Toyota Prius Forum banner
1 - 20 of 25 Posts

·
Registered
Joined
·
3 Posts
Discussion Starter · #1 ·
The manual explains how to jump start the Prius if the auxiliary battery is depleted. It does not say that you can jump start another vehicle with a drained battery. Does it work both ways? My Sienna needs a jump...
 

·
Registered
Joined
·
7,161 Posts
Due to all the electronics in the car, and the alternator equivalent of a conventional car, is a DC/DC converter incorporated into the expensive inverter, I wouldn't chance inducing an overload to the converter, or sending a possible voltage spike to the electronics.

I might try a quick charge to someone else's battery, but I would not have them start their car while mine is connected to theirs.
Better to get one of them battery booster packs for them and yourself.
 

·
Registered
Joined
·
114 Posts
hyperion said:
My guess would be that if you reverse the process and as long as your ICE was running you could do so with no problem. I have seen it done from a motorcycle to car.
Sounds like a really bad idea.

The inverter can provide 100 amps max. The donor car could easily draw 250 amps or more when starting. If the donor car draws more than what the inverter and Prius 12v battery can provide, you'll blow the fuse between the inverter and the 12v battery in the Prius. Luckily for you they fused the link so foolishness such as this won't result in permanent damage.

If you're forced into this situation, use the Prius to charge the donor vehicle's battery, and disconnect it before trying to start the other vehicle, as DanMan32 suggested.
 

·
Registered
Joined
·
928 Posts
The strategy I've heard is to get a really cheap set of jumper cables with really thin wire. That will limit the current to the car with the dead battery. Get the Prius into ready, then hook up the batteries and wait a while (around 10 minutes). This lets the other car's battery recharge (if it's able to). Then try to start the other car, but only for a short time.
 

·
Registered
Joined
·
1,043 Posts
kelcuk said:
The manual explains how to jump start the Prius if the auxiliary battery is depleted. It does not say that you can jump start another vehicle with a drained battery. Does it work both ways? My Sienna needs a jump...
If you are not a member already, join a AAA-like motor club, or add road side assistance to your insurance for these type needs.

Dont screw around with your new Prius...or any modern car loaded with sensitive computer modules & circuitry...except as detailed in the manual by the manufacturer.
 
  • Like
Reactions: tron8493

·
Registered
Joined
·
1,000 Posts
Not sure about this from a safety perspective, but maybe try just unplugging your Prius 12v accessory battery, and hook jumper cables directly to it, then try to start the other car. Yeah, it's a small battery with very little juice, but it should have enough for at least a single start of a normal car. Then hook it back up to your Prius, and let your Prius charge it back up.

(The safety factor is that I was thinking of trying it with the Prius on, so you don't lose any accessory-battery-related settings, because the HV battery pack/DC-DC convertor will be powering the accessory items.)
 

·
Registered
Joined
·
1,043 Posts
An auto club membership or add-on road assistance to insurance costs in the range of $40+. a year. And that can include all kind of additional services like flat tire changes, towing, free maps, etc, as well as jumps.

I dont think anyone should risk major damage to sensitive circuitry/computer modules for something not desribed in the manual. You will likely lose warranty coverage.

I got Toyota roadside assistance as part of purchasing pre-paid service for Prius...and I also kept my AAA membership for its many other services.
 
  • Like
Reactions: tron8493

·
Registered
Joined
·
669 Posts
I actually got roadside assistance with the Prius as part of the deal -- is that another CA thing? I also still have AAA. Unfortunately that doesn't help my colleague in the parking lot at work who wants a jump start and doesn't have those... so enquiring minds would like to know!
 

·
Registered
Joined
·
7,161 Posts
priusenvy said:
hyperion said:
My guess would be that if you reverse the process and as long as your ICE was running you could do so with no problem. I have seen it done from a motorcycle to car.
Sounds like a really bad idea.

The inverter can provide 100 amps max. The donor car could easily draw 250 amps or more when starting. If the donor car draws more than what the inverter and Prius 12v battery can provide, you'll blow the fuse between the inverter and the 12v battery in the Prius. Luckily for you they fused the link so foolishness such as this won't result in permanent damage.

If you're forced into this situation, use the Prius to charge the donor vehicle's battery, and disconnect it before trying to start the other vehicle, as DanMan32 suggested.
That's my logic too. However, when my dad and I were talking about Prius' features, including the solid state DC/DC converter in place of a conventional alternator. Although the coverter fuse is 100A, I believe the converter is rated at 80A. My dad mentions that output is typical of most alternators.
So, if a conventional car could not deliver more than 80A, other than what the booster car's battery itself would deliver, there shouldn't really be a problem with the Prius.

