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Prevent the Single Biggest
Cause of Breakdowns

Frotcom, as standard, monitors your vehicle's battery health — giving you visibility to act before a failure occurs.

Prevent van breakdowns UK — fleet vehicle battery voltage monitoring with Frotcom

Flat batteries are the leading cause of car and van breakdowns. With Frotcom, you gain real-time visibility into your vehicle's battery health, allowing you to act before a failure occurs.

As standard, Frotcom continuously monitors your vehicle's battery by measuring its voltage. But how should you interpret these readings, and when should an alarm be triggered?

This guide explains how to understand voltage measurements. For additional advice — such as guidance on other battery types — please contact your Frotcom account manager.

Battery Voltage Cheat Sheet

Also known as: "Is Your Battery Happy?"

🔋

Engine Off (Battery at Rest)

12.6 – 12.8 V
Happy & Full
100% charged — battery in excellent health.
12.4 – 12.5 V
Slightly Hungry
Around 75% charged — monitor but not urgent.
12.2 – 12.3 V
Getting Weak
50% charged — cold starts may struggle.
12.0 V or less
Running on Empty
Vehicle may not start — action needed.
< 11.8 V
Zombie Battery
Very discharged or failing — replace immediately.
🚗

Engine On (Alternator Charging)

13.7 – 14.7 V
All Good
Alternator doing its job perfectly.
> 15 V
Overcharging
Alternator or regulator issue — battery damage risk.
< 13 V
Undercharging
Could be alternator, belt, or bad connections.
🛠️

Pro Tips for Testing

Resting Test

Check after the vehicle has been off for a few hours — this gives you the true resting voltage.

Cranking Test

Starting the engine shouldn't drop below ~10V. If it does, your battery is weak.

Running Test

With lights and AC on, voltage should stay in the 13.7–14.7V sweet spot.

Quick Takeaway

12.6V+ engine off = battery healthy
13.7–14.7V engine on = alternator healthy

Anything outside these ranges? Don't wait for a breakdown — Frotcom's real-time battery monitoring means your team can act before the vehicle fails at the roadside.

Want to understand how Frotcom monitors battery health across your fleet?

Contact Us →

Don't Wait for a Breakdown.
Act on the Data.

Frotcom monitors battery health across your fleet as standard — giving you the visibility to act before a vehicle fails at the roadside.

Get in touch with Frotcom UK