Most likely, yes! Under typical conditions, the battery found in Hybrids (NiMH) are expected to last about 5-8 years, though prolonged rest periods or getting overheated by strenuous charging and discharging cycles (such as when driving in mountainous terrain on a regular basis) can shorten that life expectancy.
For a typical driver, under optimal conditions an SLA (Sealed lead-Acid) battery can be expected to last about 3-6 years, though even a single deep discharge can ruin it, no matter its age.
A Deeper Look
Hybrids Usually Use Two Types of Batteries
Hybrid electric vehicles (HEVs) have two batteries. Like a normal car, they have a low-voltage battery that powers systems such as the stereo, computers, and navigation system. They also have a high-voltage battery, called the traction battery, that powers systems like the vehicle's electric motor-generator unit and air conditioning compressor. The traction battery is the expensive one because of its complexity and the exotic materials required to construct it. Most people know how long to expect their car battery to last, so a common question is whether or not their hybrid battery will last as long as their standard battery.
So… What's the Difference? Why do Car Batteries Fail?
The low-voltage battery in a hybrid vehicle is a sealed lead-acid (SLA) battery. These are heavy but relatively simple. Without going into too much detail about their construction or electrochemistry, they're constructed of a series of lead plates separated by an electrolyte, in this case a solution of sulfuric acid and water. When the battery is discharged, lead sulfate forms on the surface of the plates, releasing stored energy and gradually reducing the surface area of the plates and the battery's power. During charging, this substance is dissolved, and the battery's sulfuric acid level rises back to normal. Over time the sulfate crystallizes and can no longer be dissolved during charging, degrading the battery's overall capacity permanently. For a typical driver, under optimal conditions an SLA can be expected to last about 3-6 years, though even a single deep discharge can ruin it, no matter its age.
The traction battery in most hybrids is a Nickel-Metal Hydride (NiMH) battery. These are constructed of cells composed of nickel and metal hydride plates, separated by a potassium hydroxide electrolyte. Over time, barring the battery being overheated or physically damaged, NiMH batteries "go bad" because a resistive layer of crystals forms on the surface of the nickel. As with SLA batteries, time is more important than mileage to this process, and driving conditions and habits are more important than either. Under typical conditions, NiMH batteries are expected to last about 5-8 years, though prolonged rest periods or getting overheated by strenuous charging and discharging cycles (such as when driving in mountainous terrain on a regular basis) can shorten that life expectancy.
Can Anything Be Done To Extend the Life of a Hybrid's Batteries?
In the case of the vehicle's low-voltage SLA battery, unfortunately the answer is a conditional "no." Proper maintenance, driving the vehicle daily, or putting the battery on a trickle charger during long storage periods can maximize the battery's life expectancy, but once the sulfate is crystallized over most of the surface of the lead plates, the battery can't be revived as a whole unit and must be replaced. Fortunately, SLA batteries are made of fairly common materials and are thus reasonably affordable.