Swiss Car Guy Replace 12 Volt Battery. Fixes Minor Errors.
 

Yes, I was following that. His 12-volt battery was 10 years old, so there’s a good chance that was the problem. It’s pretty rare for the LS 600h’s hybrid battery to fail, but if the 12 volt battery fails, it can cause all sorts of issues. If the battery is bad, the hybrid circuit becomes unreliable while driving and could drop below 9 volts, triggering various errors. Even a battery tester might not be a reliable way to check it, I guess.
If you don't drive much then probably best to replace it every 5 to 7 years max. And he does have some interresthing tips on a much cheaper AGM 12 volt battery with a higher capacity!

To get some context, it is useful to view his preceding video, where he contemplates getting rid of his 600 because of the errors generated by the battery problem.

It could have been a costly mistake.

(I have noticed the error I have made with the title spelling - I have asked Admin to fix it)

Thanks for clarifying for the other members. I’ve seen the preceding video, but it’s still unclear whether the new 12-volt battery has completely solved the problem. Time will tell.

I'm afraid it's bad news: