Why would I want to discharge my Electric Vehicle when I get back to base?

“Can I ask a question?”, the gentleman interjected.  “Sure”, I said, pausing my presentation.  “Why on earth would I want to discharge my Electric Vehicle when I get back to base?”


It was Friday, a roundtable discussion with light commercial vehicle owners.  The questioner continued, “Why wouldn’t I want to simply charge it so it’s ready for me to use for my deliveries tomorrow?”

It’s an excellent question.

In a world where time is money and courier margins are increasingly squeezed, every second counts.  You want to be ready for the next day’s work.  Surely your Electric Vehicle (EV) should be charged back to 100% as soon as possible so it’s ready, just like your mobile phone when you get up in the morning?

The mobile phone comparison is a good one and illuminating as we consider this gentleman’s very reasonable question.  Have you ever wondered why the first step with a new phone is to plug it in to charge?  Afterall, mobile phone manufacturers put so much effort into making the un-boxing experience a pleasant one, only for you to have to watch your shiny new toy from a distance as it is attached by a cable to the wall for the next hours.

The answer is to do with battery health.  Leaving Lithium-Ion batteries at very high or very low states-of-charge for long period is well-known to reduce the lifetime and performance of this type of battery.  Hence why new phones come only partly charged.

Now back to cars and my interrogator.

EVs are not as different to mobiles as you might think.  Charging an EV to 100% as soon as it is done may lower a sense of anxiety by knowing it’s ready for use in the morning.  But it can be detrimental to the battery’s health, just like the Lithium-Ion battery in your phone.  There is actually benefit to your battery if you can wait to charge until the last possible moment.

But the benefits of smart charging go beyond simply extending (or maintaining) the range of your EV by looking after the battery’s health.

By charging at times when energy is cheap, the cost of running your delivery van can be reduced.  And, using so-called vehicle-to-grid technology, you can even use the battery in your vehicle to power your facility, sending energy back into your depot and reducing the higher-cost energy you might otherwise have had to buy.

And if these savings on your building’s energy bill weren’t enough, it’s now possible to sell this energy as flexible capacity which National Grid and local Distribution Network Operators will pay you for.   Which means that your EV could even earn you money, even as it is sat in your depot awaiting the next delivery. 

So, why would you want to discharge your EV when you get back to base?  Because it could save money on your bills, reduce your carbon footprint and even earn you revenue.

This is why we’re involved in E-flex, a project looking to see this work in the real-world.  If you have Nissan or Mitsubishi vehicles in your fleet and are interested in exploring this with us, find out more at www.e-flex.co.uk.