Why no hybrid trucks yet?

[S Keith]

Originally Posted by ksa8907

Do you have first hand experience? We have a 2012 and haven't had any issues with it the last 40k+miles we've had it. Anything I should be looking out for? I believe these use Toyota Prius battery NiMH cells.

I have personally tested 3 of them. All were completely destroyed though normal use. I've assisted a dozen people remotely by processing their battery data captured through Torque Pro.

I'm also on a first name basis with someone who has intimate knowledge of the design of the GM hybrids, and some of the issues they had between their own decisions and issues with the pack as produced by Toyota/Panasonic.

The criteria for battery failure are such that the battery is completely ragged out by the time it registers a failure.

The battery is completely abused by excessive current primarily due to the high torque load at "launch" coupled with the spin-up of the big V8. The Prius limits the same components to 150A in rare cases. The GM will pull 220A+ routinely if romped.

Their cooling system is completely ineffective.

Here are your options:

1. Gentle launches. Don't romp until the V8 is already spinning and can provide torque.
2. Drive conservatively.
3. Keep the interior as cool as possible during moderate to hot weather.
4. Avoid use of recirculation while cooling. It can create a vacuum in the cabin and reduce the battery's ability to eject warm air.

[ksa8907]

Originally Posted by redpoint5

Right, I know there are purpose built inverters for local storage, but that's not what we've got because we had no intention of spending money on a battery system (it's not worth the investment unless it can offset peak rates, and we don't have TOU pricing here).

What's missing to make it capable of being tied to a battery instead of grid? Probably not worth the engineering effort, but it's a shame to spend another $3k to get a different one that is designed to feed a battery.

I'll research this some more, but like all inquiries that involve "off-label" use of a product, the internet mob will revolt for even considering an unconventional approach.

I missed the part where you already have one. Not sure the solution, I'm sure there is one.

[ksa8907]

Originally Posted by S Keith

I have personally tested 3 of them. All were completely destroyed though normal use. I've assisted a dozen people remotely by processing their battery data captured through Torque Pro.

I'm also on a first name basis with someone who has intimate knowledge of the design of the GM hybrids, and some of the issues they had between their own decisions and issues with the pack as produced by Toyota/Panasonic.

The criteria for battery failure are such that the battery is completely ragged out by the time it registers a failure.

The battery is completely abused by excessive current primarily due to the high torque load at "launch" coupled with the spin-up of the big V8. The Prius limits the same components to 150A in rare cases. The GM will pull 220A+ routinely if romped.

Their cooling system is completely ineffective.

Here are your options:

1. Gentle launches. Don't romp until the V8 is already spinning and can provide torque.
2. Drive conservatively.
3. Keep the interior as cool as possible during moderate to hot weather.
4. Avoid use of recirculation while cooling. It can create a vacuum in the cabin and reduce the battery's ability to eject warm air.

Thanks for that, I really was surprised how how inadequate the "cooling" system is in this setup. We generally don't race it around, the way we drive it it's a little slow off the line then when the engine comes on we push it a bit harder.

If you don't mind, what is a good way to evaluate the battery? I saw some of your posts over on greenhybrid. Our battery will drive us around parking lots and let the a/c run for a few minutes in summer.

I'm sure it's not in great health but hopefully not on its last leg. It strikes me as a really good stop/start system more than a hybrid.... hopefully that's not already indicative of a trashed battery.

[S Keith]

Originally Posted by ksa8907

Thanks for that, I really was surprised how how inadequate the "cooling" system is in this setup. We generally don't race it around, the way we drive it it's a little slow off the line then when the engine comes on we push it a bit harder.

If you don't mind, what is a good way to evaluate the battery? I saw some of your posts over on greenhybrid. Our battery will drive us around parking lots and let the a/c run for a few minutes in summer.

I'm sure it's not in great health but hopefully not on its last leg. It strikes me as a really good stop/start system more than a hybrid.... hopefully that's not already indicative of a trashed battery.

https://www.greenhybrid.com/forums/f...results-31736/

[Ecky]

Originally Posted by redpoint5

There's some point between the size of a sedan and the size of a locomotive that a series design begins to make sense. Full-sized pickup trucks with 10 speed transmissions may benefit.

Don't those enormous mining dump trucks use a series configuration?

Honda's hybrid system is a fair compromise. Part of it might be just avoiding Toyota's patents, but in all new Honda hybrids, they're strictly "series" hybrids up to ~60mph, at which point the engine is clutched to a single speed reduction gear, allowing it to drive the wheels directly. It's light, compact, and efficient under most real world conditions.

In theory a planetary gearset allowing the engine to directly power the wheels at any speed is more efficient, but due to cost/complexity/size/weight I don't think the jury is out yet.

[ksa8907]

Originally Posted by S Keith

https://www.greenhybrid.com/forums/f...results-31736/

I made a post there with my data, care to let me know your thoughts?

[S Keith]

Originally Posted by ksa8907

I made a post there with my data, care to let me know your thoughts?

Looks great.

Your driving style and potentially a milder climate is helping.

Concerning the start-stop nature of the system, note that if you are requesting heat from the HVAC, the only source is the engine, so it will run more often. When heat or A/C is not needed, that's when it performs the best.

It's also not an EV in any way. It's purely an energy storage and release system to supplement the vehicle when it's operating at its most INefficient phases on gas.

Consider that the USABLE energy in the HV battery is about the same as the TOTAL energy in the 12V battery under the hood.

HV battery is 1.87kWh. 40% of which is usable, so 0.75kWh.

I don't know the specific capacity of your 12V, but I would expect it to be at least 60Ah. 60Ah * 12V = 0.72kWh.

You wouldn't expect to be able to drive around on the 12V battery in EV mode for very long. Same is true of the HV battery.

Lastly, in almost all circumstances, efforts to force or encourage EV mode are always a false economy. Anything extracted in EV mode will have to be replaced with gas. Creeping around a parking lot is fine. Trying to force EV mode on surface/residential streets is counterproductive. Just drive conservatively, and you'll get the best mpg and battery life.

[cRiPpLe_rOoStEr]

Originally Posted by JSH

Drivers are conditioned to expect RPMs to rise during acceleration and then drop at the upshift. Rise and fall, rise and fall, rise and fall. When a CVT goes to peak torque or HP and just stays there it seems odd - like the engine is screaming and being abused. Of course it isn't but goes against decades of tradition.

This might be among the reasons why the Prius doesn't feature a tachometer

[redpoint5]

Tach is a bit pointless when it cannot be controlled. I've seen manual transmission vehicles without a tach and wondered why it was omitted.

The Prius isn't just sans tach, but also sans temperature gauge. Idiot lights only.

[cRiPpLe_rOoStEr]

Originally Posted by redpoint5

I've seen manual transmission vehicles without a tach and wondered why it was omitted.

Blame it on the bean-counters. On a sidenote, I learned to drive on a car with manual transmission and no tach, so actually took me a while to get used to keep an eye on the tach once I became more used to it