Parasitic battery drain on 2016 Mazda CX-5 Sport. Looking for help

Brand new to the forum here, seeking help on a problem I have with my 2016 Mazda CX-5 Sport AWD. I'm of the belief I may have a parasitic battery drain. I've done a bunch of troubleshooting but am out of my depth at this point. Here's what I've done so far...

Disconnected negative battery cable and put a multimeter in series to see if their is a draw. Indeed there is, in the amount of about 1.7 amps. Thereafter I started probing individual fuses in the fuse boxes both under the hood and in the cabin near the driver's side door. The only fuse I can seem to find any loss on is number 28 in the fuse box located under the hood, in the amount of .2 mv, which doesn't seem like much to me. It's the only one showing any loss at all, though. I then put my multimeter back in series on the battery and pulled fuse number 28 out. That caused my previous 1.7 amp draw to drop to around .80 amps. So I would say that's definitely part of the issue. I'm thinking there has to be something else too though, as from what I've read the draw shouldn't be any higher than about .50 amps at most when the vehicle is completely off.

So I'm lost in two ways at this point:

1.) Fuse number 28 is AT - transmission control system, ignition lock. So what does that tell me at this point? What do I check next?
2.) Fuse number 28 drops some of the draw, but not all of it/still not to an acceptable level. So something else is clearly wrong, too. As I mentioned though, I can't find any other fuses that have loss. So I'm not sure what else could be causing the draw.

Again, I'm way out of my depth here and have pretty much zero skill in anything related to electronics. So please forgive my naivety and perhaps poor description of what I've done so far. What I've done thus far I've gathered exclusively from internet searches and YouTube videos.

I'd greatly appreciate any insight anyone might be able to offer me here.

Thanks!
 
:
Northeast
:
2020 CX-5 Tour
What is the battery voltage right after shutting down, when the vehicle has been run for half an hour or more? And then what's the voltage after a few hours being shut down?

Also, how long did you wait to get that 1.7A reading and start the testing, after the last 'electrical thing' you did (making the battery connections, closing the door, etc)? You might need to wait up to 20 minutes or so, for all of the computers to completely shut down.
 
Please don't tell me you're still using the original battery from the factory... If so, time to change it

No, this is not the original battery from the factory. I first started experiencing battery issues last summer (summer of 2020). Initially I thought it had something to do with my lack of driving the vehicle as much as typical, as I started working from home due to COVID and was driving very little at the time. When the issues persisted, however, I decided that replacing the battery would be the next logical step, as it was nearly 4 years old at the time. So I had a new battery put in about exactly a year ago in October 2020, by a very reputable local battery shop. After doing that I had no issues for several months, so I figured my issue was solved - I just needed the new battery. A few months back now though, the issues started again. The car will start fine one day, then sit for a couple of days without being driven, and when I go to start it on the third or fourth day it's dead. It will start right away with a jump pack I have, of course, but I can't go on like this long-term. I would think that the new battery should last me more than a year?
 
:
Pueblo county CO
:
CX-5 Sport 16.5 6M
You could install a cutoff switch right on the battery but the cx5 won't be happy.

I think parasitic drains are the new 'normal' on cars with SMART features, remotes, etc. How could the door locks respond to your remote without consuming power while it's waiting?

The battery should be able to sustain for a reasonable amount of time but it can't hold out forever.

I replaced the battery in my 16.5 sport but the new battery voltage starts to drop after a couple of days. I bought a smart battery charger to use once or twice a week, depending on how much I drive. Usually a quick trip to the store isn't enough to completely restore the battery.

Have you read the threads about the rear liftgate module on certain model year cx5s? They have a particularly high amount of parasitic drain and a new module fixes that.
 
What is the battery voltage right after shutting down, when the vehicle has been run for half an hour or more? And then what's the voltage after a few hours being shut down?

Also, how long did you wait to get that 1.7A reading and start the testing, after the last 'electrical thing' you did (making the battery connections, closing the door, etc)? You might need to wait up to 20 minutes or so, for all of the computers to completely shut down.

Voltage on the battery yesterday after it had been sitting a couple of days without being driven was around 11.2 volts, which I know is way too low. I don't have a reading right after shutting it down after about a half an hour of running it, unfortunately. As I just mentioned in my reply to @Silly Wabbit , I have been driving the vehicle very little for the past 18 months or so due to COVID. Typically I would have a half hour commute each way to work 5 days a week. But i've been working from home for 18 months now, so I don't drive anything like I used to. My car can sit unused for days, and then when I do use it it might just be a quick trip to the market a few miles down the street and back. I don't suppose the lack of use is helping matters any, and I have contemplated the possibility of the issues stemming from the fact that it doesn't get driven far enough or fast enough for the alternator to charge it any. The draw I am seeing when I put my multimeter in series has me convinced the issue is deeper than lack of use, however. Perhaps I'm missing the mark though. Like I said I'm a complete amateur here.

