XC60 2012 ‘Low Battery’ warning

[Emmadalehols]

Hi all

Newbie here so apologies if this is a common fault I’ve not come across.

I bought an XC60 yesterday on a 62 plate, wanted one ages in White. 20 mins into the darkness and using the lights the low battery warning came on but on putting the multi-tester on at rest, engine running and engine running under load and all readings were good. Alternator isn’t broken by all accounts I can read online

So I’m considering if there’s a common ECU or sub-component fault I’m not aware of that gives false warning notices?

A friend has said on different manufacturers alternators there’s a ‘smart’ function to some alternators where in a certain mode, they could start to fail but present as normal under cold / warm conditions.

I can’t contest the latter comment, but the first scenario returned all good volts. 12.9v no engine on, 14.8 engine on and the same value under load.

So does anyone have any pointers?

Thanks in advance

[Kev0607]

Did you buy it from a garage or private?

It could have been parked up for a long time. The battery may have just needed a drive to charge it up.

[GrahamHR]

Unless you use it every 2 days or so, buy a smart charger. The charging regime on these cars is weird, badly executed.

Since new, I've used a CTEK charger on my V60 Polestar; the only way to prevent a flat battery. 2 days, the indication shows it is partially discharged, 3 days severely so. I also carry a lithium ion battery jump pack if I am away from the charger for a few days

[TimS]

Same with my V70. I frequently get the low battery warning, although it's never had the slightest problem starting. I use a CTEK charger (don't connect the charger to battery -ve) if it's lightly used for a couple of weeks.

Battery is 4 1/2 years old (genuine Volvo), voltage measurements similar to above. There may be some battery monitoring system reset required when changing the battery, although this is not mentioned in the V70's handbook. I simply followed the handbook when I changed mine - if there's a procedure, they should document it.

[Chrisv60]

Are you saying you get a low battery warning with the engine running? If so, that would point to a faulty alternator or charging system.

Otherwise these cars do seem quite sensitive to voltage and flag up battery warnings when the battery is still fine and perfectly useable.

[Ash89]

If the battery is reporting healthy with a battery tester, or the car is starting with ease from cold, the battery could of been replaced but no one reset the BMS system.

You need to reset the BMS using VIDA & DiCE so the car knows it's been replaced.

Or you could try this:
https://www.youtube.com/watch?v=iu9z5m78Szw&t=127s

[GrahamBrown1]

Don’t forget the smaller aux/ support battery can also bring on the low battery message. Be worth checking this also as most are often forgotten about as the main battery still starts the car.