The Great Hybrid Battery Debate

Replying to: gagrice (Jul 24, 2004 4:34 pm)

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• gagrice (Jul 25, 2004 7:30 am)
  • usbseawolf2000 (Jul 25, 2004 7:16 pm)
    • gagrice (Jul 25, 2004 8:39 pm)
• eaa (Mar 22, 2006 7:42 pm)
  • imidazol97 (Mar 22, 2006 7:48 pm)

Replying to: john1701a (Jul 24, 2004 7:06 pm)

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• usbseawolf2000 (Jul 25, 2004 7:16 pm)
  • gagrice (Jul 25, 2004 8:39 pm)

Replying to: gagrice (Jul 25, 2004 7:30 am)

Becareful when someone use a general word "hybrid" since not all design were created equal. HSD can split power from ICE to generate electricity while climbing hills, assuming the hill is not steep enough to have spare power from the ICE.
 
04 Prius battery ECU will not let the battery discharge below 40% SOC. The rest of 60% of the 1.31 kWH battery can provide 28 hp for 135 seconds. If you climb the hill at 60mph and the hill is so steep that the battery provides all 28hp for 135 seconds, Prius can trouble 2.25 miles before the battery SOC get to 40%. It is when the turtle icon appears.
 
If the hill is not as steep and Prius main ECU request only 14hp from the battery, Prius can go up 4.5 mile long hill. That's a very long hill!
 
I know you had bad experience with batteries. Let me give you another graph which shows the Cylinder D-shape batteries(Used in Japanese Prius) and Prismatic batteries(Used in US Classic Prius). They tested over 180,000 miles for Cylinder and 150,000 miles for Prismatic. Note that 04 Prius batteries has less Internal Resistence than last generation Prismatic modules. Basically, these batteries can keep going and going and going .....
 

 
Dennis

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• gagrice (Jul 25, 2004 8:39 pm)

Replying to: usbseawolf2000 (Jul 25, 2004 7:16 pm)

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• john1701a (Jul 26, 2004 9:19 am)
  • stevedebi (Jul 26, 2004 1:24 pm)
    • john1701a (Jul 26, 2004 1:27 pm)
    • john1701a (Jul 26, 2004 1:36 pm)
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• usbseawolf2000 (Jul 26, 2004 1:41 pm)

Replying to: stevedebi (Jul 26, 2004 9:10 am)

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• stevedebi (Jul 26, 2004 1:24 pm)
  • john1701a (Jul 26, 2004 1:27 pm)
  • john1701a (Jul 26, 2004 1:36 pm)
  • usbseawolf2000 (Jul 26, 2004 1:47 pm)
    • gagrice (Jul 26, 2004 2:09 pm)

Replying to: john1701a (Jul 26, 2004 9:19 am)

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• john1701a (Jul 26, 2004 1:27 pm)
• john1701a (Jul 26, 2004 1:36 pm)
• usbseawolf2000 (Jul 26, 2004 1:47 pm)
  • gagrice (Jul 26, 2004 2:09 pm)

Replying to: stevedebi (Jul 26, 2004 1:24 pm)

Replying to: stevedebi (Jul 26, 2004 1:24 pm)

Replying to: stevedebi (Jul 26, 2004 9:10 am)

"No, the Prius doesn't push the envelope in battery technology; it just makes sure the batteries don't get over charged or fully depleted. Nothing new there."
 
Some hybrids like Civic Hybrid and Escape Hybrid are still using Cylindrical D-shape NiMH batteries. The graph I posted above shows that Internal Resistance is very high compare to the first generation of Prismatic NiMH. Second generation Prismatic used in 04 Prius is a couple of generation ahead of cylindrical model. See the inner working of both types and you might want to rethink about your "Nothing new there" comment.
 

 
This following information is for the first generation of Prismatic NiMH used in the classic Prius; from The Society of Automotive Engineers, written by Electric & Hybrid Vehicle Engineering Div. of Toyota Motor Corporation.
 
"The case is made of plastic, which was selected based on its resistance to the alkaline electrolyte, electrical insulation between cells, formability of the modular shape, weight, etc. The rectangular modules, when combined into a battery pack, reduced dead space and require a minimum amount of space for cooling. Thus, a compact package has been realized."
 
"To ensure electrical safety, the component parts of the high-voltage system are enclosed in the battery pack, ..... These parts consist of a system main relay (SMR) with a built-in current sensor, a service plug with a built-in fuse, and a battery electronic control unit (ECU)."
 
"It(SMR) functions(cuts off the high-voltage system) similarly when the vehicle is involved in a collision or when there is a malfunction in the system."
 
"The current sensor is used for calculating the state of charge (SOC) of the battery. "
 
"The fuse prevents electric shocks and fire in the vehicle when the battery short-circuits, such as in the case of a collision."
 
"Based on the current, voltage, and the temperature of the battery, the battery ECU calculates the SOC and transmits it to the vehicle control system. It also monitors the battery for abnormalities."
 
Information from Panasonic about 2nd gen Prismatic NiMH used in 04 Prius:
 
"High power battery module for HEV application (30% more power than conventional prismatic battery)
 
Newly developed battery has high power of 1300W/kg, 1.3 times higher than our conventional prismatic battery, and energy density of 46Wh/kg. By adopting new electrode materials and newly developed cell connection structure, internal resistance could be reduced, and more higher reliabilities on likely long life characteristic are improved due to the improvements of cell stack construction etc."
 
Dennis