# 2014 Diesel Battery Issue



## lorilee1929 (May 18, 2016)

So, I am on my third battery and the car is about 85k miles. It looks like this battery is failing and will need replaced soon. The first battery was replaced after less than 3 years of driving, and the dealer went through their and said there was nothing wrong. They replaced the negative battery cord at that time. It seems that replacement time between batteries is getting shorter. Does anyone have experience with this? Were you able to resolve it?


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## boraz (Aug 29, 2013)

ouch.

where in the country are you, as in is it super hot or super cold there? both bad for batteries....

the first battery isnt so bad, assuming high city usage, lots of starts

you gotta have a parasitic drain....some were blaming their onstar, some the bt staying on while parked....


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## snowwy66 (Nov 5, 2017)

I bought my car new and the battery got replaced 3 months later. The car was 15 months old at that time.


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## Rivergoer (Mar 30, 2017)

Maybe related to the OnStar issue, I seem to recall a few people having problems with battery drain after exiting the vehicle while connected on a phone call via Bluetooth.


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## lorilee1929 (May 18, 2016)

snowwy66 said:


> I bought my car new and the battery got replaced 3 months later. The car was 15 months old at that time.


Have you had trouble since?


boraz said:


> ouch.
> 
> where in the country are you, as in is it super hot or super cold there? both bad for batteries....
> 
> ...


Well, I would say I don't live in extreme weather conditions. My travels are almost always longer highway trips, at least an half an hour out and back. I heard both of those excuses from the dealer, Bluetooth and OnStar. But they didn't have a solution. Our Chevy diesel truck doesn't seem to have those troubles and it sits for months at a time. I'm about done with Chevys.


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## snowwy66 (Nov 5, 2017)

lorilee1929 said:


> Have you had trouble since?
> 
> Well, I would say I don't live in extreme weather conditions. My travels are almost always longer highway trips, at least an half an hour out and back. I heard both of those excuses from the dealer, Bluetooth and OnStar. But they didn't have a solution. Our Chevy diesel truck doesn't seem to have those troubles and it sits for months at a time. I'm about done with Chevys.


I don't think bluetooth would. Not sure on OnStar. But the radio, ecm, bcm, tcm, and abs would. 

All my 90's chevy's could sit for weeks. One of them being a manual trans. None of them had OnStar. None of them had agm batteries. 
My 17 cruze had 117 miles when I bought it from sitting on the lot for 13 months. But I wouldn't have any idea if the car ever got jump started. Just that the original battery got replaced 3 months in to ownership.


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## MRO1791 (Sep 2, 2016)

Any additional technical info on the type of replacement battery might help. There is a parasitic draw test that can be done to see if it's a problem with the car electronics. Now if you are putting in the wrong kind of battery, that could be an issue also. The Diesel was specified for AGM, and it needs the protective insulation on the battery under that hood, heat is death for an AGM, especially if being charged at high temperature. The charging system on the Diesel has a feature to vary the rate to save fuel, that ends up also putting an additional strain on the battery, one that is more suited for an AGM battery. I have seen some who have installed a traditional lead acid in the car, I don't recommend that for a number of reasons. My 2015 is with it's second battery. The original was getting a bit weak, but serviceable, I replaced it early to prevent stress on the starting system. 

Sent from my Moto G (5) Plus using Tapatalk


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## snowwy66 (Nov 5, 2017)

I don't see how the varying charge would save fuel on a diesel. Since the only power it needs to run. Is the fuel pump. 

I also don't see how it saves fuel on gas. Since the lower voltage also reduces the igntion spark. 35k volts on battery vs. 50k volts on alternator.


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## S00Tlife (Nov 24, 2019)

snowwy66 said:


> I don't see how the varying charge would save fuel on a diesel. Since the only power it needs to run. Is the fuel pump.
> 
> I also don't see how it saves fuel on gas. Since the lower voltage also reduces the igntion spark. 35k volts on battery vs. 50k volts on alternator.


Your first statement doesn't begin to make sense. Do you think there is one wire going to the fuel pump and that's it? These cars are packed full of electronics.

This second statement doesn't make sense as well. Are you assuming somehow that that variable charge output of amperage is somehow effecting the voltage at the spark plug?

The idea is to vary the ouput of amperage based on the demand at the given time. This decreases parasitic drag on the motor which increases its efficiency. This is why manufacturers are using electric power steering pumps and variable load a/c compressors, among many other things all to increase fuel mileage.


