Battery flat

[Kuba77]

Hello everyone.Few months ago I change Battery for new one.(I thought it’s that issue  why I can’t start my Lexus.Today I thought maybe Battery in key gone so I change Battery for new one and it’s the same problem .Looks like Battery it’s flat again!Sincefew months I have problems with my radio on my Lexus .Sometimes plays sometimes not.Can it be reason and makes my Battery flat?.Something recharge my Battery in my car.Has anyone had sim Iliad problem on his Lexus is 300h.My fiance she use a car once a week (Winter time more often ).For any advice I predicate it .Regards Kuba

[LenT]

34 minutes ago, Kuba77 said:

Few months ago I change battery for new one.(I

If your Battery is only a few months old, then it will be under warranty.  Take the car back to where you bought the Battery and ask them to check it.

It’s always possible that it has a fault, and you probably don’t know how long it’s been standing around before you bought it.

The seller should be able to check the Battery condition and the charging rate, to see if it’s a fault with the car’s electrical system.  They should also be able to detect if you have a drain on the electric system.

Remember, it’s a brand new Battery.  Presumably, you didn’t have this problem with your previous Battery, so the problem is theirs not yours.

[Kuba77]

Thank you LenT for advise .I will do that as you said .Thanks👍

[David lings]

Kuba

You could have a number of issues that need checking in addition to a defective Battery.

l had similar problems with a recently procured Lexus.

l found the Lexus dealer totally useless.

l would suggest you have the Battery checked for a defective cell but also get your alternator checked and what your parasitic loss is.

Do all these and you will get an indication as to where your problem lies.

Good luck.

David

[Thackeray]

On 10/22/2023 at 8:33 PM, David lings said:

l would suggest you have the battery checked for a defective cell but also get your alternator checked and what your parasitic loss is.

Just to clarify, the Lexus/Toyota hybrid system doesn't have an alternator. The 12v Battery is charged from the hybrid Battery whenever the car is in the Ready state. It isn't necessary for the engine to be running, so long as it's in the Ready state. I'm assuming a 2006 GS450h is the hybrid model.

[David lings]

I wired a voltmeter into my is300h there was slow discharge unless the engine was running.

Once running the Battery voltage rose to about 14v until charged then dropped back a little.

With the car in P or N the voltmeter read about 12.8v dropping to 12.2v 30mins after switching off and everything shutting down.

l had a very reasonable parasitic loss.

These checks l found necessary as Lexus were hopeless and it help me prove my unreliability was more Battery related than ‘hybrid’ or whatever .

Lexus just kept saying ‘battery not fully charged due to too many short runs’.

When asked what Lexus defined ‘low Battery and short runs’ as they were unable to say.

I did 35miles to my dealer and it was suggested that was sort.

So the next time l did 200 miles and asked if that was still a short journey.

The above checks are the sort of checklist l think Kuba needs to help find his problems if he has not already got them sorted.

David