I am just wondering about the range of charge levels people are noting on their traction battery in the 300h. In my case the battery has never showed 100% charge. Even after getting off the freeway and braking to slow down the maximum charge is 2 bars below 100%. I am not too worried as I am getting close to 40mpg now that it has warmed up. On the low side it gets down to about 2 bars worth of juice. I am talking about the little display between the speedo and the tach. Just wondering if others see the same behavior.
Thanks

 

I personally have never had it to full charge but i always am able to get it up to just 1 bar shy of full. And the lowest that the car will allow the battery to go down to is 2 bars, then the engine will start powering the electric motor which will charge the battery. Just remember the higher you keep your bars, the better mpg you will get. I bought my hybrid on Saturday so im learning how the optimal way to drive a hybrid is, and i must say its pretty cool. And when you see 38-40mpg, you cant help but smile.

 

Actually, I respectfully disagree with that assessment. If you are maintaining a higher charge (more bars), you aren't using your electric operation as much as possible. If you are maxing out your electric usage (thus saving the most gas), your batteries are going to spend more time closer to depletion rather than full charge.

After almost ten years driving two different Priuses, I can verify that maxing your mileage takes a different driving style. That does NOT mean you need to drive slow and potentially annoy those around you though. I have always found it best to accelerate right up to normal speed as you would in any conventional car, then ever-so-slightly back off the gas and see if it will go to battery. This will often occur on level ground up to speeds of about 35 MPH. If you can't maintain the speed of your surrounding traffic then you just have to give up and try again with a warm engine or better terrain conditions. Paying attention to our driving in the Prius could mean the difference of several miles to the gallon over a tank without compromising our driving/speed. When the Prius model was new, too many people would drive poorly (slow trying to maximize mileage) and tick off other drivers, giving all Prius owners a bad reputation. Make sure you don't become one of "those" drivers in your quest for better MPGs.

 

I agree with keeping the battery level low, I rarely have mine above 2 bars in city traffic yet I'm seeing 40+ mpg in Eco mode. The key is to use both petrol and electric power efficiently, being gentle with the throttle and letting the computer choose the right energy strategy because it's a lot smarter than the average bloke behind the wheel

I only see full or almost full battery levels after a long highway run. I usually use EV mode on the short drive from the off ramp to my house. Creeping around in a giant golf cart is fun.

 

I agree, the computer will assure best performance and longevity of the battery.

 

The problem with depleting the battery down to 2 bars is at stop lights or crawling traffic. The engine will kick on to recharge the battery, as you're going nowhere and you'll see the mpg starts to drop. We have some incredibly long traffics lights.

 

The car will "idle" in electric mode for a long time before the battery goes down one level, but that's only if the heater/AC is off and the engine is up to temp.

How long are your lights? I usually put the car into Park and wait. I don't turn the car off because it takes a while for everything to initialize on start-up, especially having the steering wheel go from fully retracted to its set position.

 

The traction battery just needs to recharge once it goes down to two bars, at idle or not. I have noticed that the climate control, even just the fan on will kick/keep engine on. I've notice too that the engine sometimes run above the two bars even when warmed up, and won't let you go to EVO mode.

No I don't shut off the engine even when the lights sometimes takes a few minutes to cycle thru.

 

Yeah, the hybrid computer is pretty much a black box and I've given up trying to second guess the thing. If I'm running around in town all day, I can never use EV mode because the computer complains about the battery level being too low. However the car will still run on electric motors only as long as the battery level is above 2 bars.

Beyond that, there are a lot of parameters the computer looks at before deciding what power source to use - engine temp, battery temp, state of charge, current draw, speed and throttle position. It's good that the computer figures all this out but part of me wishes we had more control, like how German plug-in hybrids can be set to run the engine to charge the batteries ahead of time before entering a congestion zone.

 

Don't worry about the traction battery gauge. The CPU will determine when it needs more power from the engines. I read somewhere that the best life expectancy for a rechargeable battery is between the extremes...more cycles of charging don't seem to hurt these batteries, but too much or too low a charge, and it'll reduce life. The car knows when to charge the battery....

 

It's fun getting technical

Our cars use NiMH batteries with something like 50% overprovisioning so they'll still hold a decent charge after the battery warranty runs out. I've heard of Prius owners changing individual worn cells to restore battery capacity. I'll worry about that in 8 years' time...

Tesla and most new hybrids use lithium ion cells that pack more power in a smaller space, but they're finicky when it comes to the right temperature, charge rate and state of charge. Interestingly Tesla has plenty of data with their Roadsters that shows these batteries can take a bit of abuse over the years, provided the control strategies are conservative. Maybe that's why Toyota is so reluctant to use lithium chemistries in its hybrids.