What is the best way to charge my Nissan LEAF?

Now that is probably one of the most significant questions that many of us have on our minds, isn’t it? As you have probably heard by now, there are three types (or levels) of charge for all Electric Vehicles (EVs), not just the Nissan LEAF. We will quickly review them.

Charging Levels available for Electric Vehicles

Level One charging is included with the LEAF as standard equipment. This will have a plug that you just plug into your regular 110 volt AC outlet in your garage. If you have run your LEAF almost completely out of juice, this could take up to 20 hours according to Nissan. The circuit breaker would be rated likely at either 15 amps or 20 amps. The electric vehicle supply equipment (EVSE) supplied with the car would determine how much power it could safely draw and limit the power sent to the vehicle. One thing to keep in mind is this – not everyone (and perhaps most LEAF drivers) will not come close to using all of the battery capacity every day. It would be possible that these drivers could accomplish their daily driving needs, come home and plug into the 110 volt outlet, and the car could be charged to 100% capacity while they sleep.

Level Two charging uses twice the voltage (220 volts) and can charge the car from near empty to 100% in about eight hours. Nissan is recommending that a Level Two EVSE unit be installed in your garage, or where you will park your LEAF. Level Two EVSE units will be installed (and many are already installed) as publicly accessible stations to charge your EV.

Level Three charging will be the answer for many. Level Three can use very high voltage (440 volts) along with high current (amperage) to bring an empty LEAF battery up to 85% capacity in less than 30 minutes. The battery management system then kicks in to protect the battery. The last 15% will take about 90 minutes or so. For my money, it would be more efficient to unplug in 30 minutes and drive to the next Level Three charging station in the time that it would take to get that last 15 miles of range.

That battery management system just mentioned seems to be the key to EV battery life. Nissan has gone on record stating that the difference between 80% remaining capacity in ten years vs. 70% remaining capacity in ten years would be due to more Level Two vs. Level Three charging. In other words, the Level Three charging will take more of a toll on the battery over time. And since the Level One and Level Two systems will bring the battery to a full charge safely, that would be the recommended way to charge a battery, unless you needed to charge quickly.

Reference material shows that it is better to partially discharge lithium ion batteries, than to fully discharge them. The article is not perfectly representative of EV batteries as the capacity is significantly different. Here is a link to a Tesla forum with discussion about their real world battery experience. It would seem that regular “topping off” is less likely to harm them than deep discharging. Even the Tesla experience has a short track record though. We will talk more about the need for Level Three charging in our next post.