2008 CX-9 Touring Battery Drain
 

Hello...if the car is parked for 3-4 days, when I try to start it the battery is dead. Something is draining my battery - actually, 3 batteries now.

Is this happening to anyone else?

Glove box light remaining on due to a bad switch? Any other light that is out of sight that could be staying on? If you locate one, see if it's warm when it should be out & cold.

A shop or helpful friend can put an ammeter on a battery lead then remove one fuse at a time to locate the errant current draw. Don't buy more batteries...that's not the problem.

The first thing to do is charge any battery you are using and load test them..
Then by using a Diagnostic Tool check the OBDII diagnostic connector and look for any DTC or pending DTC and also a peak at the monitors.

Your response although says you have tried 3 batteries, means little if first you don't know if the batteries are ok. A new battery or a fully charged battery is not a qualification of a good battery!

There are a few circuits that will draw power so pulling fuses to find which one is drawing power is not really how you do it on newer vehicles. You must measure the ohms and then check the specification for the proper draw or power use of that circuit.
I can save you the time if you are asking how to do this it would be better for you to take it to a shop and at least have them check you battery and charging rate first and then discuss the diagnostic hunt for you power drain. You can expect unless they get lucky and find it right away for at least 2 hour labor charge.

@PTguy @Callisto Thank you the reply. Mechanic kept the car for a couple days, No luck finding the parasitic drain.

I got a tip that the ground connection shown in the pic could have something to do with a parasitic drain. Does anyone know what it's connected to?

https://cimg3.ibsrv.net/gimg/www.maz...eb6e1f43f0.jpg

Grounds like the one pictured or for that matter any ground that is bolted securely without being insulated to form a complete grounding circuit from the chassis, frame and engine do not cause a parasitic drain on a battery in a 12 volt system .

In fact it is a good idea to add several more ground straps and wires to your car to improve the connectablitly of the 12 volt system.
They even have DIY kits to add more ground connections.

I still did not read that the batter was properly load tested? I see that the battery is sold date Nov of 2019 so that means that the retail stocking and manufactures date could be a few months older?

Not to be rude but if your "mechanic" had the car for 2 days and did not find the problem...time to find another shop!

Power drains can be a pain to find. Takes time, patience and a voltmeter.

For someone experienced and more so having formal training in electronics's specifically Automotive Diagnostics it generally only takes no more then an hour to locate at least the circuit that is causing a battery drain. Naturally it is important to have the information on the vehicle you are working to know those systems that do have a constant supply of power to keep them active and then do the math to subtract what they need from what is actually being used from the battery . If it is wires damaged in the system finding those wires is a little more time , i.e. rats or rodents chewing on wires, the protective jacket exposed by age,weather,, or routing etc. This does take in most cases about an additional hour to narrow it down to a section of the damaged harness effected. The big part is knowing how to use the Digital volt ohm diagnostic tool. I know we all like to think we know how to use them but it has been my observation helping my friends with their cars that most only know a few of the several of setting on even the simplest of electrical voltage measuring tools,

Forgot to start the ###### car yesterday AM, and battery was drained this AM. AAA just jumped it again. The work-from-home everyday thing is messing-me-up. Need to get in the habit of starting it everyday and letting idle 20-30 mins.

@Callisto Thanks again for chiming-in. To clarify my question about the ground. I didn't ask if the ground could CAUSE a parasitic drain. I asked if anyone knew what components are connected to the ground in the pic.

Also the battery, any battery, was ruled-out a long time ago. In the past several months, I've been through two (2) brand new Bosch batteries from Pep Boys - both under warranty from a 3rd Bosch that lasted under 3 years. After being jumped, the Bosch batteries did not hold a charge anymore. The current battery's been jumped three (3) times, including today. Tomorrow the car will start. If I wait till the day after tomorrow, the car will not start and the battery will need to be jumped again.

I'm going to post on Nextdoor.com and network myself to a specialist...

