[flycaster]

I have a 2013 ATS Lux 2.0t (32K miles and like new) for which I want to find out if I will need a new battery. The car is starting alright, but the volt meter on the dash is reading around 13.8-13.9v when starting the car. If I recall right, the car generally started at 14.1-14.2v. When using a battery tender the night before, the starting volts would read around 14.2v. I know the car is 9 years old and a new battery probably is in order, but I'd like to know how this data is interpreted?

Assuming the recommendation for a new battery, this is something I would have DIY'd in my younger years but now have to have someone do it for me. So, who? The stealership for around $380, or a local mechanic with a reasonably good rep, or something like Firestone...both of which will be around $50 less.

 

[Sydtron]

When you are driving, what is the battery charging at? When the battery is wearing out, that charging voltage will be higher (>15V). You could also have the battery tested at just about any auto parts store to see for sure. Also, are you located where you get cold weather? Below freezing starts is where you will really see the battery start to struggle, but if you never see cold you could probably get a little more life out of it. As for getting a new one, I'd just ask your dealer if they could match the price of a competitor - they might just go for it!

 

[flycaster]

When you are driving, what is the battery charging at? When the battery is wearing out, that charging voltage will be higher (>15V). You could also have the battery tested at just about any auto parts store to see for sure. Also, are you located where you get cold weather? Below freezing starts is where you will really see the battery start to struggle, but if you never see cold you could probably get a little more life out of it. As for getting a new one, I'd just ask your dealer if they could match the price of a competitor - they might just go for it!

When driving, the battery is reading around 13.8-9v, never been higher than 14.2-3v. I'm in Florid-duh where temps range from the 60s into the 90s. So, what you are saying is that I should start considering a new battery, if while drivng, the battery start to charge in the high 14's? Thanks for the buying advice.

 

[Submariner409]

A fully charged "12 volt" lead-acid battery will show 12.6 volts when disconnected from anything (the vehicle) for a half hour. Anything above 12.7 volts is system voltage with the engine running, and with today's smart charging systems that voltage may vary from the low 13s to maybe 14.8. Amperage is also varied to charge the battery and carry electrical loads but our vehicles do not have an ammeter readout.

An AGM battery will read .2 to .3 Volts higher than a lead-acid will.

Lead-acid, AGM, and gel batteries all have different charging protocols. One charger DOES NOT fit all ..............

Yes, a Battery Minder will hold the voltage at about 13.2 with literally NO amperage input so as not to overcharge or boil the battery. Disconnect the leads and, if left alone, the battery will drop to 12.6 in a few minutes.

Remember that the DIC battery voltage with the Key:ON is somewhat inaccurate due to other loads that come on with the key ON. Posted voltages are measured with a good VOM which presents no load and high resistance to the battery.

 

[Sydtron]

When driving, the battery is reading around 13.8-9v, never been higher than 14.2-3v. I'm in Florid-duh where temps range from the 60s into the 90s. So, what you are saying is that I should start considering a new battery, if while drivng, the battery start to charge in the high 14's? Thanks for the buying advice.

I'd get it tested next time it is convenient, but you should be able to keep rolling with it. When my battery was starting to get weak (after 7 years of northern climes), it would charge at 14.8V or higher (cold days saw above 15V) - a battery test confirmed that I should change it as well. I never had any issues, but chose to replace it out of caution.

 

[flycaster]

Hey guys, appreciate your inputs. From what I can gather, I think I can assume that although this is an old battery, it still seems to have some life in it as it still charges in the 14v range and there doesn't seem to be any power problems within the car's functioning.

BTW, just out of curiosity, are you the Submariner that I remember from either the BMW or Mercedes forums I used to belong to several years ago?

 

[FuzzyDice]

Hey guys, appreciate your inputs. From what I can gather, I think I can assume that although this is an old battery, it still seems to have some life in it as it still charges in the 14v range and there doesn't seem to be any power problems within the car's functioning.

BTW, just out of curiosity, are you the Submariner that I remember from either the BMW or Mercedes forums I used to belong to several years ago?

If the battery is original I strongly recommend changing it. They do not last forever and you are not doing your alternator any favors. Keep in mind your car has 20+ modules, and if cranking voltage drops below 9.5V or so, you can have issues with modules refusing to boot.

14V on an AGM battery is actually quite high. Anything above 15V causes the battery to fail. Make no mistake - its normal to go to 14.4V in the car, but for reference, my car is routinely charging at 12.2V, and rarely goes over 13.8V.

