Prius PHV: A toe in the pond before Tesla batteries?

The Prius PHV is obviously heavier than the non-PHV version, but you should take a look at the curb weights of other compact and medium sized cars for comparison.

2011 Altima 2.5: 3180 lbs (from 2011 Nissan Altima Sedan, Hybrid | Vehicle Specs | Nissan USA)
2011 NAH: 3470 lbs.
2011 Camry 2.5L w/6 AT: 3307 lbs (from Toyota Camry Performance & Specs)
2011 HyCam: 3680 lbs
2011 Honda Civic sedan: 2630-2831 lbs. (2011 Honda Civic Sedan - Specifications - Official Honda Web Site)
2011 Chevy Malibu: 3421 lbs (2011 Chevy Malibu Sedan Specs and Features | Chevrolet)

 

I was under the impression (like others responding to this thread) that the Prius PHV has batteries weighing 330lbs with total energy of 5.2kWh.
However, some figures do not match:
If each pack is only 1.73kWh, the two EV packs are 3.46kWh, but Toyota reports "battery charging power consumption" of 3.56kWh (a figure that was confirmed by several testers), how can you charge 3.56 into 3.46?
Furthermore, each pack contains 96 individual 3.6V cells in series for 345.6V total, if each pack is only 1.73kWh it gives only 5Ah for 110 lbs as compared to more than 6Ah for the NiMH battery of same weight in the Prius HEV! this does not make sense.

I now tend to believe that the 5.2kWh given by Toyota refers to the EV packs only weighing 220lbs (2.6kWh each). Since the main pack is identical to the EV packs, the total energy on board is 7.8kWh for 330lbs.

What do you think?

 

My guess is there are some loss from the charger. If it takes 3.56 kWh to charge 3.46 kWh, that's pretty efficient.

1.73 kWh / 110 lbs Lithium battery is better than 1.31 kWh / 99 lbs NiMh battery. There is a lot more room for improvement but this is just a prototype. I know it is unusually heavy for Lithium. I wonder if it holds some secret.

 

You have to keep in mind that because the Prius pack is so much smaller in capacity, they are asking each cell to work a LOT harder. To handle the increase in power requirements, the battery has to be formulated to handle extremely high charge/discharge rates or power density (kW / lb), which sacrifices energy density (kWh / lb).

For example, let's assume that your regular hybrid has a 1.8 kWh battery pack but has to be able to handle power draw/charges of 30 kW - that's a rate of over 15C (power over capacity = C - common term to describe charge/discharge rates).

A plug-in hybrid like the Prius PHEV has a bigger battery pack probably between 6-8 kWh in capacity but must also supply near full power - probably up to 60 kW, but the rate is only 7-10C so they can use higher energy density cells.

A EREV like the Volt has a 16 kWh pack but must handle even more power - 120 kW in it's case which means it's cells are probably similar in spec as the Prius.

An EV like the Leaf has a 24 kWh pack but only handles 90 kW - each cell has a relatively easy life of no more than 3C charge/discharge rates - meaning you can use very high energy density cells. The Tesla with a 53 kWh pack and a max power of 185 kW - the cells don't work too much harder than the Leaf cells at 3.5C max discharge rate, but then they monitor that battery a LOT closer, too.

Also, as you reduce the maximum charge/discharge rates on each cell, you can also safely use more and more of the available battery capacity.

The Leaf uses nearly all the available capacity. Plug-in hybrids use about 3/4. While a hybrid uses about half at most.

Anyway - I think that the plug-in Prius is on the right track. They are aiming for a market that's still not populated - short range plugin - and they should be able to keep the costs manageable. If they can keep the cost to appx a $3,000 premium over a regular Prius, they will have a winner that will make a significant dent in fuel consumption for most people.

 

Disagree.
If you have a battery with 3.46kWh total capacity, it will be foolish to try and charge it with 3.46kWh or anything near...surely you do not suggest a battery should be charged/discharged from 0% to 100% SOC.
Even if Toyota starts all of a sudden to be un-conservative and allows large "window of usable energy" like 65% that's still only 2.25kWh of charge.

 

Drees, you have a good point. PHV Prius' battery is more like a high power pack rather than Tesla's high energy pack.

giora, PHV Prius' pack has a total capacity of 5.2 kWh. If it charges 3.46 kWh, it is using ~70%.

 

Exactly, an affordable solution that almost everyone can benefit is the only realistic option for mass production. That will give the best bang for the buck which in turn will save the most petroleum consumption.

More EV range doesn't mean it is better. "More than electric" does not mean it is better. More <> Better.

 

Also, the energy consumption, as proven by testing, is lower than an EV with more range. Reasonable and lean, typical of the G21 project directives. Bravo, Toyota.
I can't avoid my personal belief that they were never wrong. Although we'd had to wait 15 long years to watch it bloom...

 

I would like to see a link or reference for that.

The loss may be 10% at most and that would be for 300 full charge cycles. (which I doubt)

Tesla allows for an 80% recharge mode (which most people should use unless they think they are going on a long trip) that has a much smaller impact on battery life even if you use most of the 80% charge.. Secondly with a 200+ mile range, you are almost never putting a full cycle on the battery.

Driving 15 miles on a 200+ mile battery does not count as a 'full cycle'.

 

This is where Toyota really shines.

Toyota has some of the most conservative battery designs. Certainly much better then Honda and in my opinion Nissan. I trust that battery life will not be a problem for the Prius PHV even eight years out.

 

The new 3.4 Ah laptop cells from Panasonic are supposed to be more reliable. Tesla is working closely with Panasonic to further increase the long life.

The cells used in PHV Prius are prismatic (rectangle) and it will not be high energy cells like laptop battery. It needs to be fairly high power and extremely durable (long life). Therefore, the trade off will be lower energy density. The result of PHV Prius prototype shows that it still has more energy than NiMH.

