Jumping other cars?

I agree with Evan it is best never to jump another car with your Prius battery, it may be to small to do the job anyway. But if you do make sure the Prius is turned off, if it is not and you hook it up wrong you could damage some very expensive components. If you remove one or both of the battery cables from the Prius it should be safe but you might run the battery down.

 

The manual cautions you're not supposed to. The manual also points out the approved emergency jump start connection under the hood in the main fuse box. Good luck getting regular booster cables to clamp onto THAT!

I suppose in a real emergency, just leave the cables connected to the dead car for 10-15 minutes, but do NOT attempt to crank the dead car. Disconnect the cables, try to start the dead car. If no joy, repeat charging 15 minutes.

When I first took delivery of my Prius, Canadian Tire had a sale on their emergency car boosters. I got a 700 amp model for $60. I leave it in my car all the time, taking it out once a month to charge it.

I've used it four times now, boosting small cars up to half ton pickup trucks, with no problem. It does the job and if worse comes to worse, you've cooked a $60 gadget instead of something expensive like in the inverter/converter.

Even with a conventional car I'd use an emergency booster instead of the car to jump start. With the huge surge involved, I wouldn't want to risk an alternator, regulator, or other parts in a conventional car either.

 

Along the lines of the other replies, it's not ideal to use your hybrid to jump other cars. Asside from the aparent extra-sensetivity of the Prius and potential damage from reversing your cables here's a little more technical info on why it doesn't work well, even when done correctly...

The Prius, and other hybrids, don't have a "standard" alternator attached to the engine and semi-dependent on ICE RPMs. With a traditional jump start you connect the vehicles and then slightly rev up the good cars engine to get more power out of the alternator which helps to charge the dead cars battery more rapidly. Since in the hybrid we can't do this we simply have to leave the hybrid running and charging the dead car at whatever rate if feels is appropriate. So you may need to sit there trickle charging the dead car for 15 to 30 minutes before it's capable of starting on it's own. Sure it can be done, and if you're the only passer by on a descelet road with noone else arround for days then a half hour of jump starting may not be so bad. But if there is anyone elses arround with a regular car the stranded party will get better/faster results from a jump start from that other vehicle.

I did use my Insight to jump start a friends car and it took 30 minutes before there was enough charge on his car to turn over his engine and get it started, perhaps also partially due to my crummy cheap cables. I didn't disconnect the cables when cranking over the dead car, but that may not be a bad idea, probably not nessecary, but might aswell play it safe. Ideally you would have with you a portable jump-pack for your own car which would be better to lend to the dead car to get it started.

 

Evan, et al: What about accepting a jump start from another car?
Bob

 

<div class='quotetop'>QUOTE(Bob Allen @ Dec 12 2006, 06:54 PM) [snapback]361216[/snapback]</div>

That should be fine, you only need just enough juice to boot the car, run the brake boost pump and coolant transfer pump, and close the HV relay. Though it would probably be a good idea to pull the 12 vdc battery from the Prius and put it on a real charger until fully charged.

I think the hardest part of accepting a boost is the tiny jump start terminal located in the main fuse/relay box. Wouldn't hurt to rig up a one foot or two foot long 6-8 ga wire with an alligator clip one one end and a battery terminal lug or post on the other end. It doesn't have to handle a huge amount of current.

Otherwise you're folding down the rear seats, using the emergency release on the hatch, and taking the trim pieces off the passenger corner side to expose the tiny 12 vdc battery.

 

<div class='quotetop'>QUOTE(Locust43 @ Dec 10 2006, 10:43 AM) [snapback]360067[/snapback]</div>

Your Mother!! Bummer dude. My usual reply is "how does your electrical system handle 500 V?" OK I am exaggerating and being mean spirited. I do offer to call for help and some big stores and such have a jumping service. Our hospital and clinic has security people that do it. You would be amazed at the number of services like this that are around if you ask.

 

<div class='quotetop'>QUOTE(Locust43 @ Dec 10 2006, 12:43 PM) [snapback]360067[/snapback]</div>

locust43,

I agree with jayman, get yourself a good jump pack. I got one with air compressor and all on sale for $20 US last Christmas. Usually, $40. This is great for PRIUS owners who love to keep the tires within spec with the air compressor.

I have used mine many times to help others jump start their cars. It is nice to be able to help others. One time I was running late for work and I saw someone needing a jump in the parking lot of where I worked. Since I did not have time to help them coneect it and start the car, I just gave them the battery pack and told them to return it to me when they were done.

Battery packs come in great when on camping trips and you need power to run the radio or a big spot light to find your friend who are lost in the woods.

Good luck!

 

<div class='quotetop'>QUOTE(jayman @ Dec 12 2006, 04:02 PM) [snapback]361221[/snapback]</div>

I think most people are under the impression you need to connect to the small threaded bolt (positive terminal) that's under the protective cover in the main fuse box. That's not the case.

If you look in that same area, you'll notice that there's a metal "flap" above the bolt that's also connected to the "positive" bolt. You can use the metal flap as the positive connection, and it's far easier to make a connection on.

Dave

 

<div class='quotetop'>QUOTE(DaveG @ Dec 13 2006, 11:53 AM) [snapback]361552[/snapback]</div>

Dave

The little silver "bridge" behind the bolt does help a lot, but if you have a heavy duty pair of cables with those angry-looking clamps, it's a tight squeeze. A foot long or so jumper wire would really help the average Prius driver.