 

[rsingl]

Like Fuzzy, I often see my ATS at 12.2 volts because it stays on a maintainer much of the time since primary driver Anna is now at college on the west coast. So I drive the ATS often enough to keep it healthy but much of the time it is on a Ctek maintainer which keeps the battery fully charged so the GM "economy" mode kicks in removing much of the typical alternator drag. It will briefly jump up into the 14 volt range when decelerating to a stop which is another part of the fuel saving strategy-using otherwise wasted engine motion.

And I would replace your battery given its age unless you are about to trade your car in. Even though a well cared for AGM battery can last a very long time, it won't last forever and the hassle of a suddenly dead battery is the type of "expense" I avoid when possible. If I wanted every car trip to be an adventure, I would move to the deepest and darkest part of the African Congo. Since I don't, I keep my cars well maintained to reduce the odds of unexpected excitement.

Rodger

 

[flycaster]

If the battery is original I strongly recommend changing it. They do not last forever and you are not doing your alternator any favors. Keep in mind your car has 20+ modules, and if cranking voltage drops below 9.5V or so, you can have issues with modules refusing to boot.

14V on an AGM battery is actually quite high. Anything above 15V causes the battery to fail. Make no mistake - its normal to go to 14.4V in the car, but for reference, my car is routinely charging at 12.2V, and rarely goes over 13.8V.

Interesting. My dash's voltage has always been around 14.1...even when new. Don't believe I ever saw it go into the 12's??? Yeah, it is old and I should be looking to replace it as I plan on keeping this great car.

 

[Submariner409]

BTW, just out of curiosity, are you the Submariner that I remember from either the BMW or Mercedes forums I used to belong to several years ago?

Nope. Submariner409 is a play on the hull number of the first diesel boat I served in back in the late 50s. USS PIPER (SS409). My avatar. Did a full 30 year career in subs, sub staff, shore duty and Fleet Reserve. Main Power Electrician (EMFN/EM3(SS)) and Operations/Navigation (QMCM(SS)(DV)).

 

[flycaster]

Thank you for your service. Maybe, then, I recall you from my earlier days on the Caddy forum when I first got the ATS?

 

[FuzzyDice]

To add on here, this battery is easy to DIY.

Interesting. My dash's voltage has always been around 14.1...even when new. Don't believe I ever saw it go into the 12's??? Yeah, it is old and I should be looking to replace it as I plan on keeping this great car.

The car has a current sensor monitoring the health of the battery. It sees the battery is towards its end, and it's charging more to compensate. Do not be afraid to DIY this battery. You just remove and replace as always. The trunk interior comes out easily too. You will notice after a week or 2 on the new battery, the car will realize it has been replaced and your voltage will steadily drop. Make sure to use the proper group AGM battery as a replacement.

 

[flycaster]

To add on here, this battery is easy to DIY.

The car has a current sensor monitoring the health of the battery. It sees the battery is towards its end, and it's charging more to compensate. Do not be afraid to DIY this battery. You just remove and replace as always. The trunk interior comes out easily too. You will notice after a week or 2 on the new battery, the car will realize it has been replaced and your voltage will steadily drop. Make sure to use the proper group AGM battery as a replacement.

I don't know, FuzzyDice, but in the old days, it would have been a no-brainer to peel back the trunk lining and replace the battery...at a big $ savings. But, now at 84 and retired, and although I'm in very good shape, I feel that I've long paid my DIY dues and can afford the luxury of having someone else do the work. However, I would like to know that when I do have the battery replaced, what should be done in order to protect the car's settings while the battery is out of the car? Thanks.

 

[FuzzyDice]

I don't know, FuzzyDice, but in the old days, it would have been a no-brainer to peel back the trunk lining and replace the battery...at a big $ savings. But, now at 84 and retired, and although I'm in very good shape, I feel that I've long paid my DIY dues and can afford the luxury of having someone else do the work. However, I would like to know that when I do have the battery replaced, what should be done in order to protect the car's settings while the battery is out of the car? Thanks.

If you have an onstar battery backup, it should be disconnected before changing. But thats it!

 

[flycaster]

If you have an onstar battery backup, it should be disconnected before changing. But thats it!

I'm not sure if I have the On-Star battery, but don't think so. How can I know?

 

[rsingl]

You won't need to back up any settings but the throttle plate position learn MUST be done. If a Cadillac or GM dealer does the replacement, they should take care of it. Otherwise the short and simple procedure is in your owner's manual and it doesn't even require opening the hood.

The express up feature on the windows may also need to be relearned but that is also in the manual. All other settings are retained.

Do NOT neglect to do the throttle plate relearn immediately after replacement. Ignoring it can result in a no start condition or a CEL within a few miles after the engine starts. Even if the engine appears to be running OK, rest assured that the sensor calibration is NOT optimal and this procedure must always be done after a battery is replaced.

Rodger

 

[flycaster]

Would have never thought of checking the throttle plate relearn...Thanks for the heads up.