Battery help 2013 LX 570

[neh20711]

Battery help needed.

Replaced the battery a few months ago and it’s run fine.

Now it is completely flat, no charge whatsoever. I used a portable battery to jump it but it does 1 crank and dies again. The old battery had the same issue.
Thoughts or suggestions?

I did do a couple creek crossings a couple weekends ago but drove back a couple hours no problem and have driven the car a few times since then so not sure if it’s the alternator which was replaced 3yrs/35k miles ago at 87k miles.

Thanks!

 

[tbisaacs]

Would definitely have the alternator checked.

 

[bloc]

Yes. And pull the door sill trim to check for water.

 

[KLF]

If all else checks out, look for a parasitic drain on the battery. Lots of YouTubes that show you how.

 

[CanadianRockyCruiser]

Sounds like an alternator to me. Was your replacement OEM? Denso? Other?

 

[neh20711]

Sounds like an alternator to me. Was your replacement OEM? Denso? Other?

2 alternators so early sounds like a deeper issue.

The alternator repair was done by a Lexus dealer with the previous owner

 

[CanadianRockyCruiser]

You could re-charge the battery and start testing fuses for parasitic load...It's possible you've got a drain on-board somewhere.

 

[neh20711]

What is the normal alternator voltage at idle?

I have 13.4

 

[tbisaacs]

What is the normal alternator voltage at idle?

I have 13.4

The answer is: It depends on state of charge, temperature etc. These alternators don't have a fixed voltage regulator.