Can you jump start hybrid battery?

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01-21-24, 02:30 AM

#16

ggebhardt

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After reading how many have had battery problems with their 350h, I do not think I would offer to help jump start anyone. I own a large portable jump starter but it is heavy and required charging every once in a while.

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01-21-24, 05:01 AM

#17

BillUK

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Quote:

Originally Posted by jahnjva

BillUK you said "A separate point worth mentioning, is that whilst you can jump start a hybrid car from another car/battery pack, you can't jump start another car from a hybrid. The 12v battery/system in a hybrid isn't designed to push out the required power to start an engine, and could cause damage if you try." So you should not try to jump start another car from the front fuse box positive terminal. What about jumping directly from the 12 volt battery in the back of the car? My guess would be that that shouldn't be done either?

I wouldn't do it. The 12v battery is only designed to power up the hybrid and run a few accessoroes, it doesn't have the crakinng amps to start an engine. My personal recommendation to anyone (hybrid owner or not) is to buy one of those small jump starter packs and keep it in the car. That way you can not only start your own car if your battery goes flat, but also give someone else a jump start with it if they need help. I got a reasonably inexpensive one from Amazon a few years ago, and it's started everything up to a Jaguar V8.

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01-21-24, 06:20 AM

#18

WellsB

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Quote:

Originally Posted by jahnjva

What about jumping directly from the 12 volt battery in the back of the car? My guess would be that that shouldn't be done either?

If I were to feel a strong need to jump another vehicle from an RX hybrid, I would do it directly from the battery with the RX completely shut down. That is actually the safest way to jump start from any vehicle. I've found that to be sufficient most of the time in starting another vehicle and, if that doesn't work, then starting the donor vehicle usually won't work either.

Basically, you are using your vehicle's battery in the same way that you'd use a portable jump starter. There is a concern that it could leave your own battery dead if the jumped vehicle doesn't start right away though.

Last edited by WellsB; 01-21-24 at 07:36 AM.

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03-13-24, 07:15 AM

#19

wrinkle

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Quote:

Originally Posted by WellsB

Your traction battery is under the back seat and impossible to connect to without taking things apart. It's also high high voltage. Your 12v battery is in back under the cargo floor. Usually you would jump it from the front under the hood though. There is a positive connection in the fuse box and a negative connection on the engine.
Here is a video on how to jump a Lexus hybrid.
https://youtu.be/CShZN2P8di0?si=d_cXg3c1OOWVLZCN

So I wanted to confirm, given that I seem to foresee having to do this very soon: What is the correct order for connecting the leads in terms of positive/red and the negative/black ? This video shows connecting the black/negative first, followed by the red/positive to the battery last, which seems to make sense. However, in many other videos they seem to do the opposite order. Or does it not matter ?