Would one ever need to jump start a Prius?

[happy]

This is a weird question, I'm sorry, for anyone clever with cars.

I was transferring stuff I normally carry  around into my "new" car, and came upon the jumper leads, which I have carried in my car for decades.

But then I wondered if there was a need with a Prius?

I was told If I ran out of petrol, I had about 5km of battery, and then the car would shut down and be very difficult to bring back to life (ie need towing). On thinking further, since the thing is designed to keep charging up the battery, I imagine you would not ever get a flat battery (unless the battery itself was dying). Hence my question.


Also could I jump start another car with my Prius using regular jumper leads? (suppose I should check under the hood to see if I can even see a battery to connect to)

[Half-Borg]

I found some source explaining how jump starting a prius works http://www.priuswiki.de/index.php?title=Starthilfe.
All german so I'll translate it:
The Prius has a support system running on 12V, with a very small battery. That system powers your control units. So if this support battery is dead, you can not start your prius, no matter how much energy is left in the traction battery. It can be jump started using just like a regular car, this will not necessarily start the engine, but will allow to boot the inverter, which in turn can power the 12V system from the traction battery. So you do not need much current. You can even use a scooter for jump starting. Do not turn off your hybrid system for at least an hour, to reload your support battery.

It does not say anything about a low traction battery, I guess if your traction battery is dead, you are pretty much screwed, you might need a new one anyway.

You can also jumpstart another car with your prius, you just need to be aware that it is powered from the inverter and your support battery, not from your engine, so you might want to wait a couple of minutes before you retry.

[happy]

Danke schon (sorry can't find the umlaut).

Very interesting. It has 3 modes of operation and switches between the traction battery and the petrol engine: on a hot day if the air con is on (like today 37C) and you are stationary for any length of time, the traction battery will gradually drain and the engine switches on to keep it charged.

I'm wondering if you ran out of petrol and then drained both batteries...if you jumper the support battery, its possible the engine might start up to recharge the traction battery, depending on which battery is supporting that mechanism.

Agreed though, with normal use if the traction battery dies because it can no longer be charged, then you're jiggered and need a new one.

so you might want to wait a couple of minutes before you retry.

You mean run the engine for a few minutes before trying to start the other vehicle?


In any case, looks like the jumpers are going back in: I mainly end up using them to start other people anyway.

[Half-Borg]

As far as I know the Prius has no starter motor, the engine is started by the electric traction engine, which is powered by the traction battery at 200V. The inverter can only go one way from 200V to 12V to power the control units. So it is not possible to jump start your petrol engine, no matter how much current you can provide at 12V.
But the traction battery should have a safety shutdown to prevent depth discharge, so if the engineers at toyota are any good there should always be enough charge left to start the engine one more time, unless you drain your battery and leave your prius powered down for months so that it self.discharges

[happy]

That makes sense.

[annaraven]

We had to jump start our Prius twice. Once because my husband had forgotten and left it in Park instead of Off, and everything was still on (lights etc)! (He didn't realize there was a difference.) And drained the battery because we were at an all-day event. We got a jump, and got home. But then we had to get it jumped again, the next week - apparently draining the battery kinda killed it. So we had to get a new battery. That sucked. But we learned.

I always keep jumper cables in any vehicle, because you never know when you'll need to give someone else a jump. Yes, you can jump other cars from your prius. You just have to go figure out where the connections are - they're not the usual place, iirc.

[Allen]

I also own a Prius.

Here is the thing about running out gas (not your main question but you did pose it in your original post).  Just fill the thing up when it's 50% full.

Just always do it.  It can be very expensive repair wise if you truly run out OUT of gas.  So never, ever get in a situation where you could possibly even be close.  Go 250 miles like everyone else when they are out of gas, your tank will be half full.  Go fill it up.

You will never, ever, ever run into an out of gas situation.

As far as jumping, I don't know about jumping YOUR Prius, but be very, very careful if jumping another car with your Prius, it has a somewhat special procedure and if you screw it up  you can end up with an expensive repair.

[happy]

Thanks Allen. You know with my previous petrol car I never,  ever ran out of petrol.  The Prius goes so long on one tank, I found I stopped checking it routinely.  Then I found it has a little readout that tells you how many km  you can go on the remaining petrol.  I would usually never run my petrol car so low, but I found myself going, oh well, I can go 50 more km yet. Yikes! So I decided I would have to do as you say, always fill up at a certain level. (maybe half is overdoing it!).

As far as jumping another car, yes this is what I was wondering, (all those electrics)....so I will look up the correct way to do it with a Prius: I usually keep printed out instructions in a plastic sleeve with the jumpers, since I can never remember the correct order to avoid scary sparking.

[annaraven]

I have a set day every week (Monday for me) that I fill up the car. I learned that from a book on time management, that reminded me that if you make the maintenance stuff a habit, you can stop thinking about it. So, I set my garbage out on Monday night for the Tuesday morning garbage pick up. And I get the car refueled on Monday (no lines - I go to the Costco so the lines are long on weekends) and never have to worry about being out of gas. I also refuel anytime I notice the gas gauge below half. Not as an emergency, but next time I see a good price. I use Gas Buddy to find out the cheap gas near me.

In any case, don't let it go below a quarter tank. And if it's winter don't let it get below half. http://voices.yahoo.com/3-reasons-why-shouldnt-let-cars-gas-tank-11304700.html

[happy]

Thanks Annaraven, I didn't know about the fuel pump. We don't even get frost here, so there are no winter issues. I too used to fill my tank once a week because it was a gas guzzler, and moving away from this routine was problematic. Also at times I get a large discount on petrol from my grocery shop, up to 40c a litre ( petrol here is about $1.50 a litre), and so I had been running the tank down in order to get the biggest fill when I have a really good discount docket. False economy if I run out of petrol and bugger the engine.