Hybrid charging variables

Welcome to the group! I just started my second year with the car. I am no expert on this car but these are my observations and experiences. I don't think keeping the rpm's up will do any good. Overall, light throttle is what keeps you in ev mode and pretty much anytime the ev light is off, you are creating a charge. Sometimes on the highway I will switch to sport mode until the battery fully charges, then switch to eco. The car does seem to have a little more electric torque when the battery is over 3/4 but overall it doesn't increase mpg. I think light braking works best for regen braking. Even coasting will provide regen braking but I try to watch the power gauge as I brake and keep from comlletely burying the gauge with the idea that when the gauge is buried, that is when the wheel brakes kick in. I can easily get 50+mpg around town if I feather the gas and stay below 50 mpg. I am no hard core hyper miler, but I just enjoy driving for the high number. I estimate I am close to 38 mpg over 16,000 miles and have never gotten less than 34 mpg on a tank of gas, even in the winter. I think I could do even better if I was the only one driving the car, but my wife has a lead foot.

DailyD said:

...On traditional vehicles, higher RPMs lead to higher charging rate of the 12v battery: Does gas engine RPM similarly effect the charge rate of the hybrid battery? As in could I strategically use lower gears to gain more charge? And does it charge much or at all when just idling (like if I use remote start in winter?)

Also, with regen braking... Is there any advantage to a longer light brake vs a shorter harder brake assuming you never press hard enough to kick in the pads? Trying to figure out how to milk the recharge when I have choice of longer vs shorter stopping distance, or if it doesn't matter.

Click to expand...

Conventional 12V alternators have a regulated output as do the two motors that charge the HV traction battery. The liquid-cooled electronics stack that you see to the right of the engine is what does the regulating to and from the traction motor and from the motor/generator to the traction battery. This regulation is largely out of control of the user. We don't even get to control when the engine runs. . So the answer to your first question is no. The 2nd is no. The third is no. It may charge a little or a lot when idling depending on the SOC of the battery. As for maximizing regen, stay off the friction brakes as much as possible. The rules for getting great fuel economy out of the hybrid are largely the same as for a conventional drivetrain: be smooth. Stay out of turbo boost when accelerating and avoid braking as much as possible. Use the instantaneous fuel economy gauges to teach you how to drive.

Also, staying in EV mode as long as possible does not equal best fuel economy. It's much more complicated than that. Your car is a parallel hybrid rather than a series hybrid because under some loads and conditions it's more efficient to have the ICE drive the wheels directly. All the charge in your battery came from burning gasoline. (You could argue that some of the charge in the battery is regen but it was still gasoline that got the car going in the first place.) The energy in the battery has to go through a lot more conversions to power the wheels. My advice is don't try to 2nd guess the charging algorithm. You can try advanced hypermiling techniques like pulse & glide, drafting, and so on, but those take a lot of effort and are sometimes dangerous. Starting your engine and idling it warm in the winter is a terrible practice for fuel economy and for engine life. Use a block heater instead.

DailyD said:

Hey all, just got a Hybrid last week so time to join the forum instead of just stalking it.

I'm wondering a few things about the charging of the (not plugin) hybrid battery. My favorite light on the dash is the EV one! It's like a game for me to keep it electric as much as possible, and I'm consistently getting close to 40mpg.

On traditional vehicles, higher RPMs lead to higher charging rate of the 12v battery: Does gas engine RPM similarly effect the charge rate of the hybrid battery? As in could I strategically use lower gears to gain more charge? And does it charge much or at all when just idling (like if I use remote start in winter?)

Also, with regen braking... Is there any advantage to a longer light brake vs a shorter harder brake assuming you never press hard enough to kick in the pads? Trying to figure out how to milk the recharge when I have choice of longer vs shorter stopping distance, or if it doesn't matter.

Click to expand...

I agree with the above post.

The highest rate of charge I found is with the regen braking. You can actually see the SOC move quicker than the ICE can at any speed or mode.

Controlling the regen aggressiveness on a relatively fast but long braking like a down hill coast, moves the SOC pretty fast.

The algorithm used will make you batty trying to figure why it don't go into EV mode at times.

Quite complicated and alot of behind the scenes thinking going on.

I tried to out smart it, driving while getting the EV only mode on as much as I could. The balance of keeping the battery charged, not using the ICE, using EV as much as possible, coupled with road type and traffic trying to hyper mile, yielded great numbers.

They are only temporary and not a overall picture that is not sustainable or practical.

Nice to 50 or 60 or higher MPG, but really means nothing.

I just drive normal in the default ECO mode, and let the car do the thinking.

No issues getting around 38MPG as a average for me.