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Hybrid Battery Questions

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No. The time to replace your hybrid battery is when the car tells you.  You should have the car professionally diagnosed if you have any warning lights going on.  If you would like to be proactive about your Hybrid Battery condition, you can Hybrid Battery Repair to have us run a Hybrid Battery Test.  In case the Hybrid Battery condition is bad, we can recondition it, saving you $1,000 or more over purchasing new.

Hybrid storage for less than three months does not create a problem. If you plan to be storing your hybrid for a longer period, it’s a good idea to have the vehicle started up and run for 30 minutes every three months. If your hybrid is left dormant for even longer periods, you may need to have a professional test the state-of-charge, and potentially give the Nickel-metal-hydride batteries a boost.

There are several symptoms of hybrid battery failure. Rapid or instantaneous change of the battery status is an easily identifiable symptom. This information can be located on the multi-function display. As the Hybrid Battery deteriorates you will notice the battery graphic fluctuating between one bar and eight bars in less than 30 seconds.

Another sign of hybrid battery failure is an audible fan noise coming from the battery’s cooling fan that is located next to the rear passenger seat in the Prius and behind the rear seats in the Camry. When a battery is about to fail it may overheat causing the fan to run faster than normal as it attempts to keep your battery cool.

When the battery does fail the car will illuminate several warning lights on both the dashboard and the center display screen. A red triangle, VSC, and ABS light on the dashboard, along with a red car with an exclamation point over it on the center display are indicative of battery problems.

Eventually all batteries will fail. Hybrid Electric Vehicle (HEV) NiMh batteries have a life cycle. When the hybrid battery does not last as long as the rest of the vehicle, replacing it costs several thousand dollars and creates hazardous environmental waste. Delaying battery failure beyond the service life of the vehicle will reduce the negative environmental impact of hybrid vehicle ownership and save the vehicle owner thousands of dollars.

Each hybrid battery ‘pack’ is comprised of many individual battery cells. Consumer hybrid electric vehicles have anywhere from 120 to 240 individual battery cells. Each cell is about the size of a typical D cell battery. At the beginning of the hybrid battery’s life, each cell easily provides all of the energy needed to propel the vehicle and to stay in sync with other cells in the battery pack. As time progresses, the battery will start to degrade and the cells will fall out of sync with each other. Results of this degradation include the usable cell capacity is reduced and cells drift out of balance with each other (voltage delta).

The speed of this deterioration is determined by a variety of factors, including vehicle make/model, climate, driving habits, variation in battery cell construction, and more.

This battery deterioration means that the individual cells within the battery pack can have a different charge level and capacity – they are no longer ‘in sync’ with each other. Some cells can be ‘full’ while other cells in the same battery pack are ’empty’. The overall battery pack performance is limited by the vehicle’s battery management system to the weakest cell when discharging and the strongest cell while charging. As a result, the wider the cell imbalance, the narrower the usable range of the hybrid battery becomes. As the usable capacity decreases and the cells become further and further out of balance with each other, the vehicle is able to use less and less of the batteries actual capacity.  The vehicle cannot correct this imbalance problem on its own. The car cannot force the cells back into balance with each other.

If no attention is given to the hybrid battery, it will ‘fail’ and the check engine light/hybrid battery light will be illuminated.

Hybrid Battery Questions