Another thought: If you let them boost off of your battery while the Prius is NOT in ready, then you shouldn't damage the converter, though you may kill YOUR battery.
But I still wouldn't let someone start their car off of mine.
 

·
Registered
Joined
·
163 Posts
Back when I was driving $100 junkers, I decided not to jump other cars. It seems the cars that need the jump have problems that do things like blow your alternator. I still feel the need to help others, so I had to find a solution.

I got a booster pack thing that plugs into my cig lighter. I also (idea stolen from here, IIRC) got a solar powered trickle charger (~$20 RadShack) for the brick to keep it full in the trunk.

1) Charge brick first, trickle charger won't do that well.
2) Works like a champ. I've used it a dozen times.
3) Velcro the heck out of it to attach it to the body or you'll hear a CLUNK shortly.
 

·
Registered
Joined
·
1,043 Posts
Astrowoman said:
I actually got roadside assistance with the Prius as part of the deal -- is that another CA thing? I also still have AAA. Unfortunately that doesn't help my colleague in the parking lot at work who wants a jump start and doesn't have those... so enquiring minds would like to know!
If you are AAA member, & a passenger in a non-AAA members vehicle, that needs a AAA service such as lock-out, jump, etc. AAA will respond on your membership. At least they did for me as a passenger in a non-members vehicle.
 

·
Registered
Joined
·
610 Posts
:roll: There is absolutely NO WAY I would consider jump-starting a conventional vehicle from my Prius for many of the reasons previously mentioned in this thread. I suppose jumping another PRIUS would be OK.

My 2¢ worth...
 

·
Registered
Joined
·
669 Posts
OK, maybe I'm being ignorant here, but what is different about the 12V system in the Prius that makes it more risky than a conventional car to give a jump start. The manual suggests that it is quite all right to recieve a jump start... is the primary issue the battery size, or are we just worrying more about surges because we have more (and much more obvious) computers in these cars?

Are those portable battery pack dealies you charge off the cigarette lighter really safer than the jump start itself?

I don't think Prius owners will be popular if we adopt the attitude of "sorry, can't jump start you, I have an environmentally friendly car...".

OTOH, I suppose I could make use of that space where the jumper cables are currently stowed....
 

·
Registered
Joined
·
7,161 Posts
Astrowoman said:
OK, maybe I'm being ignorant here, but what is different about the 12V system in the Prius that makes it more risky than a conventional car to give a jump start. The manual suggests that it is quite all right to recieve a jump start... is the primary issue the battery size, or are we just worrying more about surges because we have more (and much more obvious) computers in these cars?
Yes, both battery size and electronics. What used to be an alternator is now a solid state, electronic, switching power supply. You don't want to overload it. Granted, an alternator has diodes that could be blown, but an alternator costs a whole lot less than our inverter.

Astrowoman said:
Are those portable battery pack dealies you charge off the cigarette lighter really safer than the jump start itself?
Yes. While being used as a jump, the worse that could happen is you blow its one, easily replacable fuse. You don't plug it into the power outlet while you are jumping.
 

·
Premium Member
Joined
·
888 Posts
Astrowoman said:
I find it interesting that the manual (I checked) goes into great detail about how to receive a jump, but says zero, nada, zip on the topic of giving one.
I'm fairly convinced that is Toyota's way of saying, "The Prius is not designed to provide jumping service to every sorry soul out there with unreliable transportation. If we aren't instructing you how to hook up your vehicle as the donor vehicle, then you shouldn't do it."

This sounds terrible, but if you are driving a junker, you should probably pony up for AAA. Yeah, if you are driving a junker you also probably can't afford AAA, but I think you are between a rock and a hard place on that one.

I will be seriously considering getting one of those jumping bricks to carry around.
 

·
Registered
Joined
·
4,873 Posts
Hey, the manual doesn't mention a word about installing and using an EV switch either. But everyone is right. The Prius is not at all similar to the car you have been driving for the past thirty years. So have the dead battery jumped by a friend with another vehicle. You'll have to wait all day for triple "A" ( at least it will seem that long)
And about "junkers, " I have seen many posts about finding dead batteries in new Prius's. Thats why the manual gives you instructions on "receiving" a jump!
 
1 - 20 of 25 Posts
Top