Battery question

[SFBlue]

Hey Gang-

So, I have a 2012 XC70 T6 that I just picked up about a week ago. Everything was great for the first week, no issues. About two days ago, I went out to start the car and it barely cranked. I got a "Low Battery" message on the dashboard. I made a few additional attempts, and it started, (Barely).

I placed a battery-tender charger on it for about two hours, and then my wife drove it on two short trips. It made it out and back home again, but barely started both times.

I placed the charger on it overnight, intending to give it a good thorough trickle-charge. I checked it in the morning, and the yellow light on the charger was illuminated, indicating that the battery still wasn't charged. (Not sure if it was a poor connection on the terminals; it seemed fine).

So, we took another longer trip (about one hour), and I figured that would be enough to recharge the battery. (Any of my previous cars, an hour was always enough time for the alternator to bring a low battery back to life).

When we left to drive home, the car barely started again. We drove the hour back home, and I placed the car on a the charger again overnight.

This morning I went out, checked the charger, and the light was green. I started the car, and it cranked no problem, everything seemed fine. I let it idle for a few minutes, and turned it off. (I realize that idling it for a few minutes isn't going to charge it, but I figured that if the battery was properly charged now, it should be able to be started and turned off multiple times without draining it).

My wife went to take the car out today, and it started, but the dash screens were flickering as if it was struggling to start. She was leaving to do errands, so I told her to take the BMW instead, so that she wouldn't get stranded in the Volvo I just checked it again now, and it starts, but the battery definitely seems weak.

So, some questions:

1). I'm not sure what I did to drain the battery in the first place... My daughter and I were sitting in the car playing with the Nav and other car features with the ignition on, but it was only for about 10 minutes. I don't think that should be enough to drain the battery, is it?

2). The dealer that I bought the car from said that it had been on their lot for about 45 days... I'm assuming without being driven much. So, maybe this was enough to kill the battery? But if so, why did it run fine for the last week with numerous starts and short trips?

3). Do these cars have notoriously weak batteries, or weak alternators? Is this a known issue?

4). I called my local O'Reilly's Auto parts and the quoted me a price of $120-170 depending on which "Group" battery my car needs. (Not sure what the groups are). They said that if the stereo has a security code they can't install it themselves because they might lock the stereo. I'm assuming this isn't an issue for me, since the stereo is integrated, right? I was planning on installing it myself.

5). When charging the battery, should I have the negative cable on the negative battery terminal, or grounded somewhere? I know this is an age-old argument across the board with all cars, and I have always gone for the direct terminal connection.

I was reading the owners manual, and under Battery Replacement on page 333 it says,

"The negative terminal on the battery
must never be used to connect a
jumper cable or a battery charger. Only
the ground point on the chassis may be
used.
See page 113 for an illustration and additional
information."

I read that, and thought, Oh, maybe that's why my charger isn't working on the battery.

As always, any advice or suggestions would be welcome.

At this point I'm leaning towards just walking down the street to the parts store and grabbing a new battery. But, if I could somehow bring this one back to life by charging it, that would be ideal.

Thanks!

-Angus

[phlegm]

If it helps any, we just replaced the battery on our 2012 T6 about 1.5 months ago. It would appear to take a charge, but ultimately barely work with low battery warnings. We needed a jump start at one point.

Initially suspected an electronics issue, but we wound up going with a new battery, and it has been perfect since.

Seems early for battery replacement, but that was the issue in our case.

[SFBlue]

Thanks for the feedback... So, after reading the instructions saying to hook the negative connection to a ground, not the battery, I tried hooking up the battery tender one more time. This time I got flashing lights on the charger, indicating that the battery was "Sulfated." (Or no good). So, I made a quick trip to O'Reilly's for a new battery. $170 later and about 10 minutes worth of labor and I'm all done. Hopefully the battery solves the issue!

One piece of advice for others... I followed the step by step instructions in the manual for disconnecting the battery, (Ignition off, wait 5 minutes, disconnect negative connection first, etc). One thing I overlooked though, was that I had locked the car after turning it off. (I did this to make sure that the accessories were fully off. It's hard to tell with the keyless start when the dash accessories are fully off).

This resulted in a loud siren shrieking as well as the horn sounding simultaneously, about 18 inches from my head. Lesson learned... leave the car unlocked before disconnecting the battery. Nice to know that Volvo has this security feature though, incase someone attempts to steal the battery while the car is locked.

[brentcd]

Did the O'Reillys do a load test on the old battery first?

Let us all know in a few days if it's cured for you, please.

Also, how many miles are on your car?

[SFBlue]

Did the O'Reillys do a load test on the old battery first?

Let us all know in a few days if it's cured for you, please.

Also, how many miles are on your car?

Hmm, no I didn't think to have them test it. Probably would have been a good idea.

My car has 34k miles on it... So far so good with the new battery, but I'll let you know if that changes.

[budrichard]

Do you have a rear floor cover?
I was having the same problem and one day noticed my rear LED lights were on, I removed the rear floor cover and the car/battery have been fine ever since.
It appears to me that the rear floor cover was keeping the hatch slightly ajar and the LED marker lights on with no dash warning for hatch not closed.
Crazy thing but it happened!-Dick

[phlegm]

Do you have a rear floor cover?
I was having the same problem and one day noticed my rear LED lights were on, I removed the rear floor cover and the car/battery have been fine ever since.
It appears to me that the rear floor cover was keeping the hatch slightly ajar and the LED marker lights on with no dash warning for hatch not closed.
Crazy thing but it happened!-Dick

I do in mine, so appreciate the tip. That cover can indeed slide around, so I really wonder if that scenario occured. So far we've been fine with the new battery, but I'll pay close attention to it. Thx Bud.

[SFBlue]

Do you have a rear floor cover?
I was having the same problem and one day noticed my rear LED lights were on, I removed the rear floor cover and the car/battery have been fine ever since.
It appears to me that the rear floor cover was keeping the hatch slightly ajar and the LED marker lights on with no dash warning for hatch not closed.
Crazy thing but it happened!-Dick

I just bought one, but I haven't put it in the car yet... good to know though!

[toma nova]

I had to replace the battery in our 2010 after about 2.5 years. Similar symptoms - occasional weak start, dash lights flashing. Although still under warranty, a trip to Advance Auto was much easier than the dealer. Replacement has been fine for 2+ years so far.

I chalked it up to TX heat but it may be a combination of poor OE batteries and lots of draw.

Let us know if the new battery has fixed the issues.

Tom