Question brought on by the battery in my other car dieing last night.

Is it ok to use the TCH to jump start another vehicle? Any special precautions?

I looked in the owners manual and saw it was ok to jump the TCH to get it started and I didn't see any warnings about the other way around.

 

I don't believe so.
This was from the FAQ in my signature

 

Thanks Haroldo, I thought I remembered reading something but couldn't remember for sure or where.

 

That wasn't my answer...I just found it in the forum and added it to the FAQ.
Me...I aint going anywhere near anything electrical on this sucker.
I'm afraid I'll break the Flux Capacitor!

 

Beore reading this I infact did jump my truck with my '09 TCH. All was well before my wife tried to drive it and it produced a "check engine light" with associated "check hybrid system" light. I attempted to contact the inept dealership, and since they are the only one in town they let me know that they would call me back. So I hit the internet and stumbled on to the thread about changing the 12V battery. Success. After three start up cycles the fault was cleared and no more light. Needless to say I will not be jumping anything with the TCH again. I beleive I was lucky with the easy fix.

 

You could disconnect the positive from the 12 volt TCH battery. Then use the jumper cables from the weak car battery to the TCH cables. That would be + to +. Do not have the TCH battery post attached on the positive + side. Crank the TCH with the weak battery and allow it to charge at or near idle for 10 minutes. Be sure to remove the jumpers and then see if the other car will start.

The TCH when running, should put a pretty strong charge into the weak battery. The weak battery should easily power up the ecu in the TCH so the traction battery can start the engine.

A jump like this should work and protect the deep cycle battery.

 

Easier (and safer) to call AAA...IMHO

 

The 12 volt in the TCH doesn't run the starter; the traction battery does. You can't jump the TCH conventionally. If you use the TCH to jump another, it would not be advisable.

The heat generated by the process could damage the AGM battery. It's designed to handle the electronics systems, not take the high current cycles involved in running the starter. The only Theoretical way to jump another vehicle would be to use the TCH battery as a charger for a low battery on the jumped vehicle. Only hook up the cables to bring the battery back up to where it could do the job itself, then unhook the cables and let the jumped battery try to start the car.

This would only be a 'last resort' type of maneuver. Despite the outward appearance, this is not a starting battery, it's a power supply battery for the electronics.

You might be able to bring up a starting battery on another car by jumping from a running TCH in a situation where someone had left the lights on, but only use the TCH as a battery charger, not as a starter battery. But only in the most desperate of circumstances.

Again, this is only theoretical for applications of direst need.

 

After reading your post, I remember our local Toyota tech called it the instrument battery.