Hi, I drive a 2015 Prius C and I’ve heard that using my Prius to jump start other cars is a bad idea. I’ve been in a couple of situations where I was the only car available, and it felt awkward to say no. There’s so much conflicting information online about whether you can or can’t jump start with a Prius. I’m thinking of getting a $40 mobile jump starter to keep in my car for future situations, but I want to know if that’s really necessary and if using a Prius to jump start another car is hard on the hybrid.
Never jump start a car from a Prius. I refuse to jump from my SUV now too. I’ve killed two alternators in the SUV after helping others, even though I’ve done it about 15 times. The $99 CAT battery jumper from Costco is great and has never failed me, even if it took a few tries to jump.
@Kaius
So you’re saying jumping others stresses modern alternators? Most newer cars don’t regulate voltage in the alternator, but rather have an ECU.
Hadley said:
@Kaius
So you’re saying jumping others stresses modern alternators? Most newer cars don’t regulate voltage in the alternator, but rather have an ECU.
I’m not saying much other than I killed two alternators in my SUVs shortly after jumping other cars. Since I stopped providing jumps, I haven’t damaged another alternator. Take from that what you will.
The high voltage system in the hybrid battery is completely separate from the 12V battery system in the Prius. You can use the 12V battery in your Prius to jump start another vehicle without any issues. The inverter separates the systems and acts like the alternator.
@Lloyd
This is correct. I’ve worked on a lot of hybrids and EVs and it’s fine to jump from them since the 12V system is separate. However, I wouldn’t recommend jumping larger engines from a small car. A separate jump box with high cranking amps is better for that.
@Lloyd
While the battery is under the rear seat, there’s usually a spot to clip a positive lead around the fuse area under the hood. I usually ground off a bolt like on the strut tower assembly.
Quinn said:
@Lloyd
While the battery is under the rear seat, there’s usually a spot to clip a positive lead around the fuse area under the hood. I usually ground off a bolt like on the strut tower assembly.
True. I’ve noticed there’s always a loss in amperage when using those lead points, but it’s worth a try.
@Lloyd
Yeah, typically I use those points when I’m giving someone a jump.
Quinn said:
@Lloyd
While the battery is under the rear seat, there’s usually a spot to clip a positive lead around the fuse area under the hood. I usually ground off a bolt like on the strut tower assembly.
That’s not for jumping your car.
@Amari
Well, it’s how you jump the car, so there you go.
A lot of people say the 12V system is separate from the hybrid battery and it’s safe to jump another car. This is partly true. If you’re jumping another car with the Prius on, the DC/DC converter inside the inverter powers all the 12V systems and won’t handle the surge from cranking another car. You might blow a fuse if you’re lucky enough not to damage the inverter. If the car is off and you jump another from the 12V battery, you should be fine. Note that the jumper terminal in the Prius fuse box is for receiving a jump, not providing one. You could overload the wiring or blow a fuse trying to jump another car. The safest way is to turn off the Prius and jump from the 12V battery directly, but don’t do it often or with larger cars since the 12V battery can’t provide much power.
The hybrid has multiple computers, so I wouldn’t jump any car. The surge can blow an ECU or fuse, and replacing an ECU is expensive. Use jumping as a last resort. A portable jump starter is a good idea. I keep one in every vehicle and have jumped my GS450h without issues. If someone needs a jump, I use my jump starter on their car.
@Flippa
So it’s not okay, but it is okay?
CharlotteMia said:
@Flippa
So it’s not okay, but it is okay?
For me, it’s a hard no. I won’t jump a vehicle with my car. It’s about peace of mind versus spending thousands on a new ECU.
Don’t jump cars from your Prius because the 12V is undersized. It only powers systems, not a starter like standard vehicles. I bought a jump pack for this reason. Modern jump packs are easy to use and minimize user error. I charge mine a few times a year, and it has started every vehicle I’ve needed to.
@Sadie
That’s the plan now. I’m looking for a decent, affordable one. Both situations I found myself in were tough. One was a friend with a terrible battery relying on jump starts to start her car. Luckily, her car started on its own. The other was an older lady at the dog park whose friend needed a jump after leaving the lights on. I called AAA for them and then waited in my car so they wouldn’t be left alone. I saw others leaving the park and asked if they had cables, and luckily they did.
@Tilden
Yeah, I’m guessing it’s younger people downvoting jump pack suggestions. But honestly, even without a Prius, it’s better than having jumper cables. I got mine on sale for about $50 on Amazon. Everyone should have one. My family now has them in their cars, and you can use it to jump the Prius too.
Go ahead and do it if you want to damage the electronics. Jump starting a regular gas car can draw up to 300 amps. A hybrid isn’t designed for this because it doesn’t have a starter. The 12V battery is for powering computers and small accessories.
@StellarToyota
No, don’t use your Prius to jump another car. It could blow the other car’s battery and ruin its computer system and fuses. This happened to me when my son’s friend’s Prius died at my house. We jumped her car, then ours was messed up. I had to buy a new battery, and our fuses blew later. It’s not good for the other car.