Battery went completely Dead. Jump-started, now engine is shaky and weak?

No need to remove the battery if it can be recharged successfully in place.

I do have a 10amp charger I've used on occasion but smaller 1-2 amp chargers do a better job of charging sometimes, even though they need more time.
Charge it til it's charging over 14v (check w DMM )
The resting voltage at room temperature should be 12.6 but right after a thorough charge might be over 13.

I use a battery maintainer or tender on a regular basis because I don't drive a lot.
 
Gotcha. I'm considering just going into mazda and have them doing this if I have to pay $50+ to buy this equipment.

Can you explain why charging the battery more MIGHT fix the issue if the battery is already charged and running? What will a few more amps do?

Also - is there any way to reset the computer system or does Mazda have to do that?
 
I called Mazda. They seemed to offer little to no information. You guys are much more helpful.

They didn't really say there is something to reset the computer system though.

He did tell me as well to give it a charge and go from there.
 
If your battery measures at least 12.6v [edit: between 12.3 and 12.6V is fine] after the car has been shutoff for 15 min (no headlights or accessories running), then whoever load tested is probably right. If the battery terminal voltage is at least 13.6v idling, then the charging system is fine.

Whether you connected the black jumper cable to engine or body metal, or directly to the negative battery post matters nothing to the car. You connect to engine or body metal simply so the sparks are farther away from any hydrogen gas hanging around the battery when it is in a discharged state. Few want a dead battery and shrapnel.

My guess is that the PCM lost some long term memory when going flat or being jumped, and it's having to relearn everything from fuel trims to idle speed. Doing 3 or 4 WOT runs to 60mph should recalibrate most everything.
 
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@AVC Thanks for the input! I'm going to buy a cheap voltage tester from Amazon and check. Do you know if the USB ones work good enough?

Can you explain what WOT runs are? I've driven the car a few times going over 45/50 mph.

I am a bit nervous to continue to drive it incase it will screw something up.
 
USB meter?

I prefer something that will measure directly across the battery. A Harbor Freight or Walmart $6 meter is plenty sufficient for this and other general troubleshooting.

Wide Open Throttle runs (after the engine is fully wamed up). Most PCM's relearn long term fuel trim blocks, MAF, MAP blocks, transmission and other parameters then. If it starts, runs and shifts without big drama now, you won't hurt anything by WOT runs.
 
Sorry I meant cigarette lighter.

I've driven the car for about 30 miles since this has happened and it's still having issues. Don't you think that would be enough to fix the issue?

Also may be worth nothing, i did replace the car engine filter right before this happened. Although I can't imagine that has anything to do with the sound..
 
If you had any issues removing or reinstalling the air filter or maybe you inadvertently disturbed a sensor or wire... who knows? Do you have a code reader for the obdii port under the steering wheel?

I just bought a new Black and Decker Battery maintainer for a little over 20 bucks.

A slow, low amp charge does a better job charging because it evens out the chemical imbalances batteries sometimes develope.

Removing the cable should help clear out bogus computer data that might have messed up your ECM. The computer is designed to re-learn after a complete loss of power.
 
How can connecting a jumper directly to the battery terminals damage the battery control? Jumping is like temporarily putting in a new battery, no?
First, I used the wrong term. I called it "electronic battery control module", what I meant was "electronic battery sensor". Modern cars have a battery sensor connected to the negative terminal (often not right at the terminal, but further down where you can't see it).

The owners manual specifically says connect negative from donor car to a ground point on your car if jump starting (not negative to negative). One reason is to avoid sparks, but the other reason is that connecting negative to negative when jump starting can easily mess up how the electronic battery sensor reads the inputs and cause problems like those the OP describes. If this is the problem, it's an easy fix. But best to follow the directions in the owners manual to avoid problems.

Here's an article explaining what this "fragile" sensor does in modern cars.
Doesn't talk a lot about jump starting, but one sentence from the article in particular:
"It is also important where to connect the wire clamps when boosting or charging the battery with a battery sensor."
 
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@Mazdiod2 Pretty positive I didn't mess anything up because I simply opened the cover and put it in.

Unfortunately, I do not have a code reader. I am putting my money on that because the negative was place on negative, it caused some sort of malfunction, because I did see a spark.

I am going to charge tomorrow with one I bought on Amazon. So we will see if it helps!

Quick question - do I need to unhook the negative or anything? Or can I just charge the battery as is?

And what do you mean by "removing the cable"?
 
I think you want more than a 2 Amp charger. I have a 2/5/10 charger from Walmart's bought 10 years ago.
 
High amperage contacts will alway spark, that is not an issue.
Did you put back the air filter cover correctly? Not getting extra air by any chance?
 
Yeah, this battery/charger rabbit hole is a waste of time, guys. OP, did you measure the non-running and running voltage at the battery?

I'm with tibi, in that something else has changed other than this jump start event.
 
Whether you connected the black jumper cable to engine or body metal, or directly to the negative battery post matters nothing to the car. You connect to engine or body metal simply so the sparks are farther away from any hydrogen gas hanging around the battery when it is in a discharged state. Few want a dead battery and shrapnel.
Yes, the main purpose of connecting the negative cable clamp to the engine or body metal of the dead battery vehicle is for safety reason. Another minor benefit is to eliminate any possible bad connections on negative battery post (i.e. corrosion at post area) or any other abnormal resistance on negative wiring to the starter of the dead vehicle during jump-start which requires substantial electrical current.

In fact, car manufactures have been recommending clamping the negative side of jump-cable to engine and body bare metal long before the sophisticated battery management system with battery current sensor exists. The owner’s manual of my first vehicle, a 1974 Chevrolet Impala, has stated connecting negative clamp to the engine hook. As for our Mazda CX-5 without i-stop (Stop-Start feature) and AGM battery in the US, and our owner’s manual doesn’t provide any warnings about having possible damage to battery management system or battery current sensor, I highly doubt clamping to the negative post directly during jump-start would damage the battery current sensor if it does exist in our US CX-5. And I doubt there’s a need to reset battery manage system for US CX-5 if it indeed exists.
 
@AVC I put it exactly as the one was in before that.

This is what i put in: https://www.amazon.com/dp/ (commissions earned)

At autozone the measured the battery when the car was turned off. It measured at 12v.I Unfortunately i don't have anything to measure myself.

I purchased a 2A charger that is arriving today. Hopefully it will be enough if I leave it on for several hours.

Does anyone have a tutorial they can share how to remove one of the battery terminals before charging?

I have never done this before and want to make sure I do it correctly.

And I know I have no experience with this, but the issue has to have stemmed from the jump. It worked perfectly fine beforehand.
 
And if the battery sensor were damaged, it would show up....wait for it... in the off/running battery terminal voltages, or of course in a dead car (no lights, no start, no ring a ding a ding).
 
Yeah, this battery/charger rabbit hole is a waste of time, guys. OP, did you measure the non-running and running voltage at the battery?

I'm with tibi, in that something else has changed other than this jump start event.
Yes, I agree. And I‘ve said so in my early post in this thread.
 
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