What Happens When a LS600hL Battery Fails?
 

Do you have to have it replaced? Or can you simply continue to drive the car as a regular V8?

Replaced... In theory, you should be able to run the V8 - once it's on. However, putting aside all computer-related issues, warnings, and possible lockouts, the main problem I see is that you couldn't get the 5.0 started. The hybrid batteries spin Motor-Gen 1 that cranks the engine. 12V battery only trips relays that allow this to happen (and also powers accessories when system isn't on).

caha is right, the hybrid drive train is used to start the gasoline engine. My guess is that the battery would not just fail all at once despite the car warning light but run on a degraded state. As long as it supply enough voltage to start the car you would probably be able to stretch some miles by being very careful not to store the car with a low hybrid battery. But then again, you might end up using the electric motor and converter much more often and in the end it might wear other components prematurely. I also have the feeling that converting the car to gasoline only by adding a second regular 12v start battery in the trunk to start the car would not be that easy. The car probably use a complex system to regenerate the battery and convert current to the right usable voltage. Changing a few part out of warranty of that hybrid system quickly surpass the price you'll pay for a used 460 if you don't want to put up anymore with the hybrid stuff.

Ah, thanks guys. I was wondering what would be the big deal if the hybrid battery failed. Now I know it is a big deal.

If only Lexus would let it be pushed in second gear while I let go of the clutch easily, I could get 'er started... LOL

I heard that the gas engine should take over to at least allow you to get to where you need to go. But either way, if I get stuck, Lexus or USAA roadside is coming to scoop my ride on the flatbed