Car battery

[Abung]

I have a is 300h Lexus.

I am not able to start. It shows red light for Battery. I have charged Battery and start is fine. But the day after not start again!

What is the problem with car?

Is it Battery itself need to replace?

Or alternator? Or something else?

[NemesisUK]

Hybrid cars do not have an alternator, the 12v Battery is recharged from the traction Battery.

How long did you run the car after starting? What is the state of charge of the traction Battery?

If the 12v Battery is the original supplied when the car was new it may well need replacing.

[ColinBarber]

Assuming you fully charged the Battery then it clearly isn't holding a charge if it doesn't last a day unattended and therefore needs replacing.

[flookyk]

1 hour ago, Abung said:

I have a is 300h Lexus.

I am not able to start. It shows red light for battery. I have charged battery and start is fine. But the day after not start again!

What is the problem with car?

Is it battery itself need to replace?

Or alternator? Or something else?

How exactly have you charged the Battery?

[Herbie]

Before you spend any money on a Battery I suggest you first check the voltage with the car in READY mode, which should be around 14.5V.

It would be unusual for the DC/DC converter (the hybrid equivalent of an alternator) to be faulty and I agree that the Battery is the most likely culprit, but it's definitely worth a check first.