Jump start Jazz from Hybrid Toyota?

[richardfrost]

My son left his Jazz Mk1 lights on all night. Does anyone know if the electrics on my hybrid Toyota Rav4 are compatible enough for me to jump start him?

Otherwise maybe a tow and a bump start but that will be very complicated given his driving experience and where the car is.

Final option may be remove the battery and bring it to my home for a long charge. Is removing the battery easy? I don't have too many tools.

[Jocko]

Should be no reason why you cannot jump start 12v battery to 12v battery. Hybrid battery is totally separate from that system.

[culzean]

My son left his Jazz Mk1 lights on all night. Does anyone know if the electrics on my hybrid Toyota Rav4 are compatible enough for me to jump start him?

Otherwise maybe a tow and a bump start but that will be very complicated given his driving experience and where the car is.

Final option may be remove the battery and bring it to my home for a long charge. Is removing the battery easy? I don't have too many tools.

If your Toyota has a 12volt starter battery can't see a problem as long as you clip jump cable directly  to battery terminals - a starter battery is a starter battery is a starter battery......... starting Jazz does not really take too much current compared to some cars.

The other way is to park next to the Jazz and put jump leads on and run your engine to put enough juice into the jazz battery to start it ( about 15 minutes ? )...  but if Toyota battery has the coulomb counting method for battery and the electronics is happy with the ins and outs of your battery ( ie thinks its fully charged ) the alternator may reduce its output - maybe you will need to load up Toyota with heated screens etc.

[richardfrost]

Should be no reason why you cannot jump start 12v battery to 12v battery. Hybrid battery is totally separate from that system.

That's what I thought until I googled it. Might be OK to use it to give it some charge but might not be powerful enough to start it. Going to try pushing first I think, or towing. So long as I can get it going he can drive round to mine and put it on a charger for a few hours.

[richardfrost]

My son left his Jazz Mk1 lights on all night. Does anyone know if the electrics on my hybrid Toyota Rav4 are compatible enough for me to jump start him?

Otherwise maybe a tow and a bump start but that will be very complicated given his driving experience and where the car is.

Final option may be remove the battery and bring it to my home for a long charge. Is removing the battery easy? I don't have too many tools.

If your Toyota has a 12volt starter battery can't see a problem as long as you clip jump cable to battery terminals - a starter battery is a starter battery is a starter battery.........

The other way is to park next to the Jazz and put jump leads on and run your engine to put enough juice into the jazz battery to start it ( about 15 minutes ? )...

That might be an option. Would be blocking other cars in though so will see what's what when I get there. Thanks.

[Basil]

The battery is easy to remove and shouldn't take long to put enough charge into it to start the car, you may need a radio code to get the radio working again though.

[richardfrost]

The battery is easy to remove and shouldn't take long to put enough charge into it to start the car, you may need a radio code to get the radio working again though.

Thanks. Think we have the code. Just trying to give it some charge from mine at the moment.

[culzean]

Managed to find details of a Toyota Yaris hybrid 12 volt battery and it is a 20 A/h unit,  so about half the size of a Jazz battery.  Makes me wonder if it has anything to do with starting the car engine or if that is done by using the main electric motor.  Yaris owners say if the 12v battery is flat the car will not start - seems everything is interconnected.

[richardfrost]

Well car was parked awkwardly so needed to be pushed around and then it turns out my battery is in the boot. Anyway, it wouldn’t start it. Then a neighbour turned up with a Polo and a jump from that didn’t work. Headlights were on all night so battery was properly flat. Removed it and left it in his kitchen on a Halfords charger but I have no idea how long that will take. His partner is well cross with him. She’s a nurse and comes off shift at 8pm so there’s our deadline. If he can collect her in the Jazz he just might get back in her good books.

I have never known a car not to start off a jump though. Just turned over once an nothing.

[richardfrost]

One thought is that my jump leads might be crap. I did notice they got really hot whilst we were attempting the jump start.

His battery was put in by the RAC when his brother had the car so won’t be more than 4 years old but it really only gets a few local journeys so probably never gets to full charge anyway. It’s a Varta battery badged for the RAC.

[Ralph]

Hello not been on here for a while due to me now owning a Toyota Yaris hybrid, I can confirm that the 12v battery doesn’t start the engine it just power’s up the Cars computer and accessories and turns on the high power system so the traction battery can start the engine when needed. I doubt the 12v system is rated to start an engine so jump starting another car could possibly damage the Toyota

[richardfrost]

Finally had some time to read and research myself. The 12v battery (in my boot) is not used to start the car, just to start the electrics, as the previous poster above has said, so in this respect my RAV4 is like the Yaris. There are jump start locations under the bonnet to start the RAV4 but I have so far not found anything about starting anther car FROM the RAV4.

I am a little concerned that the Jazz didn't jump start from the Polo, but that may be down to the quality of my cables. I think they might have been a petrol station bargain, a bit like my old steel tow cable, which broke the first time I used it rescuing an out of fuel VW bus from a dangerous bend before the RAC got to her.

I am hoping the battery will recover using the Halfords charger, but I suspect this might be a 12 hour job so I'm not holding my breath. Failing that the local Halfords have a Yuasa battery in stock I can get tomorrow for £89. Seems expensive but needs must.

EDIT: After more reading, I am finding that it is not a good idea to attempt to jump start FROM a hybrid and I am not surprised it wasn't successful. I am relieved that the RAV4 seems to have survived.

[Jocko]

A 20Ah 12v battery should be more than adequate to jump-start a car but if they are saying don't do it, don't do it.

[richardfrost]

A 20Ah 12v battery should be more than adequate to jump-start a car but if they are saying don't do it, don't do it.

Well 20Ah is for the Yaris. My RAV4 has a 2.5l petrol engine so battery might be bigger. I think the issue is the battery is only there to run the 12v systems, not to start the car, and is therefore not set up to provide such a high current. There's a +ve jump start terminal in the engine compartment which you are supposed to use to jump start the RAV4 with. So I am guessing trying to do it from the battery terminals in the boot will probably attempt to pull a huge current through the DC voltage converters from the high voltage system and that’s where the damage could occur. I was probably saved from damage because of the crappy nature of my jump leads.

[richardfrost]

After a good 11 hour charge yesterday, we refitted the battery this morning and all is good. I educated my lad on the need to do the occasional long run, especially during lockdown. Basically, he uses it to go to Tesco or visit us and she uses it to get to the hospital and back. Maximum journey time is maybe 15 minutes, so the battery was probably suffering anyway.