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## MRO1791 (Sep 2, 2016)

snowwy66 said:


> I don't see how the varying charge would save fuel on a diesel. Since the only power it needs to run. Is the fuel pump.
> 
> I also don't see how it saves fuel on gas. Since the lower voltage also reduces the igntion spark. 35k volts on battery vs. 50k volts on alternator.


It's not about voltage, per se. That is what can be seen most easily. The point is amperage into or out of the battery. When the engine is under high load, like going up hill, accelerate, etc. The ECU basically shuts off the alternator, and car is running off battery, which shows as a lower voltage. Then when slowing down, engine braking, light engine loads, it charges back, and voltage goes up, dramatically, over 15v is not uncommon. That kind of cycle would damage a traditional lead acid battery, but it's fine for an AGM. 

Sent from my Moto G (5) Plus using Tapatalk


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## boraz (Aug 29, 2013)

snowwy66 said:


> I don't see how the varying charge would save fuel on a diesel. Since the only power it needs to run. Is the fuel pump.
> 
> I also don't see how it saves fuel on gas. Since the lower voltage also reduces the igntion spark. 35k volts on battery vs. 50k volts on alternator.


just



stop


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## snowwy66 (Nov 5, 2017)

boraz said:


> just
> 
> 
> 
> stop


just




stop


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## snowwy66 (Nov 5, 2017)

MRO1791 said:


> It's not about voltage, per se. That is what can be seen most easily. The point is amperage into or out of the battery. When the engine is under high load, like going up hill, accelerate, etc. The ECU basically shuts off the alternator, and car is running off battery, which shows as a lower voltage. Then when slowing down, engine braking, light engine loads, it charges back, and voltage goes up, dramatically, over 15v is not uncommon. That kind of cycle would damage a traditional lead acid battery, but it's fine for an AGM.
> 
> Sent from my Moto G (5) Plus using Tapatalk



That's not how I've seen it happen. But this is a diesel post so I have no idea on that.

But on my gas. It runs off the battery regardless of uphill or downhill. Acceleration or deceleration. When the battery hits a certain lower voltage, then the alternator kicks in. For topoff purposes.
I've seen alternator run longer when the headlights are on. But everything else doesn't seem to matter on charge time. Accessories such as AC or engine load.

What I've seen so far. Is battery drains, charges, drains, charges. Regardless of conditions.
Don't think I've seen it rise just because I went down hill from work. But I'll check it again.

Now, let's examine the ignition coil. And this is hypothetically speaking as I have no idea the design of coil packs these days. But this is how the system worked in the beginning.
The coil consists of 2 coil windings. Primary and secondary. Primary is 12 volts. When the current is shut off. The primary collapses in to the secondary coil which increases the voltage and sends it down to the spark plugs. Let's say the battery is the source for ignition. 12 volts though the primary windings. 25k volts out the secondary to the plugs. Throw in the alternator. Now you have 14 volts through the primary and say 35k volts out the secondary to the plugs. The primary voltage is increased which increases the secondary voltage.

When the high energy coil pack first came out. Early 90's. Ignition voltage out the secondaries was 50k volts to the plugs. Plug gaps back then were .060. Variable alternators didn't exist. And the mileage interval for changing plugs was 100k miles.
Today, the ignition system in a sense, went back in time. Now the secondary voltage has dropped to ( I think ) 25k volts. And the plug gap has been reduced back down to .028. Do plugs still last 100k miles or are we changing them sooner? I forget what the maint. schedule is.

Take out all the electronics of the computer and what not. And today's igntion system voltage is the same as when the high energy ignition system first came out. Mid 70's. When the distributor was still the standard. With a cap and rotor. The high energy coil sat on the distributor cap.


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## snowwy66 (Nov 5, 2017)

S00Tlife said:


> Your first statement doesn't begin to make sense. Do you think there is one wire going to the fuel pump and that's it? These cars are packed full of electronics.
> 
> This second statement doesn't make sense as well. Are you assuming somehow that that variable charge output of amperage is somehow effecting the voltage at the spark plug?
> 
> The idea is to vary the ouput of amperage based on the demand at the given time. This decreases parasitic drag on the motor which increases its efficiency. This is why manufacturers are using electric power steering pumps and variable load a/c compressors, among many other things all to increase fuel mileage.


It all makes perfect sense.

The fuel pump itself only needs 2 wires. 12v power and a ground wire.

Originally, when they first came out. Most units had 3 or 4 wires. The pump was part of the sender unit assemlby. Power to the pump, power to the float sending unit. And ground wires.

