Is It Okay to Leave A Nissan Leaf Plugged In All the Time?

Considering the everyday use of electronic devices, such as your smart phone, it's clear that unplugging it as soon as it's fully charged ensures it doesn't overcharge. Similarly, the common belief is that leaving an electric vehicle, like a Nissan Leaf, plugged in for an indefinite period won't harm its battery life. But is this assumption accurate? Let's delve deeper into the topic.

Short Answer: Average Circumstances, Yes

Before we dive into specific circumstances, it's important to note that the charger for your Nissan Leaf is designed with safety features. These circuits help ensure that the car's battery does not overcharge, even if the Leaf remains plugged in for an extended period. The risk is present but juxtaposed against a greater risk of damage if you're dealing with car batteries and for the first time using a charger. The key phrase here is "extended period," as unattended charging can pose risks, especially in the case of car batteries.

Leaving the Nissan Leaf Plugged In

For most occasions, it is recommended to leave your Nissan Leaf unplugged but adequately charged. Plugging the car in and leaving it plugged in for weeks can potentially drain the vehicle's 12-volt battery. However, since the traction battery should retain its charge, you won't experience significant issues. Should the 12-volt battery be depleted, jump-starting the Leaf is as straightforward as jump-starting any other car. The underlying principle here is to avoid letting the battery deplete while the Leaf is plugged in, as this can cause issues.

Modern Nissan Leaf (2013 and Later)

For newer Nissan Leafs (2013 and later), the situation is somewhat different. These models come equipped with advanced battery management systems (BMS) that are designed to maximize battery longevity. Therefore, you are encouraged not to charge the Leaf beyond 80% if you don't require the full 100% range frequently. Charging the Leaf to 100% and leaving it plugged in for an extended period can damage the battery, leading to a shorter lifespan. If you need the full range one day, you can charge to 100% just before you leave. However, it's crucial not to leave the Leaf at 100% charge for a prolonged period, as this can negatively impact the battery life of any electric vehicle, not just the Nissan Leaf.

Dealership Practices

Dealerships often let new electric vehicles, including Nissan Leafs, sit for weeks at a 100% charge when they are not being test-driven. This practice, while seemingly harmless, can negatively impact the battery life. Your brand new electric vehicle, whether from Nissan or another manufacturer, will have noticeable damage to its battery compared to the factory specifications on the first day it comes off the lot. This is not due to poor manufacturing but rather a result of dealership ignorance or disinterest in how to properly care for an EV's battery.

Using an Extended Charging Cord

In some situations, you might need to extend the charging cord beyond the usual 3 meters from your home. In such cases, while it's technically possible to leave the car plugged in, you'll need a longer charging cord to accommodate the additional distance. A longer cord ensures that the charging process remains safe and efficient, even if you need to set up the charging point further away from your home.

Best Practices for Electric Vehicle Charging

The most recommended approach for charging modern electric vehicles is to set a specific charging level rather than charging to 100%. Isolating the battery to 80-90% of its capacity not only protects the battery but also ensures optimal performance. The BMS in your vehicle manages cell balancing, and a lower than 100% charge level allows the BMS to do a better job of bringing the cells to a balanced state. The feedback loops that the BMS uses to balance the cells work best when there is a larger difference to the ultimate aim point, which is why a lower charge level is often preferred.

Understanding these practices can help you make informed decisions about your electric vehicle's charging habits, ensuring that your Leaf remains in top condition for a longer period.