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I have a 2019 Camry SE Hynrid and I have a Scangauge which reads the state of charge of the high voltage battery. I note that at the high end of the recent charges it was only about 65% and at the low end about 45%. Not sure if anyone else has anything that measures state of charge as a percentage, but I would be very curious.
When at the 65% point it still shows two empty bars at the top but I have never seen it rise above that point.
Any input would be appreciated.
 

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It never charges above 80%. It's designed that way. Safety measure to prevent overcharging. Even if it shows full bars charge, it's still not fully charged. Don't worry about it.
 

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Based on your response, is it possible tht the bars really indicate a range from about 30% to about 80% and not 0 - 100 %, i do not seem to be able to see how the gauge is supposed to represent 100% if the system is only supposed to charge to 80%
 

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Ask Toyota. We had this discussed ad nauseam before. Though it does show full charge, battery itself is never at 100% charge. That's how batteries are.



I'd take this as decent explanation, though with bad grammar.


Even when the display is 0 bars the battery is not 0% charged.
(IIRC = 1 bar = 40%, 0 bar= 30% State of Charge)

The reason the battery is never fully charged is because it would takes too long to do. The battery does not stores power not linearly with time but exponentally with time; i.e. the HV battery initially quickly absorbs an electrical charges up to about 60% of its maximum state of charge rating and then recharges the next 40% of its maximum state of charge rating at slower and later even slower rate as it get closer and closer to 100% state of charge. By the time the battery is 70% recharged - the battery recharging rate has slowed down so slow it become very inefficient to capture any additional charge. The Prius also tries to protect the HV Battery from overcharging pass its 100% rated state of charge because that could shorten the lifespan of the battery as well.

The reason the battery is never allowed to fully discharge is because that would would shorten the lifespan of the battery. The Prius ICE will aggressively recharge the battery when the state of charge is about 40% to prevent the battery from aging prematurely.

The underlying design goal is to extend the lifespan of the battery so it will last over 10 years.


https://priuschat.com/threads/why-doesnt-the-battery-ever-charge-fully.106073/
https://www.greenhybrid.com/forums/f49/does-battery-ever-fully-charge-12563/
 
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