Hi.
I had my volvo 2018 v90(Cc) showing start stop error on old support battery. I was recharging it and at some point my volvo was even showing start stop enabled (green icon) for a second after the car was starter. I wanted to give it a chance and continued driving to allow it to load fully. But it became smelly after long ride and I figured out eventually that it is the batter that smells sulfur after longer charging.
So I replaced it.
I bought a news car battery of the same size and the same parameters (180A, 12V, 10Ah, AGM), I poured the acid inside and after minutes I checked that it has 12.8V. I've connected everything and started the car.
But to my surprise my car is now still showing "start/stop service required".
I am out of ideas. What is going on? How do I proceed from here?

I'll be very thankful to all suggestions.

edit: The warning message is not showing anymore today but the gray, crossed out "A" icon is shown.

 

I'm at a bit of a loss. I thought the Volvo 12 volt factory-installed battery is maintenance free. You purchased an "identical" battery and "poured" "acid inside"?

From what I understand, a failure of the stop/start battery will only prevent the car's stop/start function from working. I own a 2020 V90 and the car's main power source is the large battery in the trunk.

Regarding the charging of the stop/start battery, while driving, the charging process depends on driving conditions. If you're driving a high-heat environment, with the AC on high, or in a very cold environment, with the heat on high, I've found that the stop/start battery doesn't recharge very quickly.

 

The little start/stop battery is at the bottom of the charging order and in our experience the error can take a few days to clear unless the dealer does it in the computer. Agree w/prior comments. Proper replacement is drop in no need to add acid or water.

 

Stop start will only work if the large battery in the boot is above 85% charged. Had a similar problem with my 2019 XC60, Volvo put it on charge over night & my stop/ start works perfectly, but now I’m only making short journeys & aircon, radio & other electric stufff is being used stop/ start not working.

 

Under normal circumstances, I do not believe your primary battery should discharge are your mentioned. However, the much smaller stop/start battery is more prone to discharge and, as a result, will prevent the stop/start feature from working.

Regarding your primary battery discharge, IMO this is something that should be looked at by a technician. You may have a peracetic draw, a faulty alternator or a battery on its way to needing replacement. From what I recall, I believe the original Volvo primary batteries have a useful life of 4-to-5 years, on average. I've heard of people needing to replace their battery after only 3 years, while I've heard of other instances where the battery can last from 5-to-7 years. I believe it depends on driving habits, the climate your car typically drives in, the features used in the car, etc.