Who said anything about amps? Only volts was mentioned. Just because the 2 go together. Doesn't mean both are part of the conversation.
When voltage input is decreased. So is voltage output.

Technically speaking. You won't get the same ignition voltage off a low battery as you will off the alternator.

For a better understanding. Go back in time to when points and condensor was used. The ballast resistor was used. And the wiring of the igntion system. Both ignition and crank start modes.


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## S00Tlife (Nov 24, 2019)

snowwy66 said:


> It all makes perfect sense.
> 
> The fuel pump itself only needs 2 wires. 12v power and a ground wire.
> 
> ...


Yes the fuel pump needs a power and a ground to operate, this is obvious. You said:



snowwy66 said:


> I don't see how the varying charge would save fuel on a diesel. Since the only power it needs to run. Is the fuel pump.
> 
> I also don't see how it saves fuel on gas. Since the lower voltage also reduces the igntion spark. 35k volts on battery vs. 50k volts on alternator.


When in reality:



> The fuel tank (1) stores the fuel supply. An electric fuel pump module (2) mounted in the tank provides low pressure fuel to the injection pump, The engine control module (ECM) controls the fuel pump operation. Fuel is drawn through a strainer filter at the bottom of the fuel pump. through the rear fuel lines to the fuel filter assembly (3). The fuel filter assembly consists of a fuel filter/water separator, fuel heater, fuel temperature sensor, and a water in fuel sensor. Fuel flows out of the fuel filter assembly through the front fuel lines to the fuel injection pump (5). The belt driven fuel injection pump is mounted on the upper right corner of the engine block. High pressure fuel is supplied through the high pressure fuel line to the fuel injection fuel rail assembly (7). Then through the fuel injector lines to the injectors (10). Fuel pressure is controlled by the ECM, fuel pressure regulator 1 (6) and fuel pressure service valve (8). Excess fuel is delivered to the fuel injection pump and injectors to lubricate and cool the components. The fuel injectors require pressure on the return side for proper operation, this is attained by using a constant pressure regulator (11) located in the fuel injection fuel return hose. Excess fuel then returns to the fuel tank through the return lines.
> *Fuel Tank*
> 
> The fuel tank (1) stores the fuel supply. The fuel tank is held in place by 2 metal straps. The fuel tank is molded from high density polyethylene.
> ...


Not quite the 2 wires you claimed, but close. Oddly enough, I'm coming up with 33 different OE diagrams for the electrical circuits contained within a '14 2.0L Diesel. Wonder what impact they have....

As for the operation of the charging system:



> *Electrical Power Management Overview*
> 
> The electrical power management system is designed to monitor and control the charging system and send diagnostic messages to alert the driver of possible problems with the battery and generator. This electrical power management system primarily utilizes existing on-board computer capability to maximize the effectiveness of the generator, to manage the load, improve battery state-of-charge and life, and minimize the system's impact on fuel economy. The electrical power management system performs 3 functions:
> 
> ...


You said you don't know how lowering the voltage saves gas because it reduces the ignition spark. Are you seeing a decreased afr in those situations or assuming there isn't complete combustion occurring?


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## boraz (Aug 29, 2013)

this dude is comparing the diesel 2.0 which he has zero understanding of to the model t's he has experience with

is he that lonely?


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## boraz (Aug 29, 2013)

snowwy66 said:


> That's not how I've seen it happen. But this is a diesel post so I have no idea on that.
> 
> But on my gas. It runs off the battery regardless of uphill or downhill. Acceleration or deceleration. When the battery hits a certain lower voltage, then the alternator kicks in. For topoff purposes.
> I've seen alternator run longer when the headlights are on. But everything else doesn't seem to matter on charge time. Accessories such as AC or engine load.
> ...


the plugs in the OP's car never need replacing


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## snowwy66 (Nov 5, 2017)

boraz said:


> the plugs in the OP's car never need replacing


Really?

That's kind of some of my point. NO IGNITION SYSTEM.


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## Shroomie (Jan 16, 2017)

Not sure but in my gasser I still have the original battery from 2014... about to be 6 years running on the original battery... I think I might hold the record, 70k miles


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## snowwy66 (Nov 5, 2017)

I had my grand am for 6 years and my cavalier for 7 years. Sold them with the same batteries they came with. No idea when they were actually installed before I bought them.


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## NHRA (Oct 12, 2014)

My 2014 CTD went thru 3 AGM batteries in 6 1/2 years before i traded it in. My 2005 Silverado had the original battery in it for 9 years, 2005 -2014.


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