Seven Biggest Mistakes People Make with Their EV Battery That Will Cost You
How to maximize your EV battery for the longest life
Disclaimer: These are general tips designed to maximize your battery lifespan, not replace manufacturer information. Read your car’s manual, and follow all manufacturer advice and guidelines.
With modern Electric Vehicles (EVs), you can pretty much charge and drive and charge again, without too much thought to your battery. Manufacturers have built-in precautions so you can’t overcharge, over-discharge, or overheat: the three biggest killers of battery longevity. But while you don’t need to baby your battery, you do need to respect it. With proper management—and following the tips in this article—your battery could last decades.
EV batteries, like engines in conventional gas-powered vehicles, are designed for a long life but will wear out eventually. Protect your investment and bolster your future resale value by avoiding the five biggest mistakes EV owners make.
1. Overcharging the Battery
An EV battery, like porridge and planets, does best in the Goldilocks Zone.
Never let your battery sit at 100% charge. Generally speaking, lithium-ion batteries do best when they operate in the 30%-80% charge range. Although it may take some extra planning, prolonging the time spent within that middle range may extend the life of your battery. One reason that batteries in mobile devices only last a couple of years is that they are pushed to their maximum daily, fully charged to fully drained.
Continuously charging to full capacity is stressful on your battery. If you don’t need the maximum charge, don’t use it. This is why most manufacturers offer “standard” or “normal” charge levels, which do not charge the battery up to the highest level but instead keep them at 80%. By all means, do the full charge when you need it, but do it right before you start the trip. Leaving a battery at max charge for even relatively short periods of time can possibly affect longevity.
2. Running the EV Battery Down to Zero
Conversely, leaving your battery in a low level (below 30%) charge state for an extended period may also impact its life.
Lithium-ion batteries prefer a partial cycle rather than a deep discharge or drain. Most manufacturers protect batteries from becoming completely discharged - a state that can render the battery permanently unusable depending on the level of degradation. Since lithium-ion batteries do not have a memory effect, there is no harm in using your vehicle - and charger - often. Not only will this avoid excessive battery wear, it will also mean that, with a little planning, you will arrive at your destination with range to spare for years to come.
One additional advantage of not charging all the way up is that it leaves room to store energy from regenerative braking, resulting in lower charging costs. When the batteries are full or near full, regenerative braking will be disabled to avoid overcharging.
3. Charging Too Often
The third mistake that people make with their EV batteries? Charging too often. Generally speaking, don’t charge every day unless you need to. Natural degradation may occur in the battery based on the number of charging cycles that are used over its lifespan.
EV Battery performance and durability can deteriorate if the charger is used constantly. Charging should be minimized in order to help prolong high voltage battery life.
The general rule of thumb is to plug in and charge whenever you can, but not every time you drive. That may mean plugging your car in semi-nightly to maintain a reasonable level of charge depending on your commute. Or, if you are without a home charger, that may mean regular charging when you are able.
Keeping the battery at 30%-80% charged and minimizing the number of charges - vs charging the battery to 100% and/or charging every drive cycle - will keep the battery performance in optimal condition. For most EV owners, this just becomes habit. Just like regular trips to the gas station and checking your oil was simply what you did with your gas-powered vehicle.
4. Not Balancing Their EV Battery
Lithium-ion batteries are designed to minimize the memory issues often found in older battery technologies, however the battery packs in EVs are more complex and often comprised of
multiple individual batteries - often as many as 7000 individual cells - packed together into removable modules. Battery balancing is about maximizing your battery’s capacity and evening out the charge distribution.
Modern EV batteries include an automatic battery balancing component, but for older models, there are steps that you can take to help the process along.
While you may never take long trips that need the absolute maximum range, a periodic maximum charge is helpful to your battery’s management system. A quarterly maximum charge may be beneficial to the lifespan of your EV battery. Keep in mind, however, that after you fully charge you should not let it sit, as stated in #1. Do this right before a trip.
5. Overusing DC Quick Charging
DC quick charging is very useful if you need to drive more than the vehicle’s single-charge range in a single day, or you just simply forgot to charge up last night and are hovering below the 30% range. DC quick chargers can dump upwards of 130 kms of range into the Kia Soul in 30 minutes. However, the batteries pay a price for this convenience.
Battery performance and durability can deteriorate if the DC charger is used constantly.
Use of DC charging should be minimized in order to help prolong battery life. The life expectancy of most EV batteries is about 70-80 percent of capacity after 10 years of normal use. It is theorized that frequent use of fast charging - more than once or twice per day - will cost you about 1 percent of capacity per year. Which basically means very frequent users of fast chargers can expect performance on the lower end of the normal range.
Level 2 AC charging is recommended to keep the battery in optimal condition. Level 2 chargers are the most efficient home charging option and are also the most common to find at free charging stations around town. Providing 240v power, it takes 6 to 14 hours to fully charge an EV, or 4 to 8 hours for a PHEV.
6. Improperly Storing Their EV
The capacity of an EV battery may decrease over time when the vehicle is stored in high temperatures and temporarily in low temperatures. If the vehicle will not be in use for an extended period of time, it’s recommended that you charge the battery once every three months to prevent it from fully discharging. If you can, store your EV inside away from extreme temperatures.
7. Not Using the On-board Computer
EVs employ sophisticated technology with high-tech on-board interactive computers to match. Most modern EVs have fail-safes and built-in precautions so you don’t have to spend time worrying about charging - or not charging - your EV.
Trust in the technology and get to know it better.
The menu in the 2020 Kia Soul, for example, has several menu options including available range; energy information detailing battery and energy consumption; power consumption to check the current energy consumption for each system of the vehicle; battery information including reachable range, battery power remaining, and expected charging time for each charger type; and charge management, plus ECO driving, and EV settings. This menu essentially contains everything you need to properly manage and maintain the longevity of your battery.
Driving habits and conditions will affect battery life regardless of how you maintain your battery: driving aggressively or in extreme conditions such as heat, cold or altitude will cause the battery to lose capacity faster.
But keeping your battery in good condition by driving reasonably and following our tips and your manufacturer's advice will all have a positive impact on the lifespan of your battery.