Dear Forum, My name is Alex and I work for an autobody shop. We have a prius in that needs a new battery. The main battery was removed before we received the car on a trailer. The body is repaired and ready to go, but we are unfamiliar with hybrids. We have to drive the car to a toyota dealership for a new battery installation. Can we start the car and drive normally with only the gas engine? For future reference because i am interested, can you drive it without the electric assist? Will it function on reduced gas engine power or anything like that if you drive without the main battery? Will it still turn off at stop lights? Thanks alot. -Alex
the main battery is used to power the electric motor to spin up the gasoline engine, there is no starter. Therefore you need the main battery hooked up in order to start the vehicle, it cannot be driven without it. If the charge is depleted below 40 % SOC the vehicle will not start. its fairly easy to hook it up you know, unless your missing parts, if the case and everything is on the battery you can bolt it on and hook up the two wires and plug in the ECU, its fairly simple. The voltage is isolated as long as the battery case is not off. If you cant install battery you will need a tow to the dealer
Judging by your unfamiliarity of how the Prius works I strongly discourage you from trying to install the new battery yourself. It's high voltage and though not a mechanically difficult task to accomplish if done wrong could lead to your death or serious damage to the car. Just put it on a flat-bed and drive it to the dealer...they'll need to do some testing with their scan tool anyway and you can let them risk death instead of you!
Now, hold on a sec. This is an excellent learning opportunity for an independent, and we know how important that is. If you have time, check out some of the training resources kicking around on the net -- my slides, autoshop101, the Emergency Response guides at Toyota... all of these can help you be both safe and confident on hybrids, and I'd much rather see you grab this chance than just give up and push it into Toyota's bay! [And believe us, there are a few "hybrid qualified" guys over there you wouldn't want muckin' around back there either -- you get all kinds, as in any field.] . Where are you out of? This is making me wonder how convenient it would be to stop by and make a new friend.. . _H*
The disassembly it the easy part. It's getting all the pieces back together that takes some doing, and no, having a few left over is not a good thing. Tom
Unless the battery is damaged somehow, it would be VERY difficult to get a shock from it. It's disconnected -inside- the metal box by a relay. The internal connection is made by a relay. Any short of either power lead to ground will shut it down. The relay is only closed if the onboard computers are happy when you try to start the car (foot on brake pedal, you press "ON"). Toyota didn't want mechanics to be getting shocks or electrocution. It's bad for business. The duplex outlet on the wall is more dangerous!
gotta take it in... i thought you had to use scantool after battery replacement because car will recognize the change and have to be "calibrated" for the new battery...maybe wrong but i seem to remember... where is galaxee when you need her ??
Thanks Thanks, I guess we will probably just load it on a flatbed and take it to the dealer. What happens in a prius if you are driving down the road, the gasoline engine on, and the main battery fails, doesnt charge, disconects, ect. Does the car just stop or is there some kind of "limp home" mode.
yes it does limp home... the gas engine while ok at highway speeds, has very little torque so acceleration from a standing start will be very very sluggish. a few here that have had battery failures describe it as like driving with the parking brake on
As Dave says, and if you succeed in stalling the ICE you wouldn't be able to restart it if the traction battery (the high voltage one) was not functioning. The car would shut off if the battery was getting really hot, or some other safety thing was happening. The traction battery is used as part of "normal operation", so it's difficult to operate the car without it. For example, the power steering runs off the high voltage system as well as the air conditioning. The brakes, computers, and lights run off the 12V system, but it is charged by the high voltage system, so you could rapidly run the 12V battery down as well. I'm not sure what safety subroutines you would trigger (the car is run by computers, more so than any other car I'm aware of). Whatever, the car would not be happy without the high voltage systems working properly.
Not only is it difficult to run the car w/o the HV battery, it is impossible. The entire HSD is integral to the operation of the car.
Yes, but he asked what would happen if the battery failed while you were driving. So I speculated on that. As I said, if the ICE stalled for any reason you would then be "dead in the water".
you said the battery is missing, by that I assume that your saying that you have a battery connector on the end of a wire harness coming in to the rear compartement. If so you need more than the battery. There is a control module and relay set and numerous other pieces inside the battery case that will need to be supplied as well. Unless you have all the pieces it's probably a better bet to get a used battery complete with all the components inside the case.
it is impossible to start the vehicle without HV battery, a MAIN battery warning will be illuminated on the MFD. http://www.geocities.com/cscchybrid/PICT1312.JPG 01 prius
