Battery Dead .5~1.0V voltage drop normal?

[StylingSequ]

Your multimeter has a fuse, to prevent being destroyed from situations of too much current, just need to replace the fuse with one of the correct rating. It may have come with a spare fuse.

I suggest taking your car to a professional, you are in over your head troubleshooting this yourself.

The crazy thing is that the car is covered under warranty, so I have no idea why I have to do all this.

I took it the dealer who insisted that the problem was caused by the body shop's front work. The body shop thinks it's the battery although it doesn't look like the case now…

 

[Conrad 16.5]

Maybe I misread my multimeter and it was 5 milliamps? But then wouldn't 5 milliamps be a bit too low?

I don't get it because wouldn't 5 amps drain the battery overnight? (I was able to start the battery this morning.)

I burned my multimeter so there is no way to recheck it until I get to buy a new one. I'll let you know.

I asked you way back in post #6 if you had a multimeter, it seems that you do, or did rather. As said above, the meter should have a replaceable fuse.

How exactly are you measuring the current draw of the battery? As you found out, don't try to measure by placing the meter probes across the battery terminals.

 

[RedBaron]

I actually just did a parasitic draw test. The multimeter actually showed 5.00 amps (not milliamps) are being drawn)

The circuits in the car will still run for a time after turning off the ignition. Leave your meter IN PLACE and come back after ~20mins or so, and report back the reading then.

 

[RL911]

What does the battery read with the car running? Should be 13.9-14.4.

What does it read with the car off?

 

[StylingSequ]

What does the battery read with the car running? Should be 13.9-14.4.

What does it read with the car off?

The voltage reader still works on the multimeter. I get 14.3 while the engine is running and 12.14 while the engine is off. I guess the battery needs to get charged. I just got the Victron battery charger in the mail last night so I'm going to fully charge it.

 

[StylingSequ]

As you found out, don't try to measure by placing the meter probes across the battery terminals.

Yep, I learned that the hard way. ¯\_(ツ)_/¯

You're right. I shouldn't have made a new thread. I thought it would make it more convenient for new readers but it makes it harder for current ones.

 

[StylingSequ]

Man, that’s super frustrating! Sounds like you’re getting the runaround from both sides. Honestly, if your battery is dropping to 11.1V just from basic electrical load, that ain’t normal. Even if it’s testing 'fine' at the dealer, real-world performance says otherwise.

If you’ve got a multimeter, check the resting voltage after sitting for a while—should be around 12.6V+. Also, you might wanna do a parasitic draw test to see if something’s draining it when the car is off.

If the shop is right and the battery’s just weak, you might have to bite the bullet and swap it yourself or get Mazda corporate involved since the dealer won’t budge. Either way, I’d push for a proper diagnosis instead of them playing the blame game. Hope you get it sorted!

Yep, the shop owner was really pissed off at the dealership. I think he had every right to be. The dealerships around here are really shady. They have the worst reputation in NJ. Yet they still make tons of $$. They make so much money that they spread so fast with multiple dealerships over multiple brands.

It does seem like I have to pay for the battery out of pocket if that's the cause. That's what the shop owner said too. It's just not worth the aggravation to claim the warranty via the dealer. Pisses me off though.

Mazda corporate is just as bad. I had and still have an issue with my remote key fob. From the start, my doors didn't lock about a third of the time. (I read that an unlocked door leads to a parasitic draw.) I know that it's not in my head because I drove my mother-in-law's CX-5 for a week, and the doors locked perfectly. Mazda corporate outright said that I have to live with the doors not locking all the time.

All of this made me having doubts about Mazda. I actually got about $1k in accessories for my CX-5 (trailer hitch, roof rails). The dealership took them off and gave me the car without them during purchase. I'm guessing they are selling them separately to make additional $$. They also kept the excess registration fees that they were supposed to give back. They claimed they sent it in the mail but of course, I never got it. Their shadiness is so out there that I can only laugh.

 

[RL911]

The voltage reader still works on the multimeter. I get 14.3 while the engine is running and 12.14 while the engine is off. I guess the battery needs to get charged. I just got the Victron battery charger in the mail last night so I'm going to fully charge it.