 

They give out conservative EV range too. Their range includes "hotel load". Nissan gave out the range from JC08 test cycle.

 

Easy answer. The 3 packs total 5.2kwh and 330lbs. You can't charge that without losses, and we don't know exactly how much the hybrid pack gets charged, but I would assume 3.56 of 5.2kwh.

Yep. We don't know the soc for hybrid pack versus ev, but if you do 3.56/5.2 you get 68% usable energy which is close to your 65%. Thinking that toyota's figure is charger efficiency is just not anywhere implied as one poster seemed to think.

By using 80% on the tesla, and using good liquid cooling, the life of the tesla battery should far outshine that 300 cycles, just as the prius 40% soc far outdoes the nimh that used to be in cell phones. But tesla's batteries were created by necessity.

LG, JCI-Saft, and NEC are now creating batteries for EV, PHEV, and HV that are shipping. All these companies have at least 2 Li chemistries with LG shipping in chevy and hyundai and speced in a ford, JCI-Saft in a ford ev and mercedes and bmw hv, and nec in nissan and infiniti. All the configurations seem designed to last a long time and warented as such. Toyota's design in the phv is much heavier/kwh and bulkier. Let us not pretend that the phv is shipping today, it won't be out until june of next year and the reason is the batteries are behind. Toyota may improve them by the time the phv ships, or at least get the chemistry to a point where they feel safe with a warranty as long as a normal prius. I'm optimistic that the final car will have a better battery than the test cars. Panasonic did buy sanyo for their lithium expertise after all, and we can hope some of those engineers are working on improved battery designs.

 

The ev range of the phv prius on the current epa test is actually 0. It is not conservative. Nissan used 100 versus 73 tested. Driving normally will turn the gasoline engine on, and there is not a mode to prevent this. The batteries will provide miles of ev range with bursts of gasoline usage.

 

I didn't know EPA tested it. Please show us the source of your information.

Toyota has been saying 13 miles.

InsideLine got 14.6 miles with PHV Prius while Volt got 33.9 miles under the same condition. For reference, Volt's EPA range is 35 miles but it was hyped to get 40 miles.

InsideLine data:

EV-mode electricity consumption (*kWh/100 miles) *unlike mpg, smaller is better:

Volt: 39.0
Prius PHV: 23.2

HV-mode (hybrid vehicle) gasoline fuel economy (mpg):

Volt: 31.1
Prius PHV: 47.2

EV-mode electric range (miles):

Volt: 33.9
Prius PHV: 14.6​

 

Did you even bother to think about what I wrote. The epa has now published their tests for ev range. The phv prius as it is in the test fleet does not qualify, since it uses gas in normal driving. It violates the test.

Toyota and the epa did not test it because A) toyota would not submit a car that would fail and B) there are no production phv prii.

Toyota has never said it would get any ev milage on an epa test. It has said that you will get 13 miles according to its testing, and if you accellerate harder than the software allows you will use gasoline. The 13 miles is not a conservative pure ev range. 0, the number on the epa test would be the conservative range.

Well that is just all mashed up isn't it. If the prius, leaf, and volt all were charged up and traveled 10 miles in normal driving conditions, two of the cars would not use gasoline, one of them would. If you were to repeat this in extreme conditons for 25 miles both the leaf and volt would not use gas but the phv prius would. I'm not quite sure what the data you provided says at all. The prius can go further on the same amount of gas than the volt and leaf if they don't have there batteries charged. For efficiency the volt batteries were doing a tougher test. You can not compare numbers, unless the volt only had to follow the phv prius, and the phv prius had to be driven without the engine firing up. I will be happy to ignore those numbers if you do that test though, because it simply does not matter.

 

You were the first to mention about EPA. Again, where is your source of information?

PHV Prius is already on the list of qualified vehicle for CA HOV lane. Unfortunately, the Volt didn't make it in there.

 

you commented on the link that evnow had on the foia. Did you not read the test procedure

http://www.smidgeindustriesltd.com/leaf/EPA/EPA_test_procedure_for_EVs-PHEVs-1-13-2011.pdf

http://www.fueleconomy.gov/feg/fe_test_schedules.shtml

Since the phv prius gasoline engine will come on early in the test, it won't not qualify for any EV range. EPA will use the gasoline and electricity used to compute a MPGe. The phv prius will have a different epa sticker than the volt since it does not qualify for EV range.

I do not see what the state of California has to do with conservative estimation of pure electric range. I no longer live in that state and find carb's rules quite counterproductive. For example the Honda accord is considered a advanced technology partial zero emissions vehicle, but does not even have auto start-stop. GM has stated that they will be at-pzev certified and flex fuel in 2012 with the 2013 my volt. GM's promise not mine. The phv has expected date to be shipping to texas, but toyota has said they will not ship in 2012. If you live in a carb state, I guess you are SOL with the phv prius or volt for carpool stickers until 2012. As the edmunds review indicated that you linked to, they prefered the volt but barely. You need to read the text to understand what those numbers mean, and if you drive 100 miles per day they talk about costs to operate.

 

Well, apparently there are some breaking news coming on. SAE J1711 will be different in Texas, just for Austingreen get his apple from the tree...LOL

quoting the draft previous linked...
"If the gasoline engine operates during the charge depleting mode, both the electric energy consumption and the gasoline
consumption are used to calculate the mpge values for the charge depleting (mostly electric) operation"

Caugh caugh

 

FYI: The PHV Prius is in "limited production", and has been since the 2010 model year. You can even pull parts lists and all service information from Techstream. They aren't selling units to the general public however.

Of course, they may change the specifications for the 2012 model year though!