Power Pinchers: The Truth About What’s Draining Your Fleet Vehicle Batteries

When you’re busy running a fleet, you need to be able to rely on your vehicles, and there’s nothing more frustrating than discovering a flat battery. It’s a time-consuming problem and can end up costing the business a lot of money through unplanned downtime, lost revenue, and the maintenance required to get the vehicle running again.

There are plenty of potential causes for a drained battery, and more importantly, lots of things your business can do to ensure vehicle batteries are kept in good health, enabling you to keep your fleet running smoothly.

The good news? In-cab hardware such as Lightfoot’s driver coaching technology is unlikely to be behind your fleet’s battery drain! It’s easy to assume that any add-on devices might be the cause, but Lightfoot requires extremely little power to operate, so will not drain your vehicle battery. When up and running, Lightfoot requires less than 20 milliamps of power, and when the engine is switched off, the device enters sleep mode where it draws as little as 11 milliamps. This means you’d need to leave your fleet vehicle switched off for over 5000 consecutive hours – or 254 days – for Lightfoot to drain the battery!

So, what’s really causing your battery to go flat? Read on to discover the most likely power pinchers:

1. Vehicle faults

The call may be coming from inside the house if you find that a vehicle routinely suffers from battery issues.

A common problem is a phenomenon known as ‘parasitic draw’. This is when a faulty electrical component continues to draw power from the vehicle’s battery even when the engine is off. By failing to switch off automatically, the component makes it difficult for the battery to recharge, leading to battery drain.

The most likely parts to cause this include sensors, interior lights, alarms, computer modules, and relay switches. You’ll need to have a mechanic perform a parasitic draw test to diagnose if this is the issue and which component is to blame.

Another potential reason is a defective alternator. The alternator helps the battery stay charged as the vehicle is driven, and if it isn’t working correctly or can’t provide enough voltage, the battery won’t be charged effectively, causing it to go flat. Drivers may notice the vehicle making unusual noises or see the lights flickering if the alternator is to blame.

Loose or corroded battery terminals may also be the root cause of any power issues. This will prevent the battery from properly transmitting power, as well as interfering with its ability to recharge.

Make sure batteries are being checked regularly as part of your fleet vehicles’ regular maintenance schedule to eliminate any potential faults.

2. Environmental conditions

Another reason your vehicle battery might be feeling under the weather is, well, the weather. Extreme temperatures can affect its performance, leading to potential problems in both the depths of winter and the height of summer.

Cold weather has been shown to significantly impact batteries, reducing typical performance by as much as 60% in freezing temperatures. This is due to the chemical reactions that take place within the battery slowing down, leading to a decline in strength and efficiency and therefore a much higher likelihood of the battery dying.

At the other end of the scale, hot weather is also known to increase battery drain. Higher temperatures cause battery fluid to evaporate, resulting in a decreased capacity, potential corrosion, and higher chances of failure.

Keeping fleet vehicles in a garage or depot can help to prevent the problems caused by extreme weather conditions.

3. Use patterns

It may also be the way in which your fleet vehicles are being used that is causing needless battery drain.

If your drivers are frequently making short trips in their vehicles, this can damage the battery over time and lower its lifespan. It takes a large amount of power to get an engine running, which is why the alternator needs to recharge the battery over the course of the journey. On a short drive, there may not be enough time for the alternator to fully recharge the battery, and if this is the only usage a vehicle gets, the battery can quickly deteriorate.

Similarly, leaving a vehicle too long without it being driven can also drain the battery. This is often the case in older vehicles or those with ongoing issues, as the battery may already be weakened. Electronic systems within the vehicle will continue to draw a small amount of power even when dormant, and the battery can struggle to recharge if this carries on for an extended period of time.

To avoid such issues, it’s recommended that fleet vehicles are driven for a minimum of 45 minutes every 14 days to keep the battery in good health.

4. Human error

As well as the way your drivers use their fleet vehicles contributing to battery problems, ongoing power drain could also be down to simple mistakes or bad habits.

The most common reason? The vehicle not being turned off properly. It’s easily done, but if drivers leave the headlights or an interior light on, don’t shut the boot properly, or leave a door slightly ajar, this could be behind recurrent battery drain. The more this happens, the more it will degrade the battery, and if left long enough can lead to a vehicle without any power.

Remind drivers to always turn their vehicles off properly and consider making end of journey checks an integral part of daily vehicle maintenance.

5. Battery age

As a general rule, car and van batteries will last for around 5 years, although this will be determined by a number of factors including vehicle usage, climate, and driver behaviour.

As the battery ages, you may notice a drop in performance and more frequent problems such as corrosion, leading to a higher likelihood of the fleet vehicle being left without power. Even with frequent maintenance and preventative care, every vehicle’s battery will eventually reach the end of its lifespan and need to be replaced.

What about electric vehicles?

Just like petrol and diesel vehicles, electric cars and vans can experience battery problems due to extreme temperatures, vehicle faults, age, usage, and not being turned off properly.

However, when it comes to driving an EV, battery power is even more of a consideration than in a conventional vehicle, with any battery drain leading to a reduction in range.

That’s why when managing an electric fleet, it’s important to be mindful of other factors that can drain an EV battery – such as in-vehicle features. Whilst many of these are necessary for a comfortable driving experience, their use will influence journey range and needs to be factored in for any planned charging stops.

Here’s a look at how much faster the battery drains in a typical electric vehicle when different features are used:

• Heating – 17%
• Windscreen wipers – 15%
• Heated seats – 15%
• Demister – 12%
• Air con – 11%
• Sat nav – 5%

So, there you have it. Whilst it’s easy to assume that integrated technology such as a telematics device or driver training solution might be the cause of battery drain in a problematic fleet vehicle, the likelihood is that there are many other factors at play. By understanding these common causes of a flat battery, you can take the necessary steps to prevent further problems, reduce downtime, and keep your fleet operating reliably.

Want to help your fleet achieve its very best performance? Lightfoot’s award-winning technology coaches drivers in real-time, helping them to drive in a smoother, safer, and greener way, leading to improvements in MPG, road safety, carbon reduction, and EV range as a result.

Book your free technology trial today or contact our expert team to find out more.