My new-to-me 2017 V60 almost always flashes a "low battery" warning if I'm in the car with the accessories running but the engine off. I had the battery tested and it's fine, voltage inside the car looks good too. Is this a common issue?

 

The battery light comes on because the battery is not charging. It is completely normal. Your car is saying hey, don't run me until I die. Your car should turn off on it's own before this happens anyways.

 

See, that's the strange thing, it pops on almost immediately. Id say it appears within a minute if I have the accessories switched on

 

That is completely normal. That lights comes on when the car is powered on, but not running.

 

Interesting. I'm just investigating the same thing in my 2015.5 V60.
I'm seeing the voltage in the car (measured at center console cigarette lignter) drop fairly steadily from 12.7 to 11.7 V. This is odd for a good battery.

What is interesting in my battery tender does not change to show as charging (green LED turning red). Normally this happens the instant any load is put on the battery. solid green light means its at float voltage but the voltage in the cigarette lighter is well below.

Thinking there may be high resistance somewhere. I'm going to clean the battery posts and check the wires at the crimped ends.

 

What battery is in your car? 92- T7 or a 48 H6?

The 48 H6 will give the ""low battery" warning if I'm in the car with the accessories running but the engine off." as another has posted.

The solution is a 92 T7 or 30772236 Volvo battery. Auto parts stores sell the same exact battery as the Volvo battery. It just has a different sticker on it. The diehard T7 is an example (of the same exact battery that Volvo sells as a 30772236) Make sure it has the made in Germany sticker on the t7 and it will be the same as a "factory volvo " battery. I don't know what it is with the german battery - but I had to warranty out several H6's (that were install according to the interstate catalog) to t7's to eliminate the new "low battery" message that appears after sitting with the radio on and the engine off.

 

I have been having the same issue on my 2015.5 V60 R-Design. I will get a "low battery" warning on the screen if I drive it only a short distance, despite having a brand new battery. It's okay if I drive it for a while, but just driving it around town will make the message pop up, and if I don't drive it for a long drive, the car will fail to start. Dealer checked out alternator and wiring and said all is in order. This did not happen for the first 4 years of ownership. Bummer as it makes the car unreliable...

 

I also have a 2015.5 V60 R-Design with a new battery that constantly throws the low battery error and won’t start without a boost. I had the car evaluated by a dealer and they installed some software updates but problem was not solved. Is there a bulletin or something that the dealer can review? Great car but this is intolerable.

 

If it won't start without a boost (I trust you mean having to use jumper cables to get the engine to spin over fast enough to start) - Either the battery is bad or there is a large parasitic drain on the system. Does it start 1/2 hour, hour, 3 hours later and not start the next morning? What"s the pattern?

 

The car will restart soon after being jumped but, yes, sitting overnight will cause the problem to recur. The battery is 3 weeks old and was checked by the dealer 3 days ago. It is a top of the line Optima. The parasitic drain possibility occurred to me as well so I made sure no charger is inserted anywhere before the last recurrence. I don’t know where any other drain could occur. Car is bone stock as delivered.

 

If convenient - park the car and disconnect the battery. Reconnect it in the morning. If it's not weak there is something using current with the car off.

If it's weak you have a bad (new) battery.

I would only use what Volvo puts in which is a H7 size 92. I've seen Volvo install AGM batteries in that size as replacements. At my shop the Interstate driver would bring me batteries (a mt92 T7 for your car), and put interstate stickers on them. His next stop - to the Volvo dealer where the same batteries get Volvo stickers. Auto zone sells the battery below - which is the same exact battery (if it has a made in germany sticker on it) as Interstate and the 30772236 Volvo battery.