Is a new battery possibly duff?

[A500leroy]

New battery fitted 3 weeks ago from tayna.
Yesterday all the lights flashing on the car and refusing to unlock.

Got to the battery tested it 5v.

Got breakdown man out, tested charging system,all good and no faults logged.

Only thing left, duff new battery?

[anyoldcardave]

It happens.

[tapkaJohnD]

Your battery was flattened by all the light flashing!
Electrical system needs checking. Fault codes?
John

[Scrump]

I would check for a battery drain before condemning a new battery.

[A500leroy]

As said in op, breakdown guy checked fault codes and nothing logged.

[Scrump]

A500leroy said:

As said in op, breakdown guy checked fault codes and nothing logged.

A battery drain would be unlikely to log a fault code.

[richhead]

A500leroy said:

New battery fitted 3 weeks ago from tayna.
Yesterday all the lights flashing on the car and refusing to unlock.

Got to the battery tested it 5v.

Got breakdown man out, tested charging system,all good and no faults logged.

Only thing left, duff new battery?

did he actualy test the charging system or just plug in a code reader, two very different things.
anyway a lead acid battery(if that is what it is) is toast at 5v.

[A500leroy]

plug in a code reader,
anyway a lead acid battery(if that is what it is) is toast at 5v.

[/quote]

[richhead]

A500leroy said:

plug in a code reader,
anyway a lead acid battery(if that is what it is) is toast at 5v.

in that case, you need to have someone check the charging system etc, as there maybe a fault thats killing the battery.

[E-bmw]

A500leroy said:

New battery fitted 3 weeks ago from tayna.
Yesterday all the lights flashing on the car and refusing to unlock.

Got to the battery tested it 5v.

Got breakdown man out, tested charging system,all good and no faults logged.

Only thing left, duff new battery?

Or there is either a parasitic drain or the charging system could still be defective depending on EXACTLY what was tested & how.

In other words, you are still at square 1.

[Car bon]

Agree with the above - I've had a dodgy alternator kill a battery.