car battery problems - help please!

[ProximaCentauri]

Citroen C4 Picasso 2016 model.

Purchased it in 2021, not sure what battery was in it (never checked). Start-stop system never worked while I had it.

4 months ago, car wont start. Had it towed to a garage. They ran diagnostics and said, battery at 16% health and replaced it with a new EFB Start-Stop battery (Napa AFB096N). They also said the old battery was a non start-stop battery.

For 1 month after installation of new battery, start-stop was working on my car. Then, start-stop function stopped working but rest was fine. And 2 days ago, car wont start again.

Tested the battery with a multimeter and it shows that battery is completely drained. It still powers some lights like the wing mirror lights. Also tried to charge it with a battery charger which showed full after an hour of charging but multimeter shows its empty.

I would really appreciate any thoughts on what you think is going on. Did they install the right battery for my car? Should they have registered or coded the battery on installation (dont know if they did it).

[RichardW]

Welcome along.

What sort of no- start condition do you have? Is there any response at all to the start button?

[myglaren]

Did they test the alternator? Sounds like the charging system is faulty and needs investigating.
If you have access to a charger, give it a good charge, 48 hours on a trickle charger should put it right then keep an eye on it.

[ProximaCentauri]

Welcome along.

What sort of no- start condition do you have? Is there any response at all to the start button?

Well, as soon as I open the driver side door, the alarm goes on. It throws a few alerts on the dash board (engine fault, check parking brake etc) and then not much happens. The car wont start. I then just long press the start button to turn the power off.

When I lock/unlock the car the wing mirrors either dont fold or only one folds.

[ProximaCentauri]

Did they test the alternator? Sounds like the charging system is faulty and needs investigating.
If you have access to a charger, give it a good charge, 48 hours on a trickle charger should put it right then keep an eye on it.

I am not sure what was tested when the new battery was installed 4 months ago. I was charged for 3 hours worth of diagnostics to check everything as it was throwing up all the faults (check parking brake, engine failure etc etc) back then when it did not start.

I used a smart battery charger I bought on amazon and after I turned it on, it started at 80% and in about 20 mins went to 100% and showed FUL. I then left it for about 2 hours and removed the charger. Tested with multimeter and it still shows empty battery. Obviously, car did not start.

Is it worth getting another trickle charger and charging it for long time?

[xantia_v6]

I am a bit confused by "Tested with multimeter and it still shows empty battery." Are you measuring the battery voltage? What was the actual reading?
It is better to measure the battery voltage with some load on the battery, such as switching on the headlights.

[shtu]

Starter for 10 - that battery has a 5-year warranty, get it back to the supplier.

[ProximaCentauri]

I am a bit confused by "Tested with multimeter and it still shows empty battery." Are you measuring the battery voltage? What was the actual reading?
It is better to measure the battery voltage with some load on the battery, such as switching on the headlights.

Well, I'm using a multimeter which is a bit limited in functionality. It has 3 lights green-12.6V, orange-12V and red- 11.5V. When I said empty battery, I was referring to the red light.

When I connected the battery charger, it showed something around 9.6V, if that's helpful.

[ProximaCentauri]

Starter for 10 - that battery has a 5-year warranty, get it back to the supplier.

Sorry, what does Starter for 10 mean?

Yeah, I'll call the garage which installed the battery and tell them I'll bring their battery back. Just I'm wondering whether they will say, the battery drained or died because of some other problem with the cars BMS and not the battery itself?

[myglaren]

Testing the battery as a first step is the right way to go.