I haven't had the chance to drive it since the temp dropped down to 7 degrees here in Texas last week (should've driven/checked/charged the battery - lesson learned!) and it's been 10 days. Just found out car's not responding to key fob and to make the matter worse I couldn't find the car keys (I never checked if its in there since we bought it used - it might not have been there in the first place) in the regular and the spare key fob to get in, pop the hood and charge the battery...Obviously the worst thing is to have it towed to the dealership but wanted to see if there's anything I can try to do first...

 

If you don't have the emergency key and the battery is dead - A locksmith or car break in service can pry the top of the window frame out slightly (using an inflatable bag is a common method) and use a long tool to pull the inside door handle to open the car.

Or you can simply order an emergency key from the dealer - if you have a few days to wait. The key can be ordered from the VIN and probably proof you own the car.

 

Thanks! We decide to order one from the dealership and see if we can afford to wait a few days for the key or we'll need to call a locksmith...

Also...other than not having the car for use, does it matter if we wait a few days? I mean the longer you wait the less likely for you to bring the battery back to life and still good to go?

 

A charged battery will not freeze. A dead battery will freeze if cold enough and destroy itself. (7 is cold enough, and I'm sure it stayed below 32 for a day or so)

If a battery goes dead and it's not cold enough to freeze - it will still get damaged from being completely discharged and may need to be replaced. If you have stop/start - you will have 2 batteries in the car. The main battery in the trunk and a small support battery under the hood.

When you buy replacements, be sure to buy OEM quality, not the cheapest thing at Walmart. Maybe read this recent post about battery replacements in a 2016 for info. In that car both batteries are under the hood. A battery monitor reset should be done after battery replacement also.

https://volvoforums.com/forum/volvo-...cement-111500/

 

Thanks for the reply. I read/browed the post you included too. I've got locksmith to open the door and I went for a drive on the freeway for 30min after I jump started it. Now I'm charging it with CTEK charger (after 7 hours it still stays on the 3 steps out of 8 steps on CTEK charger). I got the start/stop service required light come on during my drive - does this mean it's dead as you said and needs to be replaced? Does it mean both main n support batteries need to be replaced or only the main one in the trunk?

 

Bought Super Start support battery from O'relly and asked if this is OEM quality he said it should be (?)... Replaced the old one and now is being charged. The main one in the trunk measured 0.98-1 so my question is: Does the main need to be replaced as well or I should wait and see if the new support one/charging solves the problem and start/stop service required light turns off? Also follow up question for the other post you included @hoonk does the reset protocol applies to XC60 too (I used it on our S60 before and it worked well) cuz am not sure if XC has all the same light buttons - guess I'll go see myself too...

 

What is 0.98-1?

If the car has a battery monitor it should be reset when replacing the battery. I've never tried the push button, clasp hands, look lovingly at the sky and say choice words while pushing more buttons method - always used a scan tool to reset the battery monitor.

 

0.98 - 1 volt I think, its very low I know, just wondering if the new support battery may allow the charging to properly charge the main one too as one of the YT videos suggests (but his main one is just a little lower than 12v - like 11.87v or something) or it's sure as dead as can be, time to get a new one as well?

So the question in other words is do you recommend to replace both batteries since they're both 3 years old at least or wait and see if the main one is still ok - sorry dumb layman talking here...

 

Is that the Voltage above 12.6 volts that's being measured with a voltmeter with the engine running? Sorry I still don't understand what that means.

A fully charged battery is ~12.6 volts. With the engine running and a partially discharged battery (you just started the car and used current) a voltmeter attach to the battery (or any B+ source actually) should measure ~13 - 13.6 volts with the engine running. That means the alternator is providing enough current to run whatever the car needs, plus a a few amps to recharge the battery. You will realistically only see the static voltage in your car at 12.2-12.4 volts. And if you want to dig further - use an ammeter with an inductive pickup to see exactly how many amps or milliamps (sp) are flowing in or out - hopefully in when the engine is running.

If you have no start/stop warnings now and the main battery passes a load test after being charged, allowed to sit and has a static voltage above 12v - Then the main battery is still ok. A load tester uses a resistance wire - kind of like an electric space heater - to put a load on the battery and help determine if the battery is still capable of providing xx amps. Fancy battery testers use a capacitance test - some bad batteries can pass that - but no bad batteries can pass a load test. Load testers range from the $20 harbor freight things (I've purchased many of those) to a many hundred dollar snap on tool that includes a printer! (to sell a battery to the next mark sorry - customer.)

 

Yeah sorry I, not knowing better, just measured it w/o the engine running and turned to Vm 20 (following what I saw on that YT video) and it was flowing between 0.98 to 1.02 or something I guessed I did it all wrong...?

And thank you so much!! Never thought to buy a load tester (oh that's what its called) but just checked Harbor Freight and will def get one of those!!

I have 2 chargers one of them is CTEK as mentioned before but I never thought to charge the main one in the trunk. Cuz for some reason I thought charging the support one under the hood is charging the main one also? Dumb I know but the SUV parked in the garage its hard to open the trunk, remove the spare tire to expose the main one in order to charge it. I'll need to figure out a more realistic way to maintain charge that thing after I determine with a load tester if its still good. Will keep you posted. Thanks again and let me know if I'm missing anything else too of course!

 

Oh sorry one more thing I noticed there's load tester for battery (only?) and also for both alternator&battery, should I get the one for both?

 

Yes, both batteries are connected to the same wires - so anywhere you connect a charger to a positive and a negative - you will send current to both batteries.

 

Thanks so much for confirming that. Got the heady duty one from HF and checked the main battery it's about 12.4~5V so it should be good I think?

I don't get the 12v charging fault/start stop service required warning pop up anymore...What scan tool do you use/recommend to reset it now that I've got the new support battery in?