For those that got the Lithium Ion Battery

Who's selling this?

 

dr. prius, there are several threads here.

 

Mileage will vary depending on how well the engine is taken care of.

I know there is 10-12 mpg gain with it.
Increased EV mode mileage too.

I have tortured this battery by draining it, shorting it and even overcharging it beyond the standard system values.

This is not only lighter than the OEM or any other HV battery pack sold on the market currently.

Use the link below and save some cash.



http://www.RedBullet.net
Use code azusa

https://ProjectLithium.com/?ref=mG0GE

http://www.Pulstar.com

http://www.PlugOutPower.com
Use code 7373

http://www.HybridPit.com
Use code azusa

http://CatStrap.net
Use code azusa

QUOTES FOR FUEL GENIE SYSTEMS ON PRIUS CARS
Use code azusa

http://PriusOffRoad.com
Use code azusa

 

Cliff notes: Compared to a good NiMh battery I would not expect Li+ to show a measurable difference in highway fuel economy, but I could potentially see a 10-20% improvement in "city" fuel economy.

Best I can tell, the main benefits of Li+ are:

• 1.45 kWh total capacity (vs 1.31 kWh stock)
• 1.17 kWh usable capacity (vs 0.52 kWh stock)
• 260 Amps peak 3 second power (vs 150 amps peak 1 second power)
• 90-95% Li+ battery charge/discharge round trip efficiency vs 60-70% NiMh efficiency
• 40 lb battery weight vs 82 lb.

Increasing the battery's total capacity and the speed at which it can be charged/discharged will certainly improve the driving experience, but it won't do much to improve fuel economy because that energy still ultimately comes from the internal combustion engine. If you do a lot of long or hard braking, you might see a benefit from being able to recapture more regenerative energy, but that wouldn't be a factor for my driving style.

The 40 lb weight difference should translate to about a 1% improvement in rolling resistance for a 3,250 lb car. But by the time you're going 20mph, roughly 90% of your energy is already going to overcome aerodynamic drag so this tiny improvement in rolling resistance probably won't be noticeable unless you spend all day at parking lot speeds.

So that leaves Lithium ion's ~42% improvement in round-trip charging efficiency as the main potential benefit for fuel economy. If you spend all day driving steady speeds above 45mph, this is going to be of zero benefit to you because the engine will be running the whole time. If you spend a lot of time "idling" your Prius, then you could potentially see a ~42% improvement when running off the battery. So those who do a lot of stop & go driving or camp in their Priuses might see a significant benefit - perhaps as much as 10-20%.

Using the more optimistic guess of 20% improvement, a stop & go driver who always runs the A/C might go from say 45 mpg to 54 mpg. That's about 56 gallons a year for someone who drives 15,000 miles. At $5/gal it would take that driver about 7 years to repay the "upgrade" to lithium ion. Of course if your NiMh battery is going bad and you're already looking at paying $2000, then cost probably isn't a factor.

The other big downside is recommended storage temperature:

Dr Prius:
15-35 C (59 to 95 F) recommended, -10 - 45 C (14-113 F) storage

NiMh:
-20-35 C (-4 to 95 F) recommended, -20 - 45 C (-4 to 113 F) storage

 

@johnnychimpo

Many on here that bought it have zero complaints and do notice the improvement with it installed.

Join the rest of the crowd that has a Red Bullet and enjoy the prius even more!

 

VVT Solenoid- Red Bullet or Bull@*$% ? | PriusChat

Stuff like this rarely has a reasonable payback period

 

One correction: Assuming CD = 0.25, m = 1480 kg, A = 2.22 m^2, and CRR = 0.010, aero drag and rolling resistance drag will be equal around 45 mph, and you won't reach 90% energy expended to overcome aero drag until a speed well above that, around 137 mph.

 

Doh, you're right - I was using a bicycle CdA. Here are mpg estimates with 0.008 Crr, .25 Cd, 24 ft^2 FA, 35% thermodynamic efficiency, 75% drivetrain efficiency:


MPH MPG(3340 lb) MPG(3300 lb)
5 ...... 160.58 ............ 162.5
10 ..... 154.04 ............ 155.81
15 ..... 144.25 ............ 145.8
20 ..... 132.47 ............ 133.77
25 ..... 119.87 ............ 120.94
30 ..... 107.4 .............. 108.25
35 ..... 95.63 ............... 96.31
40 ..... 84.9 ................. 85.44
45 ..... 75.32 ................ 75.74
50 ..... 66.89 ............... 67.22
55 ..... 59.52 .............. 59.78
60 ..... 53.12 .............. 53.32
65 ..... 47.55 .............. 47.72
70 ..... 42.72 .............. 42.85
75 ..... 38.52 .............. 38.62
80 ..... 34.85 .............. 34.94
85 ..... 31.64 .............. 31.72
90 ..... 28.83 .............. 28.89
95 ..... 26.35 .............. 26.4
100 ... 24.16 .............. 24.21

Unfortunately real-world engine & drivetrain efficiency will vary with speed/rpm/load so actual mpg numbers will deviate (especially at low speeds when engine/battery losses are higher). But it gives you an idea of how much difference 40 lbs might make at various speeds.