pick-up trucks
- • Most light commercial vehicles
Characteristics:
- • Single 12V battery
- • Lower power requirements
- • Smaller electrical components
- • More common in consumer vehicles
24V Tachographs
Common in:
- • Lorries and HGVs
- • Large commercial vehicles
- • Heavy goods vehicles (over ~3.5 tonnes)
- • Buses and coaches
- • Tippers and specialist vehicles
Characteristics:
- • Two 12V batteries in series (totalling 24V)
- • Higher power capacity
- • Larger electrical components
- • Standard for heavy commercial vehicles
How to Identify Your Vehicle's Voltage
Method 1: Check the Battery
Look under the bonnet at your vehicle's battery/batteries. The battery will have text indicating voltage. 12V vehicles have one battery marked "12V". 24V vehicles have two batteries marked "12V" each (connected in series).
Method 2: Check Vehicle Documentation
- • Vehicle manual or handbook
- • Registration document
- • Service receipts mentioning electrical work
- • Previous tachograph specification sheets
Method 3: Ask the Manufacturer or Dealer
Contact your vehicle manufacturer or dealer with your vehicle registration or VIN (Vehicle Identification Number). They can confirm the electrical system voltage.
Method 4: Check Existing Tachograph
If your vehicle already has a tachograph, it will be 12V or 24V depending on your vehicle. The voltage will usually be printed on the unit label or in the documentation.
Installing the Wrong Voltage
12V Unit in a 24V Vehicle:
- • Immediate electrical failure of the tachograph
- • Risk of fire/explosion of 12V components
- • Damage to vehicle's electrical system
- • Potential safety hazard
- • Non-compliance with regulations
24V Unit in a 12V Vehicle:
- • Electrical overload and burnout
- • Damage to vehicle's 12V components
- • Potential battery damage
- • Risk of electrical fire
- • Vehicle unable to start or operate safely
Our Products
We supply both 12V and 24V tachographs. When ordering, ensure you specify the correct voltage for your vehicle. Our team will confirm voltage before sending any equipment.
Example Voltages in Our Products:
- • VDO Series 2 1381: Available in 12V and 24V variants
- • Kienzle units: Available in 12V and 24V versions
- • Stoneridge SE5000: Check specification for voltage
When to Ask for Help
If you're unsure about your vehicle's voltage, don't guess. Contact us with your vehicle details and we'll help ensure you order the correct equipment.
✓ We verify voltage before shipping
When you order from us, we'll confirm your vehicle's voltage requirements before sending any equipment.
Call for assistance: +44 7436 072349