Hybrid Battery Health: 7 Pro Tips

Quick Facts About Hybrid Battery Health

• Repeated exposure to extreme heat reduces hybrid battery life.
• Frequent Level 3 DC fast charging shortens the life expectancy of a plug-in hybrid battery.
• Habitual charging to 100% affects a plug-in hybrid battery’s longevity.

A common issue contributing to consumer resistance to hybrids is the specter of paying thousands of dollars to replace the battery somewhere down the road. This is not surprising because, as with the human heart, we can abuse a hybrid’s battery (the heart of the vehicle) through neglect and abuse, such as overcharging it and exposing it to extreme temperatures.

Pairing a battery-fueled electric motor with an internal combustion engine (ICE) to propel a vehicle can enhance fuel economy and increase torque, which determines the rate of acceleration. These are valuable benefits in performance and efficiency. It begs the question: Why doesn’t everyone drive a hybrid? One consistent answer to that question: Worries about battery replacement costs.

• How Long Will a Hybrid Battery Last?

• 7 Tips to Maintain Hybrid Battery Health

• Warning Signs of Hybrid Battery Failure

• How Much Does a Hybrid Battery Cost to Replace?

• Our Take

How Long Will a Hybrid Battery Last?

On average, today’s hybrid batteries last at least 10 years, or between 100,000 to 150,000 miles. Kia suggests its hybrid batteries will last 150,000 miles or up to 15 years before needing replacement. As a matter of law, the federal government insists carmakers warranty hybrid and electric vehicle batteries for a minimum of 8 years or 100,000 miles, whichever happens first. Beginning with the 2026 model year, California requires hybrid and electric vehicle (EV) batteries to be able to recharge to at least 70% of their original capacity for 10 years or 150,000 miles. Following this lead, Toyota now warranties its hybrid and EV batteries for 10 years or 150,000 miles. In other words, these batteries can last a long time. So, then how can you squeeze the maximum years and miles out of a hybrid battery? Continue reading.

RELATED: EV Battery Health: The Essential Guide

How Do Hybrid Battery Warranties Work?

Total hybrid battery failure is uncommon. However, over time and use, hybrid batteries degrade. That is, their charge-holding capability declines. That’s the cold, hard truth. Here’s the good part: Your battery doesn’t have to utterly fail for the warranty to kick in. Nope, several car companies’ coverage begins once a battery’s charge capacity degrades to a certain percentage of the original maximum. For example, Kia’s hybrid battery warranty comes into play when the battery charge capacity drops below 70%, if the warranty is still in effect. When that occurs, Kia will restore or replace the hybrid battery to at least 70% capacity.

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7 Tips to Maintain Hybrid Battery Health

Like your smartphone’s battery, a hybrid’s battery gradually loses its charge capacity over time, leading to more frequent charging. In more recent hybrid models, hybrid batteries are lithium-ion, just like smartphones. Some older model hybrids used nickel-metal hydride (NiMH) batteries. Although our tips are geared toward lithium-ion versions, they mostly apply to NiMH batteries, as well. We’ve lumped plug-in hybrid (PHEV) batteries in with batteries of conventional hybrids like the Toyota Prius. We’ve noted if a tip is strictly for a plug-in hybrid or a hybrid vehicle that doesn’t require plugging in for charging from an external power source.

1. Minimize exposure to extreme temperatures: Batteries simply do not perform well in more extreme temperatures. The ideal range for hybrid battery efficiency and performance is in the range of 59 to 95 degrees Fahrenheit. The greater the temperature difference from this optimum range, the more severe the issues become. Repeated exposure to extreme heat wears out the battery, while exposure to extreme cold degrades its efficiency (reduces its range). NOTE: Extreme cold also radically increases charging times.
2. Refrain from charging to 100% (PHEV): Most experts agree, repeated charging to 100% capacity reduces battery life. Many newer plug-in hybrids have battery management systems that can cap battery charging to 80% or so. If your plug-in hybrid electric vehicle doesn’t come with this feature, keep tabs on the charging level and unplug at 80%.
3. Never completely drain the battery (PHEV): Allowing your battery to discharge to zero is every bit as harmful as charging it to 100%. A good rule of thumb is to never let the level of charge dip below 20%.
4. Avoid long periods of non-use: Even when parked, the charge in a hybrid battery is depleting. Allowing it to totally discharge and then sit idle for days, not to mention weeks or months, will whittle away its life expectancy. For a hybrid, that means at least running the engine every week or two for 20 to 30 minutes. Note: Just as important as avoiding periods of non-use, regular moderate discharging and charging of a hybrid battery will enhance its life span.
5. Occasionally rest the battery (PHEV): This may seem at odds with No. 4, but stick with us for a second. Resting the battery refers to driving the vehicle on the combustion engine alone, even if you have over 20% of charge in the battery. Your PHEV provides that option, and you should take it every so often. Batteries, like anything else, last longer with lighter use.
6. Minimize fast charging (PHEV):  Force feeding the electric charge into a battery via a Level 3 DC fast charger to an 80% charge is a welcome time saver. This is particularly true when away from home. However, repeated fast charging degrades the battery. Kia, makers of the Sorento and Niro PHEVs, says fast charging can rob roughly 10% of a battery’s life over eight years compared to Level 2 charging.
7. Regular battery maintenance: Maintaining a hybrid battery is as simple as ensuring the battery case is dirt-free. The cooling fan is a key component of a hybrid system. If the cooling fan isn’t operating at maximum efficiency, it can lead to battery degradation. Remember, the cooling fan also includes a filter, like an engine’s air filter, that must be periodically cleaned or replaced.

RELATED: What Is a Hybrid?

Warning Signs of Hybrid Battery Failure

• Illuminated dashboard warning light(s): Dashboard warning lights will pop on when the hybrid battery begins to fail. These may be assorted warning lights, like the check hybrid engine light or even a message requesting a hybrid system check.
• Electric motor not engaging when accelerating: If the electric motor fails to kick in under hard acceleration, it’s probably a battery issue.
• Reduced fuel economy: If your fuel economy numbers begin dropping, it could be a sign the battery is dying.

How Much Does a Hybrid Battery Cost to Replace?

Here’s the not-so-good news: Hybrid and EV batteries cost a lot to make. The better news is, hybrid batteries cost much less than EV batteries. Still, depending on the make and model of vehicle, you can expect to spend somewhere between $2,000 and $8,000 to replace a failed hybrid battery.  

Our Take

One way or another, every battery eventually fails — smartphone, flashlight, or a hybrid car. Most hybrid batteries are covered for 8 years or 100,000 miles, which is better than the powertrain warranties on the majority of new vehicles. Although hybrid batteries can cost a bundle to replace, generous warranties often mitigate much of the replacement cost. We like hybrids, particularly traditional hybrids like the Toyota Prius. Moreover, we wouldn’t miss out on the advantages of a hybrid out of anxiety over battery failure somewhere in the future.

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