ReggieRx

Another thread reminded me of a question I’ve been wondering in case of a dead battery…

Can the RX 350h hybrid battery be jump-started just like a normal car battery? Or should hybrid batteries not be jump-started?

We had a Toyota Highlander hybrid that got a dead battery. AAA refused to jump it saying hybrid batteries shouldn’t be jumped. We had to get it towed to Toyota service instead who replaced the battery.

If hybrids can be jumped as normal, I wanted to buy a battery booster so I can jump the RX 350h myself if needed.

Edison_Chen

If you’re talking about the 12v battery, yes you can jump the car. Under section 7 - Steps to take in an emergent in the owners manual has steps on how to jump start the car.

i purchased a battery booster/jumper in case my 350h battery died again.

ReggieRx

now I feel dumb, but is there another battery in the RX350h besides the 12v? I’m not sure what I have.

BillUK

Yes, there are 2 batteries. A regular 12v battery and the hybrid battery. In very simple terms, the 12v battery runs the accessories and powers up the hybrid system, and the hybrid/traction battery drives the electric motors and charges the 12v battery.

If the car won't start, then it's usually the 12v battery that's flat and therefore unable to power up the hybrid system. In such a case the 12v batttery can be jump started in the usual way.

ReggieRx

Thanks for this explanation! Now I’m going to find the batteries so I don’t try to jump the hybrid battery accidentally at some point. Clearly I’m not a car aficionado!

LeX2K

Interesting that this has come up I talk about the issue here

Not sure this is true for current Toyota/Lexus hybrids anyone here know?

You can't accidentally jump the high voltage hybrid battery.

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.

BillUK

I'm not sure about curent models either, although if forced to guess I'd say it's the same.

The trouble I see is that whilst it's possible to force the gas engine to run, via maintenance mode, it's needs power from the traction battery to fire up the starter.

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.

wrinkle

This is good information and learning above - of not inadvertently trying to help another person by jump-starting their car with my hybrid.

On a related note, I notice that two items/comments in this thread - one by myself and another by WellsB, that were added after WellsB's video addition, where I asked about which kind of battery maintainer/charger to keep in a hybrid/PHEV, and WellsB advised - have now been deleted, presumably by the moderators (?)

Can the moderators please explain why they deleted those two exchanges in this thread ?

WellsB

They got moved here.
https://www.clublexus.com/forums/hyb...ispreloading=1

I've seen that happen a lot here, as well as posts disappearing. I don't know if it's done manually by admins or automatically.
Very annoying though....

ggebhardt

‘I see a LOT of posts disappearing! I have been visiting these forums for near 20 years now and it is not moderated like it used to be. Even a slightly off topic comment will get the vanishing treatment. Still a great forum.

This post will soon disappear!

WellsB

It ends up making things confusing when half of a conversation is in one thread and the other half is in another.

wrinkle

Indeed, when there are multiple threads started by two different people on the same or similar topic, moving subsequent posts from one thread to another seems arbitrary/ pointless at best and confusing/misleading at worst. This is what happened here.

If the goal is better organization, then the threads can be merged, not posts suddenly moved.

ggebhardt

It goes beyond that . . . .

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?