My 2000 GMC Sierra had a jump start point around a foot away from the battery, near the power steering pump. That bolt was easy to clamp any booster cable to, or a battery charger for that matter.

jay

 

Just jump started a 2001 Honda Odyssey with the Prius. Its battery had drained since the car was left on in accessory mode. After connecting the cables in a normal manner, I started my Prius, waited a minute, and then started the van with no problems.

Where does it say in the manual not to do this? I understand the points about the smaller than normal battery and how the charging system differs from other cars. But where is the legal 'do not do this' disclaimer?

If I was wrong to do this, then shame on Toyota for not allowing we Prius owners to be good samaritans!

 

Also a slight twist on the questions: What about a Prius jump starting another Prius? Is that OK? (I mean technically, not morally, since it's gotta be some kind of incest...)

Anyway, yes, get a jump pack and you'll always be able to jump start your own car or someone else's.

 

I would never try to jump start another vehicle with my Prius, except another Prius. As I have a high quality battery charger I would also never try to charge the battery in another vehicle with the Prius. Be aware, the Prius battery is protected by a 150 Amp fuse, and some cars in cold weather can draw more than that, if you can get a good connection with very good cables.

In an emergency, I would accept EMF from another vehicle, with their engine off. To that end I made myself a "Prius booster cable". I have a high quality booster cable which weights 30 lbs. Too much for a Prius. So I made this cable using finely stranded #10 cable (intended for electric outboard trolling motors) and solid copper Mueller clips. The small clips are for the Prius end (+ve or red on to the terminal in the fuse box under hood - -ve or black to the bolt on the firewall just above the fuse box), the large clips are for the "doner car" end.

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I did measurements of what the Prius needs in terms of current, and found the brake boost hydraulic pump draws about 35 Amp in a pulse of 1/2 to 1 sec. (when you press the brake pedal to get ready to go to "Ready"), and the car draws about the same when you press "ON", again for 1/2 to 1 sec. Then the system begins to charge the 12 V battery from the traction battery - I saw about 10 A initially. The 12V battery was not dead in this case.

When boosting cars it's not the cable that's the limiting factor in how much current you can transmit, it's the connection of the clips on the battery posts (as long as the cable is reasonably sized and not too long). If any post is corroded, fix that first. When you connect the first three clips wiggle them to ensure they are well connected (abrade any oxide off the connection). That's the positive to positive and negative on the Prius. The final connection is the other end of the negative (black) to the chassis of the doner car. It will spark, so be ready. Wiggle it as well, once connected, to reduce contact resistance. You could just connect the cables and leave them that way for a few minutes, then disconnect the negative on the chassis of the doner vehicle and try to go to ready. If it works you will reduce the chance of a "spike" damaging either vehicle. If not reconnect and try to go to "ready". Disconnect the black negative on the chassis of the doner vehicle first, then the negative on the Prius, and finally the two positive red clips in any order you like.

 

Hi all,
This is my 1st Post here. I have had my Prius only 2 days now. But I recently was on a camping trip where our camp mates had 2 hybrids, and one got a dead battery. They had a Ford Escape that wouldn't start. and tried (unsuccessfully) to jump start it with their Prius via the jumping terminals in front. I ended up jumping the Escape with our conventional car's battery.

We all assumed that the terminals were voltage limited in a way that they could only be used to jump the Prius, not use the prius to jump other cars. Is that a possible scenario? If I hadn't been around, their next plan of action would have been to use the battery, in the rear, directly. As this world gets filled with more and more Hybrids (we can hope), the idea of hybrid to hybrid jumping is going to become more important.

BTW, The Escape had it's battery under the hood like a conventional car. But I was amazed at how small it's battery was. I suspect that the Prius is even smaller though.

 

Hi Aces, welcome to PriusChat and congratulations on your new Prius! I don't think any terminals are voltage limited. The main limitations come from the small size, both physically and electrically, of the Prius 12V battery. I suppose there is also some limitation imposed by the wire that brings the + side of the battery in the back to the terminal in the fuse box under the hood.

I believe your friends could have hooked their Prius and FEH batteries in parallel and started the Prius to Ready. That would have charged the FEH battery after a while it it could have then started by itself, with the vehicles disconnected. Neither the Prius nor FEH need instant cranking power, just 35A for a few seconds (according to David Beale) to work the pumps and boot the computers.

Enjoy your new car and welcome again.

 

There is a new system out where you can charge a car's dead battery from using the cigarette lighter sockets. You don't even have to open the hood or use jumper cables. You connect both cars wait 5-10 minutes until the thing says the carge is complete. Then you start the car. Has anyone heard or used one of these ? If so, would it work and be safe for a Prius ? Could it be used to start a Prius ?

 

Unless you rewire the "cigarette lighter" socket, it's dead/disconnected from the 12V battery unless the car is on, so this gizmo wouldn't work in a Prius.

 

That's what I need to know. Thanks Bill !!!

 

If you're worried about a dead Prius battery, buy the portable boosting device. If you can find one at $20 it's the cheapest alternative. Even at $40 it's close to the cost of the cable I made. Those solid copper clips are not cheap!

With one of the boosting devices you can safely give others a boost. You can safely boost your car. No danger of exploding batteries (in the doner car). No danger of spikes taking out your electronics (just keep the polarity correct). You can easily find them with air pumps as well, and flashlights, both built in. Only downside is you have to remember to plug them in once in a while.