My real-world experience with the PHV

Which is why we like Toyota so much. Doug is alright too....

 

Like many people, I'm sure, I'd also have no trouble using a long grade to fill up whatever battery capacity was available. It makes sense to me that the entire battery array could be charged fully by whatever means are available, but I don't know enough about it to say Toyota's doing it wrong.

 

Given what Tony just theorized, I wonder if the question is one of protecting the batteries. How many charge/discharge cycles can the current hybrid battery go through before you start noticing a capacity drop? Obviously a lot, especially with the sophisticated battery management they have in place. How many can the two lithium battery packs go through before you start to see a decline in capacity?

In changing the battery chemistry used, they have to understand the change in properties. Having the cells be non-rechargeable would help to extend battery life.

Just a thought... one I'm not to fond of, but a possibility none the less. I hope Toyota found a way around that problem with Lithium batteries

 

How many charge/discharge cycles can the current hybrid battery go through before you start noticing a capacity drop? ...............
The current NiMH cells manufactured by Panasonic are warranted by Toyota for up to 7 to 10 years depending on the geographical location.
Example, recharge daily x 8 years =2,920 times.
On the additional Plug in pack, if LiON is being use and if we have the specific type of LiOn cell used in the extra pack, will be easy to determine.
As a reference, A123 are expected to last at least 3000 charging cycles. These batteries are being manufactured in China. But Panasonic has been the supplier of choice for the Hybrid series of vehicles.

 

My thought is that the current setup will help keep initial cost down as there's less risk for Toyota:
- The heavily-used HEV pack is the tried-and-trusted NiMH
- The lithium batteries will be used a lot less than the NiMH: that should protect them and reduce warranty failures. An additional benefit of protecting the battery is that warranty failures are more obviously going to be due to problems with the battery instead of use.
- In case of failure they'll only have to replace a 1.5kW pack instead of 3kW.

In an accident it should also be easier to protect two smaller packs than one larger one.

I hope that it's a conscious choice instead of due to engineering difficulties.

 

Tony - have you been able to do one of your regular routes in HV mode only? I'm wondering what effect the extra weight of the batteries has on mpg when compared to a Gen 3 (or 2 in your case).

 

So the Plug-in achieved 71.5 mpg (Prius readout)...what would you expect from your 2004 Prius? (or did I miss that bit out of your post...apologies if so).

 

I hear you, but my perspective is I get on the freeway and have few techniques at my disposal, and the wind resistance quickly takes the day's EV charge. Done. Gone.

If I can force hybrid on the freeway, then EV all day around town in EV mode, I avoid multiple warm-up cycles. Use the ICE once instead of many times. An advantage of the MGs is low-end torque. That is irrelevant at freeway speeds, but huge in town.

 

i echo others here by thinking that we do not have a final product and the regen limitation for the traction batteries seems more odd than a mistake.

balancing the two packs would be the main issue i would think but i dont understand why regen would not be able to do that effectively.

now if regen can work as long as the EV batts were not "completely" depleted, then maybe you could simply turn them off before depletion if you knew you were coming to a long descent?

 

Presumably when the ICE first comes on to warm up it does not provide much power with much delayed ignition timing? Do you still have the ScanGauge to take a look at IGN?

 

No problem! Thanks for sharing your experience.

 

Can you cycle in and out of EV - hybrid mode like this:

• EV up a hill
• just before crest, hybrid mode to get gas to start
• hybrid down hill 'coasting' during warm-up
• when hill flattens go back into EV

What this does is let the warm-up proceed without a strain on the ICE. This will warm-it-up without the higher fuel consumption of a significant load. Then on the back-side of the hill, the engine should stay on (speed above 46 mph) and the warm-up continue at minimum fuel consumption. At the bottom when the fuel consumption starts to pick up, slide back into EV mode.

This is load driven, terrain driving at its best with the EV letting the ICE coast.

What I'd like to see would be a pre-hybrid mode threshold so before EV ended, the ICE would run but at idle. The reason is the time to warm the engine coolant does not change that much whether under load or not. So if the ICE is going to warm-up, use the least amount of fuel with an engine in idle.

It would be fascinating to see MG2 temperature during EV mode. If it gets significantly warm, it would be great if the engine coolant passed through the gallories to keep MG2 cool and bring the ICE closer to operating temperature.

Bob Wilson

 

I'm late to this party, but I'm happy for you Tony, I'm sure you are enjoying the opportunity for cutting edge experience and evaluation.

Honestly though? I think Toyota is being conservative in giving a Toyota Prius lover, a PHEV for only a week. A week is just long enough to fall in love but not long enough to really, really evaluate outside of the almost immediate impressions.

I suppose we are in virgin enough territory where immediate impressions based on a weeks worth of exposure are interesting and have some validity, but why not 6 weeks?

Hey, I'm just trying to buy you some more time....

 

conservative?? nah... just building up a little "want" in a potential customer i think