That battery is bad. If your alternator shows 14.3, it’s good, but battery can’t hold a charge. If I were you, I’d stop messing around, go to Walmart and get a new battery. Anything below 12.3 and you can easily have starting issues. Charging the battery won’t help you. Your alternator is already charging it and you have issues.

I had Honda tell me my battery tested good on my pilot. Took it home, wouldn’t start again. Took it back, they replaced the battery and it was good for three years.

 

[StylingSequ]

That battery is bad. If your alternator shows 14.3, it’s good, but battery can’t hold a charge. If I were you, I’d stop messing around, go to Walmart and get a new battery. Anything below 12.3 and you can easily have starting issues. Charging the battery won’t help you. Your alternator is already charging it and you have issues.

I had Honda tell me my battery tested good on my pilot. Took it home, wouldn’t start again. Took it back, they replaced the battery and it was good for three years.

You're saying what the body shop owner and a different mechanic said. They both believe it's a bad battery. Thanks, I appreciate the advice. Reassures me on what to do.

 

[StylingSequ]

The circuits in the car will still run for a time after turning off the ignition. Leave your meter IN PLACE and come back after ~20mins or so, and report back the reading then.

I finally got a new multimeter and measured the current. There definitely is a parasitic draw. This time I measured it at 4.4A. This time I left the car turned off for 30 minutes. I read that it can take up to 2 hours for everything to turn off though. I guess I'll take another reading in the morning.

It looks as if it's not the battery. Or it is also the battery since the constant parasitic draw has been draining the battery and thus damaging it.

I'll try to measure the millivoltage across fuses to see where the draw is coming from. I'll probably do it tomorrow since it's already too dark.

Btw, is it normal that there is a spark when I touch the multimeter with the battery's negative terminal?
To test the current, I disconnected the battery's negative terminal. Then I connected the multimeter in series with the battery. I connected the black probe of the multimeter to the car's disconnected cable and then I connected the red probe to the battery's negative terminal. When I do this, there is occasionally a spark. Is this normal?

 

[ADS-B]

What are you checking, voltage? Current? You put the black probe to the negative(ground) terminal first! Then you touch the positive terminal of the battery! If you're checking voltage, make sure the multimeter is set for DC voltage, not AC. Always remember, you ground first before you touch the load, the positive. When you remove the multimeter leads, you do it in reverse. You disconnect the red lead from the positive terminal first and then remove the ground.

 

[StylingSequ]

What are you checking, voltage? Current? You put the black probe to the negative(ground) terminal first! Then you touch the positive terminal of the battery! If you're checking voltage, make sure the multimeter is set for DC voltage, not AC. Always remember, you ground first before you touch the load, the positive. When you remove the multimeter leads, you do it in reverse. You disconnect the red lead from the positive terminal first and then remove the ground.

I'm checking the current. I didn't realize that the order mattered since I'm connecting the multimeter in series. So I should connect the red probe to the disconnected cable and then the black probe to the battery's negative terminal.

 

[Conrad 16.5]

The order of connections doesn't matter. What are you talking about ADS?

"You put the black probe to the negative(ground) terminal first! Then you touch the positive terminal of the battery! "

This is for checking the battery voltage and the order make zero difference.

When checking for current draw, the order makes no difference either. BUT, as I said in the other thread, care should be taken when doing things that can produce a spark near the battery.

When checking current, since this is a digital meter, it doesn't matter which probe goes where since the meter will display the negative sign in front of the value measured.

 

[ADS-B]

When you check for current or voltage, for your safety and to prevent any damage to equipment, you ground first. Order does matter.

 

[Conrad 16.5]

When you check for current or voltage, for your safety and to prevent any damage to equipment, you ground first. Order does matter.

While troubleshooting a circuit, voltage readings are not always taken with reference to ground, what then?

The impedance of today's modern multimeters is in excess of 10M ohms. Which means that no sparks will be generated by connecting the probes (when checking voltage) and it most certainly does not matter what order you connect the probes.

When checking current, sparks can most certainly be generated, and care must be taken. But the order of connecting the probes does not matter!

I worked in the electronics field for over 30 years, repair, design, modification, and maintenance. Not once did I ever worry about the order of connections with either a multimeter or an oscilloscope.

