Is my car battery dying ?

[Krogen]

Before you replace the battery, clean the posts and the cable terminals and try again.

Then if disuse is the case, keep it on a battery tender. I have learned that many newer cars pull a constant low level current. Let them sit for a while and they discharge the battery. Hence the battery tender.

 

[PatriotX]

Had a BMW a couple of years back that ate a $600 battery that was only 2 years old.

Dealership explained that the ‘smart’ alternator freewheeled during coasting to save a fraction of a MPG for overall CAFE average benefit.

This subsequently put more strain on the battery, requiring deeper discharge and higher charging rates under load.

So batteries became an ANNUAL expense, at $600+ a whack, to gain a tiny fraction of MPG.



I no longer own that vehicle.

 

[Ματθιας]

I wouldn't waste a day either. Instead, I drop off the vehicle, hop in the loaner they have waiting for me and go on my way until they are done with my vehicle. Since my dealer is about 10 minutes from my house, it's not much of a waste.

That wasn't my point.

 

[Imissedagain]

OK, I've gotta ask: What's a DCM?

Yet another reason to keep our older cars.

Data Communications Module,
which can cause a DCD.

 

[Oldengineer]

This thread reminds me of “defeat devices “. The idea is to take advantage of the fact that the hood is open when a vehicle is certification tested. Hood open, no charging from alternator = higher FE and lower emissions! Close the hood….well, everything is working again. Extremely illegal and frowned upon by EPA/CARB.

 

[Ματθιας]

For my F150 351M, I have an AGM from Napa. I got the biggest highest capacity battery that would fit. I do run H4 headlights and they have a big draw, so it's nice to have. H4s are a huge improvement over the old sealed beams! The alternator is upgraded, but I don't remember the spec.

In the CrownVic, a red top Optima from autozone works. Finding an alternator (after the OE one was getting iffy and killed the last battery) was a pain. I got a made in china one from NAPA that I had to buy out right, no core charge, but it works.
I had the OE one rebuilt to police interceptor spec and is a spare.

 

[LVSteve]

For my F150 351M, I have an AGM from Napa. I got the biggest highest capacity battery that would fit. I do run H4 headlights and they have a big draw, so it's nice to have. H4s are a huge improvement over the old sealed beams! The alternator is upgraded, but I don't remember the spec.

In the CrownVic, a red top Optima from autozone works. Finding an alternator (after the OE one was getting iffy and killed the last battery) was a pain. I got a made in china one from NAPA that I had to buy out right, no core charge, but it works.
I had the OE one rebuilt to police interceptor spec and is a spare.

A standard H4 55/60W bulb draws no more current than a standard US halogen sealed beam unit of the 90s. I went down this road with the '96 Firebird I bought when I got here. I fitted a pair of Cibie Z-beam headlights with 55/60W H4 bulbs. The distribution of light was so superior to the hot and dark spot sealed beams it wasn't funny. Small wonder US cars require airbags when you cannot see where you are going.

Now, if you've got 80/100W or 90/130 H4 bulbs, then you do have more draw, but no more than I used to have in a four headlamp equipped car in Europe. You just need to ensure you use the proper wire and relays. I noted that the USDoT regs actually limit the wire gauge for headlights. They went to all that trouble to stop people using more powerful lights whe nwhat they should have done was mandate better headlight patterns.

 

[pasound]

My mechanic sells Die Hard.

 

[Ματθιας]

A standard H4 55/60W bulb draws no more current than a standard US halogen sealed beam unit of the 90s. I went down this road with the '96 Firebird I bought when I got here. I fitted a pair of Cibie Z-beam headlights with 55/60W H4 bulbs. The distribution of light was so superior to the hot and dark spot sealed beams it wasn't funny. Small wonder US cars require airbags when you cannot see where you are going.

Now, if you've got 80/100W or 90/130 H4 bulbs, then you do have more draw, but no more than I used to have in a four headlamp equipped car in Europe. You just need to ensure you use the proper wire and relays. I noted that the USDoT regs actually limit the wire gauge for headlights. They went to all that trouble to stop people using more powerful lights whe nwhat they should have done was mandate better headlight patterns.

I'm running 55/100s. Everything is upgraded, including wiring. I do love my Hella H4s - everything reflective glows!
I also run a stereo system that draws a lot of power.

As an aside, if you could see the super bright, high powered headlights folks on ABQ streets are running. It's lawless, LE can't do anything about petty crime much less headlights or wiring.

 

[jsfricks]

AMG batteries are designed to sit for awhile and still work. Make sure you don’t have something pulling it down such as a camera, cell phone charger or something else. I always use AMG batteries and the one in my truck did this but I was leaving my camera on or cell charger. Now I keep a trickle charger on it with it parked in my driveway since it gets very little use now. Get a small one and the hood with close or almost close along with an extension cord. That’ll keep it charged up.

 

[GypsmJim]

An AGM battery is a poor choice for a car where the replacement spec was for a lead acid battery.The charging system can destroy it if it was not setup for AGM.

We have 2 new cars within 2 years old and we often go on vacation for a couple of weeks. No issue when we return.

Cars may have a parasitic drain, but not nearly as bad as an RV. Our RV battery is disconnected when not in use. Regardless, we can easily go for a month and it will still work.

