2016 Mazda CX-5 new battery needs jump

[Mazdiod2]

Yes, it could be a charging problem. More diagnostics are in order.

AutoZone tested the voltage but they didn't load test it.
I don't have a load tester so I would fully charge it overnight, and then monitor the voltage just sitting for a day or two.

 

[yrwei52]

Yes, it could be a charging problem. More diagnostics are in order.

AutoZone tested the voltage but they didn't load test it.
I don't have a load tester so I would fully charge it overnight, and then monitor the voltage just sitting for a day or two.

OP’s battery was dead and couldn’t start the engine at the first time. He took the dead battery to AutoZone to be tested and it was at 10 V which was worse than the current condition. AutoZone charged the battery up to 100% and OP put it back into the car and started the car just fine for several days even right now other than the voltage has dropped to 10.56 V.

My point is AutoZone definitely had “load tested” the battery after they had spent time charged the battery up and told OP it’s fine. AutoZone has the device to do the load test, and they always do it when you bring the battery in testing the performance. Mind you even a simple battery load tester will show battery voltage, and that’s what the AutoZone did.

 

[GAXIBM]

I think you may have a dead current load of some type in the system. If the battery was at 10 volts and started and came up to 13 then the charging system brought it up from 10 to 13. Sitting is bringing it down. If you disconnect the battery, check the voltage over night or after time passes and it does not drop the battery may be fine. If you put an amp meter between the battery and the battery cable with everything off for a while you should not have any current. Do you have any extra equipment on the car such as remote starter, custom amp, radar detector, dash cam etc it may be creating the drain...

 

[Jmaz]

What? You haven't got a new battery yet? If one wants to solve a problem, then after an amount of discussion, theorizing and conjecture it's best to start by eliminating a questionable variable and use a known good element. Maybe even fix the problem and get on with life. How much of this discussion do you think would occur if the car were sitting in a shop to be fixed. They'd probably swap in a known , good battery if not outright replace it. Guess I'm feeling cranky this morning. Something to do with someone tampering with my Wheaties.

 

[Zach G]

So I bought a new battery, with a 3 year warranty. Swapped it out. Everything is good…gonna take it back to Autozone in a couple of weeks and check the alternator. People talk about how rare it is. But I’ve actually had several batteries throughout the years that didn’t last through their warranty. A couple now less than a year. Not on this car, but others.

 

[yrwei52]

So I bought a new battery, with a 3 year warranty. Swapped it out. Everything is good…gonna take it back to Autozone in a couple of weeks and check the alternator. People talk about how rare it is. But I’ve actually had several batteries throughout the years that didn’t last through their warranty. A couple now less than a year. Not on this car, but others.

Can you get your questionable battery (which brand?) replaced under warranty for free? Some battery warranties are transferable and you don’t even need to provide a receipt.