You ain't lyin' my friend...and I don't have either of those three (3) things right now. On the bright side, I'm finally getting some value out of the AAA membership. :-)

I understood what you asked but thought you would simply go and follow it back to the other end. That large a cable (4,6 or 8 gauge ) will generally connect to the block, the frame or a starter? Many vehcls come factory with 2 grounding cables.

Just because you are trying 1-3 or 100 batteries if they are not tested first then 1-3 or 100 could all be possibly bad. That is why I keep recommend suggesting and posting about load testing them.. the term a battery will not hold a charge is somewhat inaccurate. The voltage on a bad battery can still in most all cases be charged to 12 plus voltage. But if the battery amps are not there to support the voltage then you have a bad battery. BTW many batteries are not completely NEW unless the supplier specifically say 100% . Most batteries these day even from the top brand are made from recycled parts winch include the core. I also mention shelf dates, retail sale date vs actual manufactured date . Just because you purchased a battery today may not mean that it has only been around for no more then 6 mos from the actual manufactured date. And many battery supplier will service their account by battery rotation. This mean that they will find batteries that are 6 mos or older by the generic date could and swap them for a newer date. perfectly ok practice that has been done for decades. They will take the batteries and have them tested. If they are ok then will receive a new date code sticker and back to a retail outlet.


A battery drawing down to the no start level in 24 can easily be traced. That is a big draw. If you keep attempting to start the engine with jumping you are going to be replacing a starter soon. I would at least have a 1amp charger or better an automatic battery charger on your car so the battery will not drain down until you resolve your problem?

I just went out to my 2018 Mazda 3 and fired up the stereo for about 10 minutes. With my sound system it took the voltage down to the point that load testing the battery indicated to charge and re-test. So it is now on the charger for about an hour to restore static voltage to where I can retest the batteries condition. Oh I have 2 ground cables one to body and the other to the wire distribution power block.

I will post the retest pictures later.

This picture is a constant voltage readout in my console compartment.

https://cimg3.ibsrv.net/gimg/www.maz...05d5f64f59.jpg

You can see in the next picture that I have slightly low voltage and the load test indicates the necessary 12 and re-test for battery health.
Oh this OPTIMA battery uses 100% new materials.


The volt gauge is on " display hold" for reference of static voltage prior me starting the test and before I played my stereo.
https://cimg8.ibsrv.net/gimg/www.maz...7c18f5b062.jpg

https://cimg4.ibsrv.net/gimg/www.maz...95aa8d5f9f.jpg

Now receiving low amp charge and indication charging voltage.
https://cimg8.ibsrv.net/gimg/www.maz...3be7587514.jpg

Battery fully charged repeated load test and the results @850CCA good battery.

https://cimg9.ibsrv.net/gimg/www.maz...48516fc027.jpg

https://cimg2.ibsrv.net/gimg/www.maz...544cacd228.jpg

GREAT news! Thanks for following up with all of us!

Same....
 

I have the same problem. We’re you able to figure out the issue?

Exact same issue.
 

Denise was yours the rear defroster also?

I have a 2017 CX-9 GT, parked it for a week in the summer while I was on vacation in BC, and battery drained and had to buy a replacement at Mazda in Calgary $300+ including diagnosis. Then my local Mazda told me to get a trickle-charger as it's a know problem in my model. And not covered by extended warranty. When I tell people with other brands they think I'm crazy. Never had this with my previous vehicle. Not very happy.

yes so I drive car for 30 minutes every day. Something drawing on battery at night. mechanic confirmed but doesn’t know what.

Alternator
 

Yes it happened on my 15 CX9 it was the alternator. When running the alternator tested fine but when off gave a 4 Amp path to ground.

1--A new battery probably was not needed. A recharge of that battery and finding and fixing the problem is the solution. My 2016 often sat a week, with the original battery, and no problem.
2--Some CX-9s with the toe operated lift gate opener had the wayward electrical drain through that toe operating mechanism. That's the only known problem of this sort I've heard about, and it can be easily fixed. I not the toe switch, then something else as described in the posting above. A trickle charger (the modern name is a battery maintainer) is a band-aid, not a fix.