Have I been doing it wrong all these years? If so, I never suffered any negative consequences, either at the bench or in the field.

 

[Conrad 16.5]

What are you checking, voltage? Current? You put the black probe to the negative(ground) terminal first! Then you touch the positive terminal of the battery! If you're checking voltage, make sure the multimeter is set for DC voltage, not AC. Always remember, you ground first before you touch the load, the positive. When you remove the multimeter leads, you do it in reverse. You disconnect the red lead from the positive terminal first and then remove the ground.

In your example, if one was to test the current draw. The negative cable would be removed from the battery and the probe attached to the negative cable first, right? Then the other probe would be connected to the battery's negative terminal, right? This would most likely generate a spark at the negative terminal RIGHT ON TOP OF THE BATTERY and if hydrogen gas was present, BOOM!

Sparks need to be kept as far away from the battery as possible!

 

[hsdejong]

Sparks need to be kept as far away from the battery as possible!

While the risk is relatively low with a properly maintained battery, it's always good advice!
Many batteries these days are maintenance free and I doubt that under normal charging conditions they will vent oxygen and hydrogen gasses.

And yes, when connecting the battery terminal there could be a small spark, because of the extra temporary (peak) current needed to "charge" all electronic devices (electrolytic capacitors).

And no, it does not matter in which order you connect the meter cables.

P.S.
When replacing an old battery, we first disconnect the negative terminal. When connecting a new battery, we first connect the positive terminal. This prevents you from creating a short circuit with the wrench by accidentally touching a metal car part when loosening or tightening the battery terminals.

 

[RL911]

I finally got a new multimeter and measured the current. There definitely is a parasitic draw. This time I measured it at 4.4A. This time I left the car turned off for 30 minutes. I read that it can take up to 2 hours for everything to turn off though. I guess I'll take another reading in the morning.

It looks as if it's not the battery. Or it is also the battery since the constant parasitic draw has been draining the battery and thus damaging it.

I'll try to measure the millivoltage across fuses to see where the draw is coming from. I'll probably do it tomorrow since it's already too dark.

Btw, is it normal that there is a spark when I touch the multimeter with the battery's negative terminal?
To test the current, I disconnected the battery's negative terminal. Then I connected the multimeter in series with the battery. I connected the black probe of the multimeter to the car's disconnected cable and then I connected the red probe to the battery's negative terminal. When I do this, there is occasionally a spark. Is this normal?

4.4a is a huge draw, that can’t be right. Do you mean 44ma?

Have you tried pulling fuses yet?

 

[StylingSequ]

4.4a is a huge draw, that can’t be right. Do you mean 44ma?

Have you tried pulling fuses yet?

Nope, it was 4.4A. This time I made sure the range was correct. The range setting was 10A.

I read that to get an accurate reading, you should make sure the battery is fully charged, so I fully charged the car battery with the new Victron battery charger. After the battery was fully charged, the voltage was over 15V. I read that this is high but acceptable. I figured that this was just due to using the Victron for 4 hours.

I then connected the multimeter in series with the negative battery terminal. (I made sure that I didn't connect the positive and negative terminals with the multimeter. And I suspect I didn't do that the first time.) I again set the range at 10 A. There wasn't any reading. I checked the fuse and it looks like it's blown. Ugh…

Is it normal that the multimeter fuse gets blown by checking the battery's current?

 

[StylingSequ]

While troubleshooting a circuit, voltage readings are not always taken with reference to ground, what then?

The impedance of today's modern multimeters is in excess of 10M ohms. Which means that no sparks will be generated by connecting the probes (when checking voltage) and it most certainly does not matter what order you connect the probes.

When checking current, sparks can most certainly be generated, and care must be taken. But the order of connecting the probes does not matter!

I worked in the electronics field for over 30 years, repair, design, modification, and maintenance. Not once did I ever worry about the order of connections with either a multimeter or an oscilloscope.

Have I been doing it wrong all these years? If so, I never suffered any negative consequences, either at the bench or in the field.

Conrad, the multimeter's fuse got blown again when I was checking the amperage. Initially, it came out at 4.4A but when I checked it again after charging the car battery, it looks like it got blown again.

The amp setting is at 10A. Is that just too low for a car battery?

Is this all normal?