How to help jump start other car ?

You should not have your battery connected to the dead car while they are trying to Start the engine.
That is Rule #1.
The Prius's little Lead Acid battery was never meant to crank an old fashioned ICE.

If you must be a good samaritan have your car up and running while connecting to the dead battery.
Don't power up that dead car.
Just let your car charge the dead battery while you have a cup of coffee or such.

Then disconnect and let them try to start the dead car.
If no joy,,, call in a professional, or someone with a bigazz battery and bigazz jumper cables.

 

That, and with the Prius I’d invest in those special jumper cables that make it impossible to attach the wrong way (blocks current if not connected right).

 

I have gotten beyond the jumping of other cars with mine. I carry a jump pack (not large, but big enough to start my Prius and to give a "boost" to a friend in need) and an AAA card. I do not carry cables. I don't mind using a call-out off my AAA card for someone that is in trouble that I know.

I will say, however, that public areas seem filled with scammers and I am more inclined to offer to call the police than to lend much assistance to someone I do not know.

BTW, a reasonable jump pack is about the cost of a good set of jumper cables anyway. I think I paid about $60 for my lithium ion unit.

 

My policy, when I had my Gen 1, was pretty much the opposite. I would have my battery connected to the other car while they tried to start, just not the rest of my car.

That was easy in Gen 1 (and Gen 2 also), because their battery cables plug in at the positive battery terminal. I would simply put my car in READY (so it was safely started before any risk of discharging the aux battery), then unplug the cables at the battery (you would never do this in a conventional car with an alternator, but the Prius DC/DC regulation has no problem with it), and jump the other car from my isolated battery, with no risk to the Prius electronics. When done, I would plug my battery cables back in and drive off, as the DC/DC recharged my battery.

The idea that the battery is too puny to jump another car seems fanciful. Most cars can be started with a pocket-sized jump pack. Sure, a large, balky, badly-out-of-tune truck in deep winter would probably be too much (either for the Prius battery or for a pocket pack). On the other hand, another car's starter can easily, if briefly, draw a higher current than the fuse rating on the DC/DC converter output, and that's a fuse that takes an inconvenient lot of disassembly to replace.

Alas, in Gen 3 the unpluggable battery cables went away, so the only way to isolate the battery from the electronics is to find a wrench and loosen the terminal posts, which I'm too lazy for, so I have joined the ranks of the pocket-jump-pack carriers (and yes, my pocket pack had no trouble starting a big ol' decrepit van one afternoon that I saw stranded in a parking lot).

-Chap

 

I carry a jump pack in the hatch under-floor tray, all the time: Clore JNC660, it's quite flat, fits nicely. About 20 lbs though. I have a memory saver cord with it too, can be used if you're swapping batteries on a car.

They're kinda expensive/heavy/bulky compared to the new ones though, I'm probably behind the curve.

 

Toyota says Do not do it.

From the 2011 US Manual:

 

Got it in one!
Welcome to PriusChat!
…and a very good reason to invest in a JumpStart PowerPack (there are dozens on the market) - I have two, and one is always in the car, ready to be used at a moment's notice, either to jump my Prius, or come to the rescue of a damsel in distress, or whatever!
Good luck!

 

I have the yellow one like yours also. Bulky but reliable and has 1,700 cranking amps. Best part is battery inside is user-replaceable, still works after 2 years.

 

This is the pack I have. Successful jumps of neighbor's Rav4 twice.

 

I think I paid $35 and it’s only 6 X 4 “, I would never jumpstart a ICE vehicle. When I had my 2012, I denied a couple of tipsy kids, they were totally clueless and thought I was not nice.

 

Why on earth not? The one I carry in my car is not much bigger than the one you describe (see threads passim for details - hint: use search), I've used it to jump my 2009 Gen II several times, various neighbours' cars (Corolla, Jeep, Honda, VW, Hummer), and wouldn't hesitate to offer assistance if I was given the opportunity!

 

I think @Andyprius1 meant he refused to jumpstart them with his car, prior to getting jumppack?

 

I carry a jump pack now and would use it to jump start another car.

If I didn't have one I don't know if I would offer but if I did I would connect the cables and just use my Prius to charge their battery and if they wanted to try starting it while connected I would say no and go on my merry way.

Some people just don't talk Prius.

 

I don't think a few minutes hooked up would do anything? And a stranger, sitting in his/her car, "promised" not to turn the key? Don't go there.

 

Correct.

 

That’s the same one I have, a great deal.

 

Absolutely correct.

Because there are multiple complications involved:
1. I bought the unit for the necessity of NOT ever getting stranded in the boondocks, just like, flashlight, spare tire, triangle warning sign, 12 V jack, warm jacket gloves, hand warmer, 12 V compressor. etc
None of this preparation was to assist strangers because they do not prepare.
Now if a neighbor asked for assistance I would gladly assist knowing that my neighbor is solvent and reliable and would have reimbursed me for damages. A stranger would just give me a incredulous stare.
There are many idiots driving that are totally unprepared for anything.
Returning from Reno after a snow storm a woman asked if I would take off her chains FOR her, I told her no,
but I would talk her thru the procedure. She declined as she didn’t want to get dirty! I mentioned she should have brought coveralls with her. I drove off. I’m sure she never forgot that incident and learned from it,, OR
I’m still a Bastard. oh, I also carry coveralls.
I taught my daughter how to change a tire, it came in handy in Mexico a boyfriend at the time did not know how.

 

I take your point, however, I try to treat folk as I would have them treat me! (…at least to start with) …so, perhaps what I really need is an IdiotFilter!

 

And a road side retroflective vest, with knife-proof armour...