The traction battery (high voltage battery) of a hybrid car is one of the most reliable parts with a reported average life span of ten years. Some people have used theirs way beyond that. As the car ages, the battery becoming weak is inevitable.
What is a hybrid battery?
When people say hybrid battery, they refer to the high voltage/traction battery.
It is different from the normal 12 volts type found in a conventional car.
In a hybrid vehicle, the 12 volts battery is merely used to power accessories and control units.
The high voltage battery is used to power the electric motors which drives the wheels.
What causes the hybrid battery to become weak?
1. Normal ageing of the battery can make it to become weak meaning that it served during its useful life.
2. Putting transmission in neutral at stops. This might not apply to every hybrid car that has been produced. Whenever the transmission is in neutral, the battery does not charge. This is the way it is designed to operate. This is one area where driving a hybrid is different from driving a conventional internal combustion unit cars.