If you have a question that's not answered here, please check out the EDrive PHEV listserv at groups.yahoo.com/group/EDrivePHEVQuestions posted to the listserv will be answered there and may eventually show up on future versions of this F.A.Q.

The main question : When will EDrive become available for sale?
We have finally concluded technical development and testing of the all-new next-generation EDrive system. We will be making first deliveries to fleets beginning in August, and expect to begin retailing the system before the end of the summer.

1: Why plug-in hybrids (PHEVs)?
With gasoline approaching $5.00 per gallon, increasing fuel economy is a priority. The EDrive PHEV system, at a minimum, doubles the Prius fuel economy for roughly 40 miles by adding electricity from a conventional 110V outlet, electricity that costs approximately 25% of the energy equivalent of the gasoline it displaces.

2: Doesn't plugging in the car just trade oil pollution for coal pollution?
Californians are spoiled by one of the cleanest electrical grids in the U.S., but even where coal supplies much of the electrical power, plugging in vehicles is still a smart environmental solution. One thing that is often overlooked when electric power plant pollution is discussed, is the upstream pollution required to extract oil, transport it, refine it, distribute the gasoline then refuel a vehicle (vapor emissions). Comparing the national electrical grid to the average gallon of refined gasoline shows that the upstream pollution for gasoline production on average is much higher than that of the average electricity source.

Plug in vehicles charge at night when electricity is cheapest and most widely available on the grid. While electricity may be produced by renewable or non-CO2 producing sources, fossil fuels at present cannot.

3: What is the EDrive system for the Toyota Prius and how does it work?
The EDrive system replaces the existing Prius NiMH battery and Toyota battery control computer with a larger advanced lithium-ion battery and a proprietary battery monitoring and control system. The new system allows the Prius to be charged at home using a standard 110/120V home outlet. With the larger battery, the Prius runs in electric only 'EV' mode at lower speeds or when less power is needed. The result is EV driving and electrically boosted gasoline driving for the first 40 or so miles with a gasoline efficiency of over 100mpg. After the 40 mile 'boosted' range, the vehicle performs just like a standard Prius until it is plugged in again. The battery system is about 2" higher and 3" longer than the Toyota NiMH battery. It is installed under the rear cargo carpet without limiting access to the spare tire. A small display is mounted on the dashboard.

4: What is the driving experience like with an EDrive equipped Prius?
After the nightly re-charge, the vehicle can be driven in EV mode until the vehicle speed exceeds 34mph. At this point the engine may start in order to warm up the emission control system. After the emission system is warmed up, the Prius will use the gasoline engine whenever higher speeds or power levels are needed, but will always (for the first 40 or so miles) inject electricity to reduce gasoline consumption. It is possible to drive in EV mode at speeds over 34mph and up to 55mph if the power requirements are low enough. The dashboard mounted display will always tell you if you are using gasoline and if not, how far you can press the accelerator without turning the gasoline engine on. In low speed city driving and 55mph freeway driving it is possible to average over 200mpg. More aggressive driving over 65mph will lower the efficiency to 100mpg or less. For example, 75mph freeway driving could result in less than 80mpg.

5: Why the big difference between 55mph and 75mph?
Because of the configuration of the Prius, electric use is limited to 21kW and often less. At speeds over 34mph, the electrical contribution is more or less constant. You may find at 55mph that 1/4 of the power is coming from gasoline and 3/4 from electricity, but at 75mph the contribution may be 2/3rd gas and 1/3rd electric. Even though the electric contribution is the same in both cases, the gasoline contribution (and thus mpg) can be dramatically different.

6: Can I really get over 200mpg with EDrive on my Prius?
Yes, but it requires low speeds (55mph freeway) and mild acceleration in city driving. Most Prius EDrive users will likely get closer to 100mpg.

7. How long does it take to charge?
The EDrive lithium battery system is 7.2kWh or kilowatt-hours (the Prius NiMH battery is 1.3 kWh). The charger used by the EDrive system is 1 kilowatt (kw), about the same as a hair dryer. If the battery were totally depleted, it could take 6 hours (6hrs * 1kW = 6kWh) to charge the battery.

8. Can the charger work on 240V power as well?
Yes, but the charge speed will be the same (1kW).

9. What is the EV driving range?
If you were to limit your speed to less than 34mph, the gas engine may not come on for over 30 miles.