The 1.7A reading was observed yesterday right after I disconnected the negative battery and put my multimeter in series. I didn't wait at all, which it sounds like I probably should've. I can try disconnecting the negative battery cable and then waiting 20 minutes or so to test, if you think that will give a more accurate reading.
 
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You could install a cutoff switch right on the battery but the cx5 won't be happy.

I think parasitic drains are the new 'normal' on cars with SMART features, remotes, etc. How could the door locks respond to your remote without consuming power while it's waiting?

The battery should be able to sustain for a reasonable amount of time but it can't hold out forever.

I replaced the battery in my 16.5 sport but the new battery voltage starts to drop after a couple of days. I bought a smart battery charger to use once or twice a week, depending on how much I drive. Usually a quick trip to the store isn't enough to completely restore the battery.

Have you read the threads about the rear liftgate module on certain model year cx5s? They have a particularly high amount of parasitic drain and a new module fixes that.

As I mentioned in my reply to Silly Wabbit, I too replaced my battery exactly a year ago in October 2020, and things were fine for several months. Then, a few months back now, I started experiencing issues again. I agree that the battery should be able to sustain for a reasonable amount of time, and I would sure think (hope) a new battery should last longer than a year, even with all of the 'fancy' features on these new cars that draw power. Maybe my expectations are unrealistic, though?

As I also mentioned in my reply to edmaz, I don't suppose my lack of driving these days due to my work commute being eliminated since I'm working from home now due to COVID helps matters any. I acknowledge that my quick trips to the market down the street a couple of times a week these days definitely aren't far enough or fast enough for the alternator to charge things up (like you say). The draw I'm seeing when I put my multimeter in series has me convinced this is an issue beyond lack of use, however. Maybe i'm missing the mark though, and my issues really are just from lack of use these days?

I have seen a couple of threads that make mention to the rear liftgate module, but haven't read too thoroughly on those. I wasn't sure if that was for models that have power liftgates, only. Mine is a bare bones Sport model, with manual liftgate. Maybe I should do some more reading on that though...
 
:
Northeast
:
2020 CX-5 Tour
Voltage on the battery yesterday after it had been sitting a couple of days without being driven was around 11.2 volts, which I know is way too low. I don't have a reading right after shutting it down after about a half an hour of running it, unfortunately. ...
You need to find out what the voltage is immediately after shutting down, after a half hour or more of the vehicle running. And you also should check the running voltage, right after starting up and also just before shutting it down after the half hour drive.

When you have those numbers, you can start monitoring the battery - every half hour (or full hour at the most). Doing this simple testing will give you a good deal of information, such as the health of the battery and charging system. You can also have the charging system tested at a parts store, which will provide another view of the charging system health.

Once you have accumulated all of that data, post back with the results. Your vehicle might have a charging system issue, or a parasitic draw, however it's impossible to know what the problem might be, without doing the additional testing. No point in repeating the parasitic draw test yet, until the charging system results are known.
 
:
Pueblo county CO
:
CX-5 Sport 16.5 6M
I understand parasitic draws can be hard to find. Another culprit seems to be the remote FOB left too close to the vehicle overnight. Maybe the constant communication drains the battery.

I think the liftgate issue won't apply to your model.

1.7 amps is pretty substantial. Your new battery, being fully charged, was able to hold up for a while but eventually succumbed.

I think you should recharge your battery to avoid damage, until you find the parasitic draw, or determine how to deal with it.
 

yrwei52

2016 Mazda CX-5 GT AWD w/Tech Pkg
Contributor
:
Plano, Texas, USA
I too replaced my battery exactly a year ago in October 2020, and things were fine for several months. Then, a few months back now, I started experiencing issues again.
This alone I’d take the battery to the seller and have them load-test it and see if the battery is still within specs. I’ve seen some cases that a new battery lasted only within a year. Lack of driving can’t be your problem. Our 2016 CX-5 GT AWD drives sometimes once a month, and has never had any problems to start up. And I don’t use any smart battery charger to maintain the battery voltage.

1.7A parasitic draw is indeed pretty substantial. Even 0.8A is still high after you pulled the fuse #28 for transaxle control system and ignition switch. If that is the constant current draw while your CX-5 is sitting for a while, the battery will be dead within 30 ~ 40 hours as the spec for a normal car battery is 50 AH. Wait for more than 20 minutes and test the current draw like edmaz suggested. Remember the 1.8 A current draw could be from your battery internal itself due to the partial short within the defective battery. What is the brand、model、and type of the battery?
 
