Several demonstrators of the PHV reported (surprisingly constant) plug-in charge of 3.6 to 3.66 kWh after complete depletion of EV batteries. Lets take an avrage of 3.63 kWh. Assuming charging is 85% efficient, this calculates to 3.09 kWh net energy. We know that each battery capacity is 1.73 kWh. Assuming the usable energy window allowed by Toyota for the HV battery is 40% (similar to the HEV), and assuming that at the end of normal driving 75% of this 40% is left in the battery, then .17 kWh is charged into the HV battery during plug-in (.25 x .4 x 1.73), and 2.92 kWh (3.09-.17) is charged into the two EV batteries. 2.92 kWh for 14 miles - this is 209Wh/mi net or 245Wh/mi at the wall socket, allowing 15% losses. This 245Wh/mi at the socket does not change if the charging efficiency is 90% or 80% instead of 85%. This calculation also gives 84% usable energy window in the EV batteries (2.92 vs. 3.46) for charging efficiecy of 85%, this seems high. (in case of only 80% charging efficiecy, the usable window calculates to 79%). What do you think? Giora. P.S How do I edit the typing mistake in the subject?? Anyway, its our new year eve today 8 September.
Charge/discharge efficiency for Lithium-ion polymer battery is quoted at 99.8%. en.wikipedia.org/wiki/Lithium-ion_polymer_battery I'd say we're talking of 261 Wh/mi priuschat.com/forums/prius-hybrid-news/82885-dr-rangelove-how-i-learned-stop-pumping-love-plug-4.html#post1178564 Happy New Year should i say?
Energy Consumption should be related to plug total delivery divided by miles travelled, as per EPA or other legal ou practical point of view. 3.63 KWh / 14 mi = 259 Wh/mi Effective energy consumptions are another calculated value, somewhere in the middle of the drivetrain consisting of: Plug -> Batt (99,8% seems too high - please follow chart [ame]http://en.wikipedia.org/wiki/Rechargeable_battery[/ame] ) SOC lost due to time if applicable (NiMH loses more than Li-ion) Batt -> MG -> wheels (95% or more)
Define efficiency. I believe the 99.8% you are eferring to should be called 'reversibility' i.e. how reversible is the process, in other words - how much of the original capacity left after every charge. I am speaking of the efficiency of the charging process itself i.e. how much we loose as heat in the contacts, cable, chargers etc. and in the battery during charge. Thanks for the greeting.
Acturally, you start from the right, and go left, thusly ... according to my wife's Grandma Gold: ראש השנה שמח .
