When Slower Is Better

Protect EV batteries from temperature extremesHigh power DC Fast Chargers can minimize the amount of time it takes to charge your commercial EV fleet vehicle. Cutting Dwell Time (the amount of time your EV spends hooked up to a charger) increases the amount of time your EVs are available for use. And that’s good.

Except when it isn’t.

Like when the weather gets extreme. Really cold or really hot.

You see, EV batteries are fragile things. And to extend their life, they need to be charged at the right temperature. This will extend range and battery lifespan.

So, EV batteries use some of their stored energy to maintain an optimal battery temperature. That uses up some of the battery’s full charge. Which means the “fully charged” EV you fast charged overnight might not actually have a full charge. And that means less range. Fast charging a battery while it’s too hot or cold can damage a battery. And that means a shorter lifespan.

But there’s a work-around.

If you slow down the charging of your battery once you get to 80% charged, you can use the lower charging speed to continue charging and maintain battery temperature at appropriate levels. A Charge Management System (CMS) which uses Smart Charging can keep your EV battery at a safe temperature level and deliver a fully charged battery ready to go when your driver needs to get that EV on the road by automatically adjusting the rate at which the battery charges.

Similarly, if an EV battery has run down close to 0% charge, fast charging that battery as soon as it is connected will negatively impact the life of the battery. In a perfect world, EV batteries should always remain at least 20% charged. But the world is not perfect. Traffic, last minute changes to routes, and spur of the moment customer requests can all result in an EV battery returning to its charging station with less than 20% charge remaining.

When this happens, the natural tendency is to connect to the charger and get that EV charged as fast as possible. This is exactly what you should not do if you have the luxury of time to charge your EV. When an EV battery has dropped below 20% charge, it should be charged at a lower rate to help extend the life of the battery.

Again, there is a work-around. A Charge Management System (CMS) which uses Smart Charging can reduce the rate of charging until the battery is 20% charged. Once this threshold is reached, the CMS can tap into the full capabilities of your DC Fast Charger and increase the rate of charging. Combining this scenario with the previous example, your CMS can then throttle back the speed of charging once the EV battery is 80% charged.

EVauto software automatically adjusts charging speed based on temperature and state-of-charge, and in doing so provides better long-term EV battery performance than other CMS software options can deliver. This saves you money in the short term – by reducing charging costs – and in the long term – by extending battery life.

Here’s another way to look at it:

With great power comes great responsibility.

A DC Fast Charger gives you the power to minimize Dwell Time and maximize time on the road. But it also maximizes your ability to shorten the life of your battery. As a Fleet Manager, charging your EV fleet in a way that maximizes the life of your EV fleet’s batteries is your responsibility.

Be mindful of it.

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