This alone I’d take the battery to the seller and have them load-test it and see if the battery is still within specs. I’ve seen some cases that a new battery lasted only within a year. Lack of driving can’t be your problem. Our 2016 CX-5 GT AWD drives sometimes once a month, and has never had any problems to start up. And I don’t use any smart battery charger to maintain the battery voltage.

1.7A parasitic draw is indeed pretty substantial. Even 0.8A is still high after you pulled the fuse #28 for transaxle control system and ignition switch. If that is the constant current draw while your CX-5 is sitting for a while, the battery will be dead within 30 ~ 40 hours as the spec for a normal car battery is 50 AH. Wait for more than 20 minutes and test the current draw like edmaz suggested. Remember the 1.8 A current draw could be from your battery internal itself due to the partial short within the defective battery. What is the brand、model、and type of the battery?

The battery appears to be 'Energy Power' branded, and it looks like the model might be 35C? I don't really know what to look for, but that's what I can find looking at it quickly.

As I mentioned in one of my other replies, I purchased it from a local battery shop that is very reputable. They installed it for me, too. When I purchased it I recall asking the guy who installed it if they had different levels of batteries, as I didn't want to just buy the cheapest one they had. He told me they only had one level battery for the size my car needed, and it was a 'better' one. I think he also said it has a 5-year warranty.

If you think bringing it back to them and having them load-test it would be beneficial, i could certainly do that. Since, like I said, I also think it came with a 5-year warranty, they should replace it for me for free if it's found to be faulty. I just hate to get a new battery put in and then see this happen all over again if there's something else that's causing the drain. I hadn't considered that the battery itself could be causing the draw due to a partial short within.

I still plan on re-testing the current draw as edmaz as suggested. Currently working on getting the other results he requested first, though. Hoping to be able to report back to him on that shortly here.
 
You need to find out what the voltage is immediately after shutting down, after a half hour or more of the vehicle running. And you also should check the running voltage, right after starting up and also just before shutting it down after the half hour drive.

When you have those numbers, you can start monitoring the battery - every half hour (or full hour at the most). Doing this simple testing will give you a good deal of information, such as the health of the battery and charging system. You can also have the charging system tested at a parts store, which will provide another view of the charging system health.

Once you have accumulated all of that data, post back with the results. Your vehicle might have a charging system issue, or a parasitic draw, however it's impossible to know what the problem might be, without doing the additional testing. No point in repeating the parasitic draw test yet, until the charging system results are known.

Ok so here are my results...

- Battery voltage immediately prior to me starting this morning: 11.96 V
- Battery voltage immediately after starting (I had to use a jump pack to start it, of course. Jump pack was removed when I took my reading): 13.92 V
- Battery voltage following about a 40 minute drive, prior to shutting engine off: 13.75 V
- Battery voltage immediately after shutting engine off: 12.34 V
- Battery voltage about 30 minutes after shutting engine off: 12.17 V
- Battery voltage about 60 minutes after shutting engine off: 12.15 V

Not sure exactly what these numbers tell me, but now I'm wondering if my charging system/alternator might be the culprit?

I would certainly appreciate any further suggestions you have for me at this point, given these numbers.
 
:
Northeast
:
2020 CX-5 Tour
....
- Battery voltage immediately after shutting engine off: 12.34 V
- Battery voltage about 30 minutes after shutting engine off: 12.17 V
- Battery voltage about 60 minutes after shutting engine off: 12.15 V

IMO those numbers point to the battery as being the problem with your vehicle. Take it to a parts store and have it load tested, and if that test confirms the battery is bad, I suggest trying to get compensation from where you purchased it.
 

yrwei52

2016 Mazda CX-5 GT AWD w/Tech Pkg
Contributor
:
Plano, Texas, USA
Ok so here are my results...

- Battery voltage immediately prior to me starting this morning: 11.96 V
- Battery voltage immediately after starting (I had to use a jump pack to start it, of course. Jump pack was removed when I took my reading): 13.92 V
- Battery voltage following about a 40 minute drive, prior to shutting engine off: 13.75 V
- Battery voltage immediately after shutting engine off: 12.34 V
- Battery voltage about 30 minutes after shutting engine off: 12.17 V
- Battery voltage about 60 minutes after shutting engine off: 12.15 V

Not sure exactly what these numbers tell me, but now I'm wondering if my charging system/alternator might be the culprit?

I would certainly appreciate any further suggestions you have for me at this point, given these numbers.
Don’t think the charging system is having issues based on your voltage measurements. Either the battery can’t hold the voltage (due to internal short), or there’s a significant current draw somewhere else. A sudden significant current draw is less likely than a defective battery. And replacing a battery is a much easier job than finding a source of unreasonable parasitic draw. Do the most likely and easier thing first and see. You may try load-testing the battery at a random auto parts store, such as AutoZone, and let us know the result.
 
:
Pueblo county CO
:
CX-5 Sport 16.5 6M
12.17v is way low...12.6v is standard at some standard temperature and is the regular benchmark for a charged battery.
 
