I recently changed the battery on my FX37. I did it myself - got the battery from Walmart. I've done this many times before on my previous Infiniti, Acura, and Honda and never had any problems.

What I started noticing is that sometimes the battery disconnects from the car completely - mostly when the car is parked. I can tell because all my settings get reset, and the clock stops. Sometimes it's a minute, sometimes it's more than 30 minutes. I can tell by how far the clock is from the actual time. It happens when the car is parked usually. Once it happened when I was driving on the highway! The lights flashed, music stopped for as second, and everything went back to normal. Another time it happened in the parking lot, and I couldn't start the car for a minute and no electronics were working. And then a minute later it started with no problems.

Now, all the battery terminals are connected to the battery really tight, so I'm going to claim here that my installation is good.
Therefore, I have 2 possible problems - either the battery is faulty, or the alternator is failing?

Does anybody have any ideas or suggestions on what to do next?

KGBhoy wrote: ↑

Fri Apr 06, 2018 9:24 am

...
What I started noticing is that sometimes the battery disconnects from the car completely - ... Once it happened when I was driving on the highway!

...
Therefore, I have 2 possible problems - either the battery is faulty, or the alternator is failing?

Does anybody have any ideas or suggestions on what to do next?

Wow, that gets irritating real quick, and quite dangerous too!

Did the problems start immediately after the battery replacement? If so, that's where I'd start. I am sure walmart will claim they have to test it first, etc but explain the safety concern.
After that, or simultaneously, check the alternator. With the car running, a good alternator will keep it running regardless of the state of the battery*.

You didn't happen to make any foul connections during the removal or replacement of the battery, something to cause a spark, did you?

Did the problems start immediately after the battery replacement? If so, that's where I'd start. I am sure walmart will claim they have to test it first, etc but explain the safety concern.

Not immediately, maybe a month later.

After that, or simultaneously, check the alternator. With the car running, a good alternator will keep it running regardless of the state of the battery*.

I drive it for hours without a problem. Most of the time it's fine - it usually disconnects when parked.

You didn't happen to make any foul connections during the removal or replacement of the battery, something to cause a spark, did you?

Nope

mac,battery cables can get corrosion INFILTRATED inside the very fine wire they are made up of.It can be bad all the way up the cable SEVERAL INCHES . When cables are removed for Batt. install that DISTURBS the bad wires into a VERY unstable current carrying path. Also many cables now , you've seen'em that are not just a clamp onto battery - but have multiple nuts & bolts , some even got a HUGE fuse in series.Again Batt. change DISTURBS these when corrosion is present and causes these intermittant "PATHS". New cable(s) ?? Cable ends?
Also try to "Disassemble Completely" any nuts, bolts ,fuses etc. & inspect and wire brush/replace'em. Spray battery connection "protectant" IF 'n this is all what it was to help as preventative.

Ok, I'm back to the alternator. Maybe it does it in park because the RPMs aren't where it would like them to be.

Check the belt and that the pulley is still ok. Next time you're in park, engage the e-brake and have it in neutral to see if both idle RPM situations will bring the loss of power.
Or pass by an auto parts store. They should be an Le to test it while installed in the car.

EdBwoy wrote: ↑

Fri Apr 06, 2018 12:41 pm

Ok, I'm back to the alternator. Maybe it does it in park because the RPMs aren't where it would like them to be.

Check the belt and that the pulley is still ok. Next time you're in park, engage the e-brake and have it in neutral to see if both idle RPM situations will bring the loss of power.
Or pass by an auto parts store. They should be an Le to test it while installed in the car.

Sorry, I must have made it confusing. When I say it happens when I am parked, I mean with the engine off. Like overnight or in a parking lot.
It only seemed to disconnect once while the engine was running - on the highway - during a very cold day (around 20 degrees).

Thanks for the clarification. Do you ever use more than one key fob? Do you have any aftermarket audio/security features?

Also, might you have any form of warranty on the vehicle (extended, elite etc)? It might be worth a trip to the dealer to diagnose if one of your power modules is going bad.

So the latest is - I disconnected the battery and cleaned the terminals, then reattached and sprayed with the protector and haven't had this problem for 10 days now. I wonder if my original work was not good after all. Very strange as there is nothing visibly wrong with the connectors.
Fingers crossed there's nothing major wrong with the car.

mac, yup - I've been there - Hope that WAS it and the lasting fix