4th generation coming 2015!

I don't have much familiarity with Lithium Ion batteries, but I am very familiar with Lithium Polymer batteries, which are closely related. I fly remote control airplanes using LiPo batteries. I've probably have at least 100 different LiPo batteries, all the way from tiny one cell ones up to 6 cell, 7700 ma LiPos that I run together in series (12 cell) to fly a 30 lbs, 100cc plane.

Based on my experience with LiPo batteries, I would not buy a car that uses a Lithium battery. For my planes I buy top of the line batteries (my largest cost $800 for a pair and is advertised to last "up to" 600 cycles), and I still don't get many cycles before having to replace them. I baby my batteries, always leaving at least 20% capacity on discharge, never leave them fully charged (that really shortens battery life) and only charge them at a slow rate (1 C).

If I am really lucky I will get 200 cycles before the lipo isn't worth using. Often I only get 100 cycles, or less because the battery puffs for unknown reasons. Even if I do get 200 cycles on a good battery, long before that I will notice a loss of performance (less capacity, higher resistance, less power).

Maybe Lithium Ion lasts much longer than Lithium Polymer. But I think the drawbacks are the same, if not as pronounced. The only reason we use LiPo batteries in our hobby instead of Nimh is because of weight, we can't afford the extra approximately 50% that Nimh would weigh. The battery in one of my larger planes makes up 20 to 25% of the total ready to fly weight. I don't know what a Prius battery weighs, but I would guess it is well under 10% of the total weight (maybe 5%?), not enough that Lithium will make a big difference.

 

NiMH isn't 50% heavier than LiPo, it's more like 150%.

A Prius Nimh battery is under 3% of the weight of the car.

Our LiPo's die early because we abuse them by discharging them at 10-30C and by charging them to 100%. Charge them to 80% and keep discharge to 1-2C and they'll last many times longer.

 

Right, and while charging and discharging keeping the temp even keel like tesla gas learned to do.



I thought Toyota actually approached tesla about making LiIon batteries for them "Toyota"?

 

Are you thinking of the RAV EV ?

 

Can't remember.. Just rings a bell, was a few years back

 

Yes it was the Rav EV. Tesla helped engineer it and I think even put their engine in there for Toyota.

As for Li-Ion batteries, again - Tesla wouldn't be investing 100s of millions if Li-IONs were bad as mentioned (and if software couldn't regulate them or if they caught fire, etc...) Remember, the Roadster is older than the Volt and PiP so there is a good amount of data regarding long lifespan of Li-Ion.

Unfortunately the bad reps are as follows:
- Leaf in hot weather degrading badly because apparently the batteries don't cool well (I'll be curious on how NiMH fairs in Arizona)
- Fires from Li-Ion crashes (from Tesla, of course gasoline catches fire too and I heard the Tesla will actually give you time and a warning if it detects something wrong)

 

Well you can't have bottlenecks or you will produce heat that transfers everywhere and degrades on all levels everywhere.

Lots of current moving back and forth... Tesla liquid cools the batteries "or heats".

They've blown millions figuring it out, might as well take cues from them.

 

Certainly note a technical review, but I just spent 2 1/2 weeks in the Nevada desert where the daytime temperature was between 110-114, and the night temperature was 94-100. I drove my 2010 every day in stop and go city driving as well as highway speed, and the battery never made it's presence known. I did not even hear/feel the fan (right rear seat).

In all fairness, I must acknowledge that I am a NiMH supporter ..... I just do not know how a motorist could expect more from a battery year after year, mile after mile with absolutely zero issues. If I was not a PC reader, I would not even be aware there is a HV battery or where it is located ..... I've never seen it.

 

They are a winner for sure, but you have to shave away 60 percent of their capacity to give them that reliability.

If you've used LiIon power tools or even a modern cell phone, you'll know nimh of yesterday has gross limitations.

LiIon has evolved do far now, it's a no brainer which is best... Cost is the consideration.

The average Joe only looks at cost verses payback... It's amazing some ever bought hybrid at all...

 

Well, looks like we finally have confirmation that 2015 is a carryover model:

2015 Prius Persona Special Edition Info, Changes & Photos | PriusChat

Obviously they wouldn't announce a new persona series if the non-persona was getting a complete redesign. I'm not holding my breath for any announcements until January-February of 2015.

 

Come on, they can still show a prototype model of the new Prius at the LA show Yeah the persona is like a throw-our-hats-in deal without making a big deal, trying to milk every last thing they can from the Prius. But I remember the last persona series and I don't think it was a big deal

 

Interesting, I just spent a week there too - between Ely, Eurika, Austin, and Cortez. Not too different from Arizona, except that the ground water was hotter in NV.

Tire quality and ground clearance are the top 2 vehicle requirements out there for me.

If you had a gen II, you'd know all about the battery if you ever drove in a hilly region. The battery would deplete and you'd lose significant HP as the electric motors would not get powered - especially dangerous if you are passing someone and the battery depletes and now you can't pass them. I'm surprised there weren't accident fatalities due to this.

 

If they delay long enough, I'll be able to consider a Tesla Model X along with the PiP. Maybe the model S will come down in price by then too?

 

mozdzen - I don't doubt what you say, but the discussion is not about pre 2010 batteries. If history is the criteria, I had a frigaking a/c in a VW that would retard the vehicle on level ground when the compressor came on. With over 97,000 miles on my 2010, and 5 cross-country trips, I have never had the battery deplete or loose "significant HP." By 2010, Toyota had those problems solved.

BTW, I agree with you about ground clearance. Alas, I have just conceded that a Prius is not going to be a good off-road car, neither a gravel road, or a snow rutted road. But I love the fuel efficiency on hard surfaced roads.

I am really disappointed that Toyota had to postpone the G4. But I am grateful they did IF the kinks had not been solved. Nothing would be worse than to market a problem prone vehicle, problems that Consumer Report (as well as automotive magazines) would report, and label "The worst car of 2015" or "Cars to avoid."

 

Your right about that... We all want it now but will quickly crucify them if anything is wrong... I do appreciate excellence... We are all too busy to make monthly trips to the dealers and Toyota can't afford it because the dealers milk it when that happens.

 

Take pity on me.

You are = You're

 

Sounds the same to me?

I'm from the south.. Thought I was doing pretty good!

My phone often writes what it wants unless I correct it, especially using Text-to-Speech.

You don't correct people when they talk to do you?

 

Yep.

Homophones are words that sound the same but have different meanings.

 

The software is drastically different. In Gen III, the battery is transparent, it is never allowed to discharge to the point of losing the electric motor. Not so in Gen II.