Vehicle eats new batteries within a month or so?

[sh00ter]

Family member has a Jeep Liberty that started eating batteries and at first they would last a year, now only a few months and then they lose CCA and eventually test bad.

I tracked down a parasitic draw from a phone charger in the lighter socket and thought I had it fixed, but even after that it keeps eating batteries. Could it be overcharging?

 

[cowadle]

check for a bad diode in the alternator

 

[Catt57]

Family member has a Jeep Liberty that started eating batteries and at first they would last a year, now only a few months and then they lose CCA and eventually test bad.

I tracked down a parasitic draw from a phone charger in the lighter socket and thought I had it fixed, but even after that it keeps eating batteries. Could it be overcharging?

check for a bad diode in the alternator

What Cowadle said. Bad batteries can kill alternators and bad alternators can kill batteries. If you are running in circles, I would suggest replacing both at the same time to stop the loop. Also double check the ground connection on the alternator is making good contact.

 

[sh00ter]

check for a bad diode in the alternator

Not sure how to do that other than take the alternator off an to parts house for testing?

What Cowadle said. Bad batteries can kill alternators and bad alternators can kill batteries. If you are running in circles, I would sugget replacing both at the same time to stop the loop.

I did test the alternator output on the vehicle and it is charging within spec. I was thinking about just replacing it but didn't want to throw money at it and have the same issue. I guess if that is next unless I can replace just a diode which I doubt.

 

[Catt57]

Not sure how to do that other than take the alternator off an to parts house for testing?

I did test the alternator output on the vehicle and it is charging within spec. I was thinking about just replacing it but didn't want to throw money at it and have the same issue. I guess if that is next unless I can replace just a diode which I doubt.

Most places like AutoZone or O'Reilly's will test it while you wait.

 

[swampratt]

If you google your issue there are many that have this issue.
Something draining those Jeep Liberty batteries.
One guy found out it was his CD player if he left a CD in the thing and shut the car off it would some how drain his battery dead.

Odd thing but new stuff and electronics never surprises me.
One guy said it was his clock in the vehicle.

I disconnect the negative battery lead and hook a test light between the Negative battery post and the lead I pulled and if it lights the light there is a draw somewhere.

Start pulling fuses until you find it.
If you do not find it disconnect alternator and see what happens with that light.

Fun times chasing issues like that.

I am assuming the battery will just be dead and not crank over after sitting overnight or something like that.

 

[sh00ter]

Most places like AutoZone or O'Reilly's will test it while you wait.

Yeah I have it off and thinking of getting a bench test.

If you google your issue there are many that have this issue.
Something draining those Jeep Liberty batteries.
One guy found out it was his CD player if he left a CD in the thing and shut the car off it would some how drain his battery dead.

Odd thing but new stuff and electronics never surprises me.
One guy said it was his clock in the vehicle.

I disconnect the negative battery lead and hook a test light between the Negative battery post and the lead I pulled and if it lights the light there is a draw somewhere.

Start pulling fuses until you find it.
If you do not find it disconnect alternator and see what happens with that light.

Fun times chasing issues like that.

I am assuming the battery will just be dead and not crank over after sitting overnight or something like that.

I'll try that stuff, thx Swampratt!

 

[sh00ter]

If you google your issue there are many that have this issue.
Something draining those Jeep Liberty batteries.
One guy found out it was his CD player if he left a CD in the thing and shut the car off it would some how drain his battery dead.

Odd thing but new stuff and electronics never surprises me.
One guy said it was his clock in the vehicle.

I disconnect the negative battery lead and hook a test light between the Negative battery post and the lead I pulled and if it lights the light there is a draw somewhere.

Start pulling fuses until you find it.
If you do not find it disconnect alternator and see what happens with that light.

Fun times chasing issues like that.

I am assuming the battery will just be dead and not crank over after sitting overnight or something like that.

Test light comes on that way. Probably confirms a draw? Probably also confirms the alternator is good?

 

[Shinneryfarmer]

Test light comes on that way. Probably confirms a draw? Probably also confirms the alternator is good?

Make sure there is no light under hood and interior lights are turned off in case door is open. These can throw you, if hood light unplug or remove bulb.
You didn't mention year, if later model you have to wait so many minutes for newer systems to power down before making the check with test light between cable and battery. These vehicles keep things energized for a time once key is turned off before shutting down and will lead you down the wrong path.
My 2017 leaves dash and exterior lights powered up with ignition off for several minutes.

 

[sh00ter]

Make sure there is no light under hood and interior lights are turned off in case door is open. These can throw you, if hood light unplug or remove bulb.
You didn't mention year, if later model you have to wait so many minutes for newer systems to power down before making the check with test light between cable and battery. These vehicles keep things energized for a time once key is turned off before shutting down and will lead you down the wrong path.
My 2017 leaves dash and exterior lights powered up with ignition off for several minutes.

I appreciate that info...back a few years ago when I was still trying to fix this issue, I discovered what I thought was a parasitic draw but I bet it was the ECU or something staying energized for a while. I was perplexed because I remember things not adding up. The batteries have been 3yr free replacement so I've just been having to install a new battery about once a year at no cost, but now the issue seems to have gotten worse.