:
2017 Mazda CX-5 GT, 2016 Mazda6 iGT, 2014 Mazda3 sGT hatchback
> Either the battery can’t hold the voltage (due to internal short), or there’s a significant current draw somewhere else.

One way to find out is, disconnect the battery after engine shut off.
Measure voltage after 0 mins, 20 mins, 40 mins, etc.
The voltage should not drop too much.
If it does, you know there is an internal current leak.
If not, the problem is external... something is draining the battery.
Do you have any device plugged into the 12V socket inside the center console?
Just a guess.
 
:
Pueblo county CO
:
CX-5 Sport 16.5 6M
I noticed my parasitic drain was not as bad after I got a indoor cradle for my XM radio and stopped listening parked in the garage.
 
IMO those numbers point to the battery as being the problem with your vehicle. Take it to a parts store and have it load tested, and if that test confirms the battery is bad, I suggest trying to get compensation from where you purchased it.

Tagging @yrwei52 here, since he recommended having the battery load-tested as well. Here's how that went...

Went back to the place I bought the battery from last October and explained my issue to them. They told me to pull my vehicle in the shop and they'd test the battery for me. Initial test was some overall battery health test, I believe, and it showed it was only like 53% charged or something. So pretty much dead. The guy then had me start my car back up and tested the charging system with the same device. He said the charging system looked to be working fine, so that was good and eliminated the possibility of a faulty alternator, I think. I then inquired about a load-test. He said he would do that one next. So he took the battery out of my car, load-tested it, and it failed. So he said the battery was shot, and was preparing to replace it for me for free under warranty (it has a 24 month full warranty and 60 month pro-rated warranty).

At the time he was about to get a new battery and install it for me, the owner of the of the battery shop wandered over and inquired as to what his worker had decided on the battery. He explained that it failed the load-test, so he was going to replace it under warranty. The owner then inquired: 'what is the discharge on the battery?'. The worker noted that it only showed something like 53% charged on the initial test. The owner then replied that a battery must be fully charged to perform a load-test, or the results will be inaccurate. At this point I really started questioning the intelligence of the worker, and became a bit frustrated. I feel like this is something he definitely should've known working there. I'm thinking he must've been relatively new. That's the only logical explanation for him missing this seemingly critical fact.

Anyhow, since I don't have a charger of my own, I agreed to leave the battery with them, have them charge it up to full, and then re-perform a load-test and see what the results are. In the meantime, they gave me a loaner battery for my vehicle so I could get back home. The owner tells me that if at full charge the battery passes a load-test, the battery is not faulty, and that possibility can be eliminated. He then proceeded to tell me that based on my current driving habits (very little driving these days), he really thinks the vehicle simply isn't being driven enough to keep the battery charged, and that's what's killing it. He said since the onset of the COVID pandemic he's seen literally hundreds of people coming in with the same or similar issues as mine.

Pending the outcome of the load-test on the fully charged battery, he recommended purchasing and installing an on-board battery maintainer (which he sells, of course) for me to use when i'm not going to be driving my vehicle for a few days at a time or what not, to keep my battery charged up and prevent it from draining. The one he recommended is as follows, and his price on it was actually lower than Amazon, surprisingly:


As I've mentioned prior, this particular battery shop is quite reputable locally, so i'd like to think this guy knows what he's talking about and isn't just trying sidestep the true problem and shaft me. I'm having a bit of a difficult time accepting that purchasing and installing this on-board battery maintainer is the only solution to my problem though.

What are your thoughts on this?
 

yrwei52

2016 Mazda CX-5 GT AWD w/Tech Pkg
Contributor
:
Plano, Texas, USA
⋯ He then proceeded to tell me that based on my current driving habits (very little driving these days), he really thinks the vehicle simply isn't being driven enough to keep the battery charged, and that's what's killing it.
As I said before, we don’t drive our CX-5 much, sometimes once a month, and our battery has no issue to start up without a battery maintainer.

Now this’s the best opportunity for you to compare. Check the voltage to loaner battery like before and see if the battery shows the same voltage drop.
 

yrwei52

2016 Mazda CX-5 GT AWD w/Tech Pkg
Contributor
:
Plano, Texas, USA
Pending the outcome of the load-test on the fully charged battery, he recommended purchasing and installing an on-board battery maintainer (which he sells, of course) for me to use when i'm not going to be driving my vehicle for a few days at a time or what not, to keep my battery charged up and prevent it from draining. The one he recommended is as follows, and his price on it was actually lower than Amazon, surprisingly:

Even if you want (or need) a battery maintainer / trickle charger, buy one which can plug in the round cigarette lighter socket so that you can easily use it on any car, not this type which is “dedicated” to one vehicle.
 

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