My old car is used about 100 miles a year. Never need to recharge the battery, even after a Winter of sitting. My last DieHard lasted 29 years. The NEW Diehard didn't go more than 2. They ain't what they used to be.

We stopped buying DieHards when they went to ****. The last one was DOA and they would not honor the warranty because they said the car's alternator was bad. My multi-meter proved them wrong, but they would not agree.

The best batteries NOW are Auto Zone Duralast. Second best (believe it or not) are Wally cheapies.

My suggestion is that its simplyba bad battery and needs to be replaced.

 

[LVSteve]

The best batteries NOW are Auto Zone Duralast. Second best (believe it or not) are Wally cheapies.

My suggestion is that its simplyba bad battery and needs to be replaced.

It's done, and I went with the Walmart battery. Same spec as the BMW OEM piece, 90 Ah, 900CCA. Car is a diesel with a stop-start system, although I have it disabled. Wallymart was $179 plus tax, Autozone and O'Reilly started at $244.

Now I need to find somebody with the OBD2 device to "register" the battery.

 

[swsig]

A timely thread for me. Two days ago, I went to take my Lexus RX450h hybrid SUV to get its state inspection so I could renew its registration. The dash lit up, but it wouldn't start, so I decided to recharge the 12 volt battery with my trusty 45 year old Schauer charger. To avoid any problems from accidentally zapping the 450h's very complex electrical system, I decided to disconnect the battery, located in the trunk. Now Lexus did not make battery access a priority on the 450h. I had to: 1) Remove the trunk carpet mat, 2) Raise and fold the hard deck and fasten it to the rear seat with a hook, 3) Remove the spare tire cover, 4) Remove three plastic pop rivets from the battery cover, 5) Remove the battery cover, 6) Disconnect the battery, being careful not to dislodge the vent tube. I charged it for 45 minutes until the charging rate stabilized. My voltmeter showed 12 volts, close enough for me. Before I buttoned everything up, I attached a pair of quick connect leads to the terminal clamps that allow me to plug in my low-amp battery maintainer from outside the car. Now I can easily "top off" the battery as needed. I then charged the battery for a couple of more hours using the battery maintainer.

Yesterday, I went to get the inspection. My 450h fired right up and ran perfectly. I drove the three miles to the inspection station, and got right in, as there was no one ahead of me. The inspection went quickly, and... it failed! I still had to pay $25 for the inspection. It turns out that the car's OBD computer has to reset after a battery disconnect, and won't engage the inspection station's emissions computer until the car is driven about 30 miles following the reconnect. Nowhere in the owner's manual (yes, I read the owner's manual) was this mentioned. I learned it from the inspection station guy.

Today, I cruised up and down local highways until I'd put 35 miles on my 450h and returned to the inspection station. This time it passed! Even better, I didn't have to pay for the re-inspection. But what should have taken one afternoon had taken three days. Moral: If you live in a place where OBD computer emission inspections are required, make sure your battery is up to snuff before you go.

 

[BC38]

This thread reminds me of “defeat devices “. The idea is to take advantage of the fact that the hood is open when a vehicle is certification tested. Hood open, no charging from alternator = higher FE and lower emissions! Close the hood….well, everything is working again. Extremely illegal and frowned upon by EPA/CARB.

Sounds like a VW diesel thing, maybe?

 

[Ματθιας]

An AGM battery is a poor choice for a car where the replacement spec was for a lead acid battery.The charging system can destroy it if it was not setup for AGM.

My two vehicles 25+ and 45+ years old with AGMs. They came stock with flooded lead acid batteries and stock charging systems, well the truck has an upgraded alternator - both are doing fine and are about 3 years old.

AGM batteries are better in every way than a flooded lead acid battery and they DON'T LEAK!

 

[S-W4EVER]

... AGM batteries are better in every way than a flooded lead acid battery and they DON'T LEAK!

I hope you’re right because in the past couple years I upgraded the batteries in my wife’s car and my truck to AGM’s. The factory batteries in my Ram were still good but they were five years old and that’s all I got out of its predecessor so I replaced them (rather than deal with it in the dead of winter).

I bought them at Les Schwab, not the cheapest but they stand behind what they sell and that means a lot to me.

 

[LVSteve]

FWIW, unfortunately many forget Basic Battery Maintenance. Wipe the Top of the Battery Clean as build up can link + to - terminals resulting in discharge. Keep terminals and connecters clean and slightly greased to prevent corrosion. Many “ newer” vehicles have rubber covers attached to cables. Make sure you inspect them and clean as needed and cover terminals.

The battery for this car lives in a compartment in the trunk. It is spotless in there.

My other diesel also has a well protected battery. It lives under the front passenger seat!

 

[Autonomous]

Some vehicles with deeply buried batteries have lugs for jump starting. These lugs can be used for charging as well.
Check the owner's manual.

 

[JMD999]

Your battery is probably going to die very soon. I'd replace it ASAP.

I buy the biggest battery that will fit the "tray" at Walmart.
If the tray is too small modify it.

 

[pantannojack]

After reading most of the above: I just want a truck, not a top of the line fighter jet.

52 GMC
74 Toyota Land Cruiser
72 F150
66 Chevy
86 F150
91 E350 (460ci 12 MPG)
96 Bronco