Your driver arrives long before dawn to take the already-loaded trailer of goods down to another depot 300 miles away. You serviced and replaced the lorry’s battery just a few months ago. Everything should be fine. But it isn’t.
The driver climbs into the cab, blowing their cuppa to cool it down, and puts the keys in the engine. The engine slowly turns over, then gives a pitiful rattle as the starter gives up. It hasn’t got enough juice. The battery’s died. Again.
The lights weren’t left on, the radio’s been off, and nobody’s reported any other symptoms that might have made your technicians suspect a battery problem.
So why has this happened?
Why does it happen regularly, and to other vehicles in your fleet?
And how can you prevent the associated interruptions (and costs) from happening again?
Read on to find out…
Parasitic drains
A parasitic drain refers to when your vehicle’s battery continues to drain after the ignition has been switched off.
Modern fleets depend on a web of electronics, which could include telematics units, security systems, trackers, alarm systems and cameras. These all draw power, even with the ignition off, some more than others.
Over days and weeks when the vehicle isn’t in use, they turn from valuable applications to parasitic drains. A 12V battery loses charge slowly at first, then the discharge curve steepens once its voltage falls below around 12.4V. Your driver might not notice until the vehicle fails to start.
Older vehicles relied on fewer background loads simply because it wasn’t really possible back then. But today, a parked truck is never truly at rest. Refrigeration units, in particular, pull heavy loads on delivery vehicle batteries. If the battery is already weak, that extra drain pushes it to failure much quicker.
Solution: Regular parasitic drain testing. Once you have a routine established, you can compile data over time to identify battery trends. You’ll have real-life insights to know if action is needed, whether that’s rewiring, component repair or scheduled charging.
Alternator issues
Depending on the state of your vehicle’s electrical system, even a healthy alternator doesn’t always restore your battery to a full charge. Short runs with heavy accessory use, especially those of delivery vans and even more so in winter with heating systems, may leave the battery undercharged.
If this keeps on happening, it loses charge. Repeated undercharging leads to sulphation, which locks away part of the battery’s capacity. That lost capacity never comes back without careful external charging.
Faulty alternators or loose connections make matters worse. Your truck may appear to start fine, but the state of charge (SoC) creeps lower with every trip. In these sorts of cases, one long journey usually won’t fully undo weeks of undercharging, because the battery’s already suffering from sulphation.
Your battery problems become more pronounced in extreme temperatures. Cold weather slows chemical reactions in lead-acid batteries, so you have less power available. Heat accelerates corrosion, so the battery won’t last as long. A charging system already under strain will struggle to cope when these environmental stresses hit.
Solution: Voltage drop tests, alternator output checks and . These are crucial testing techniques that may demand slightly more time during servicing, but are so important. They’re the only way to identify if the vehicle’s electrical charging system is holding up under real-world conditions.
Charging and inspection routines
In many fleets, the typical policy is to run a vehicle until failure, then replace or recharge the battery. In other words, hope for the best until the best doesn’t arrive one day.
It certainly feels more productive in the moment. For example, you don’t need to spend as much time servicing your lorries, trucks and vans. However, once you factor in missed deliveries, staff overtime, late depot returns, recovery trucks and unhappy customers or suppliers, you’ll probably find a significant portion of your profit margins being eaten into.
So, what should you do instead? Here at Rotronics, we’re all about prevention and being proactive rather than reactive. It might feel like a drag in the moment, but keeping on top of your battery can significantly reduce unexpected breakdowns, up to 95% in one of our client’s cases.
Solution: We recommend adding simple battery testing routines to your workflow, either including them as part of regular servicing every couple of months, or introducing weekly checks (which give a more detailed range of data). Upload all the data to an analysis system like ROBIS. This will help you spot any worrying trends long before the vehicle itself experiences a start failure.
Rotronics is here to help
Rotronics has been working with fleet managers and technicians for many years.
We understand the market and know the best way to assist. Our specialist range of battery testers helps you monitor your fleet’s condition, while our battery chargers use advanced techniques to restore your batteries almost to full health and maximise their lifespans.
All of this comes together in ROBIS, our online portal where you can view, track and manage all your test results. For more information about ROBIS or our range of battery testers and chargers, reach out. Our friendly team will be happy to walk you through the many benefits and explain the immediate impact you’ll get from your investment. Our systems have helped many others before, and we’re sure you’ll experience the same.
