Brand new car battery keeps draining

[FrugalSaver]

Just had a brand new one (allegedly) put in at the dealership a week ago.  Took car back in for general checkup a week later (tires rotated, etc) and they said i needed a new battery.  I told them I just put in a brand new battery and they said well, something must be draining it so we need to run a $140 diagnostic to help us understand what the problem is

What a mustachian waste of money.  Any thoughts on what the issue could be?  It's never had an issue turning over and all this just started and appears to now be continuing with a brand new battery.

[Syonyk]

Either the alternator isn't charging the battery properly or something is draining the battery.

A small handheld voltmeter/ammeter should help you identify the issue.  Properly charging would be a 14.2-14.7V range when at cruise RPM, and you shouldn't see more than (preferably) a few 10s of mA when shut down, but with modern cars, a few hundred is unfortunately common.

[TomTX]

If you don't have a multimeter, you can get a simple analyzer that lights up LEDs to tell you what's wrong for <$10

Or just go to most auto parts stores (Autozone, etc) and they will test it for free.

[Syonyk]

You can buy a halfway decent multimeter for $10.

[TomTX]

You can buy a halfway decent multimeter for $10.

Absolutely. It will confuse many people.

[Syonyk]

Well, then, pay someone it doesn't confuse $140 to use one.

[TomTX]

Well, then, pay someone it doesn't confuse $140 to use one.

Or just go to Autozone and they do it for you for free.

Like I said.

[Syonyk]

Pull codes, or do an idle current check, charging voltage check, etc?

[Clean Shaven]

You can buy a halfway decent multimeter for $10.

Harbor Freight often has coupons for a multimeter for free. Comes with instructions too.

[BikeFanatic]

You could also bring back the battery and they will load  test the battery . You say I think the battery you sold me is defective.  Some cars have a Bluetooth device and that can drain the battery searching for Bluetooth signal.

[sisto]

It's possible that the new batter is bad, it happens fairly often with cheap batteries from certain chain stores. Also if you have a Batteries + near you they will check the system from free too. If the battery is not sealed you can also check the voltage across each cell with the cheap meter already mentioned. There are 6 cells each should measure roughly 2V. The crappy batteries will typically have 1 dead cell. So by measuring voltage between each cell you will quickly find it.

[Tiger Stache]

Advance Auto will test your system and install a new battery for free. I would suggest getting the battery tested before you follow anything the dealership says

[FrugalSaver]

There was a rusted terminal that they replaced and pinned the blame on

[sisto]

Glad to hear you are back in business, thanks for the update!

[kidmont]

There was a rusted terminal that they replaced and pinned the blame on

I need to test my car battery! If it good then I need to test other things. I thought this battery isn't good and thus damage so quickly. Never thought it could be other problems too!
Now, I am searching a good multimeter. Find this Best Multimeter Reviews 2018 for the money multimeter reviews site. They are suggesting to buy Fluke 115 multimeter. Experience user please share your personal opinion.

[MilesTeg]

Just had a brand new one (allegedly) put in at the dealership a week ago.  Took car back in for general checkup a week later (tires rotated, etc) and they said i needed a new battery.  I told them I just put in a brand new battery and they said well, something must be draining it so we need to run a $140 diagnostic to help us understand what the problem is

What a mustachian waste of money.  Any thoughts on what the issue could be?  It's never had an issue turning over and all this just started and appears to now be continuing with a brand new battery.

Mostly likely it's not a drain, but a charging system that is not working. Go to Autozone or another parts store and they will test it for free.