10. How much does it cost to charge the car?
A full charge could take up to 6kWh of electricity from the wall socket, but on days when the car is driven less than 40 miles, the electricity needed to re-charge will be less. If your electricity cost $0.10/kWh (about average) then a full charge would be just under a dollar.

11. What happens if I forget to plug in the car?
Then the vehicle will behave exactly like a normal Toyota Prius. (ie ~50mpg)

12. Is fast charging available? Can I use public EV charging spaces?
The EDrive system was designed for only a 1kW charger with the intent of being slow charged at night when spare electricity is most available on the grid. Unlike an electric vehicle that might need additional charging during the day, a plug-in hybrid can still be driven as a gasoline hybrid after the battery is depleted (40 miles into the day). EDrive is not planning to offer higher speed charging as it shouldn't be needed and would only increase the system cost.

13. Can more batteries be added to increase the electric/boost range?
EDrive was designed for 40 miles of boost as this was just beyond the average daily mileage for drivers. Ideally the battery should be sized in order to balance utilization, cost and battery life. At 40 miles boost range, there will be many days when the battery is only 1/2 or 2/3rds used, which will greatly increase battery life.

14. How safe are the advanced lithium-ion batteries?
The advanced lithium iron phosphate battery system developed by EDrive has been designed with safety as a primary goal. Multiple innovating technologies spanning safe electrochemistry, electronics, software and cell packaging have been developed to assure maximum safety and longevity for the battery system. Safety and long life are primary concerns for vehicle applications.

15. How long will the lithium-ion battery last?
Testing indicates that the batteries should last over 5 years in an EDrive equipped Prius, with 10 or more years being possible. Depending on how the 'end of life' is defined, the battery may last the life of the vehicle (i.e. if 25 miles of boost range is deemed sufficient from a system that initially provided over 40)

14. How much does the EDrive battery weigh?
The EDrive battery pack weighs approximately 200lbs. The Toyota NiMH battery removed from the vehicle weighs approximately 80 lbs. The net weight increase is thus approximately 120lbs.

15. What happens to the existing NiMH Prius hybrid battery?
It is removed during the EDrive system installation process.

16. Does the EDrive system affect any other part of the Prius (like the AC)?
Many of the Prius subsystems (such as AC) are already electric. The Prius was designed to have electric driving modes, EDrive merely enhances the existing system.

17. How safe is the EDrive option?
The EDrive system is designed with safety in mind. The advanced lithium iron phosphate battery system provides exceptional safety and the rear battery pack is designed to be well away from the rear crumple zone in the event of a read-end collision.

18. When can I get EDrive installed in my 2004-2008 Prius?
First deliveries will occur in August 2008.

19. Where can I get EDrive installed in my 2004/05 Prius?
Initially, all installations will be done at Clean-tech in Los Angeles.

20. Will it be available outside of California? When?
As far as the U.S. market is concerned, we are concentrating on Southern California first. Within 9 months of the initial sales in L.A., additional authorized retail/installation locations will be set up in other parts of the country.

21. How long does it take to install EDrive in a Prius?
About 4 hours

22. How much will the EDrive conversion cost?
$12,000, installed.

23. Is EDrive available as a user-installed kit?
No. Only EDrive certified and trained installers will be installing systems. The installation involves working with high voltage and sensitive electronics which require specialized training.

24. How does this affect my Toyota warranty?
If a warranty claim were disputed by Toyota, Toyota would be responsible to show how the modification caused the problem. As the EDrive system never touches anything under the hood of the car (engine, motors, hybrid controller etc) it is not clear how this would be handled. Fortunately being a Toyota product, the Prius has shown to be an extremely reliable vehicle and we don't anticipate any changes in reliability with the EDrive system installed.

25. What will be the warranty on the EDrive system?
The basic included warranty is expected to be 3 years/36,000 miles. We have different warranty and service packages available.

26. Will EDrive work on Honda hybrids?
While it may be possible to inject some electrical energy into the Honda IMA system, because the Honda motors and battery system are less powerful than the Toyota Hybrid Synergy Drive system and offer almost no EV mode capability, the performance improvement from plugging in would probably be lower.

27. Will EDrive work on pre-2004 model Prius vehicles?
There are no plans at this time to offer EDrive for pre-2004 Prius.

28. What other hybrids will EDrive be available for? When?
There are no plans at this time to offer EDrive for vehicles other than the Prius.

29. Can EDrive be installed on non-hybrid vehicles?
No

30. Is there any way to add solar panels to the Prius to charge the EDrive system?
Yes, but we don't provide such a system and it may only provide a negligible benefit.