Toyota Nation Forum banner

1 - 3 of 3 Posts

·
Registered
Joined
·
1 Posts
Discussion Starter #1
Hello this summer my car spent too much gas .
It is 2006 model,Toyota highlander hybrid -6 cilinder ,3.3
230 000 miles
The tires are good,the filters are changed,good oil,always premium gas.
No lights on, and no complaints when driving.
I am driving with ac on because I live in Vegas.
Any suggestions?
Thank you
 

·
Moderator
Joined
·
6,157 Posts
No need for premium but that's your call.
Real crappy mpg, under ALL other components having regular maintenance and in functional order is sign of hybrid battery going south.
 

·
Moderator
Joined
·
6,157 Posts
How to know when hybrid battery is failing
What causes hybrid batteries to degrade and fail?

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.
This graph depicts the typical life cycle of a Hybrid Electric Vehicle (HEV) hybrid battery:




There are three major phases of hybrid battery lifespan. Usable capacity and performance decreasing as the battery ages:
Typically begins: Typically ends: Phase 1: Healthy hybrid battery New Vehicle 3-6 years Phase 2: Weakened/weakening hybrid battery 3-6 years 5-11 years Phase 3: "Failed" hybrid battery (DTC code present) 5-11 years

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:
(1) usable cell capacity is reduced
(2) 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. The car's battery management system uses only a limited range of the battery cells actual physical capacity (80%-40% for Toyota and 80%-20% for Honda). As the usable capacity decreases and the cells become further and further out of balance with each other, the vehicle us 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.


How do I know if my hybrid battery is failing?





There are several subtle cues displayed by a hybrid vehicle that can alert you to degrading hybrid battery capacity & performance. If not acted upon, the battery will ultimately display a fault code for battery 'failure'. By paying attention to the warning signs and performing preventative care on the battery before it 'fails', you can easily improve battery health and prolong its life. Prolong Battery Systems will improve hybrid battery performance, save you thousands of dollars in avoided replacement hybrid battery costs, and benefit the environment by requiring one less hybrid battery to be manufactured. (Note: The symptoms described below are applicable to Toyota vehicles. Honda vehicles display similar symptoms. Feel free to give us a call and we can describe the Honda symptoms for you.)


The first indication of decreased battery performance is a reduction on fuel economy and diminished vehicle performance. The vehicle does not get the same fuel mileage that it used to and it feels sluggish - lacking in power during acceleration. If equipped, EV mode may be less frequent and for shorter duration then when the vehicle was newer. This happens because as the hybrid battery weakens, the vehicle is forced to use less of the battery and more of the gas engine. It also spends more time charging the hybrid battery in the background (i.e. not shown on the dash). Both of these behaviors reduce fuel economy. This can last for several months as the battery weakens and fuel economy/performance progressively decreases. Note: sometimes under inflated tires can cause similar symptoms. We recommend checking your tire pressure to be sure that is not the cause of decreased fuel economy
 
1 - 3 of 3 Posts
Top