Clarify Battery issue

[El-Jefes-Red-Rubi]

2020 Rubi 3.6 AT, 38k miles.

Came out this morning. Jeep unlocked, all seemed normal but then just clicked when I tried to start. Lights, Radio and AC fan all working but no start.

did a normal connection Jumpstart off my other car and it fired off instantly with no issues. I moved my Jeep and drove the other car to town.

question: if my aux battery is bad would it jump start immediately? All the information seems to say contradictory. Is it my primary battery that died?

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[GrayWolf.Overland]

I suspect that is the primary. When you "jump started" - it essentially put some charge into main but the cranking actually happened through the juice in AUX and not from the jumper cable?

there are better experts here who can confirm the above.

 

[Dyolfknip74]

2020 Rubi 3.6 AT, 38k miles.

Came out this morning. Jeep unlocked, all seemed normal but then just clicked when I tried to start. Lights, Radio and AC fan all working but no start.

did a normal connection Jumpstart off my other car and it fired off instantly with no issues. I moved my Jeep and drove the other car to town.

question: if my aux battery is bad would it jump start immediately? All the information seems to say contradictory. Is it my primary battery that died?

Isolate the batteries and check voltage. Trying to guess here is about as easy as trying to give you a haircut over the phone.

 

[Reinen]

This is a situation where it's best to not go cheap and replace both Main and Aux at the same time.

The two batteries are linked so even if one is still technically "good", the bad battery is currently overstressing the still good one. If you only replace the bad battery, the other battery will never have a lifespan as long as the new battery. You're just setting yourself up to eventually have the battery you didn't replace to go bad and overstress the battery you did replace, reducing its lifespan.

You'll end up buying fewer batteries over time if you always replace both at the same time, regardless of whether one still tests "good". If one is bad, the other is compromised. Replace both.

 

[Jebiruph]

2020 Rubi 3.6 AT, 38k miles.

Came out this morning. Jeep unlocked, all seemed normal but then just clicked when I tried to start. Lights, Radio and AC fan all working but no start.

did a normal connection Jumpstart off my other car and it fired off instantly with no issues. I moved my Jeep and drove the other car to town.

question: if my aux battery is bad would it jump start immediately? All the information seems to say contradictory. Is it my primary battery that died?

Both of your batteries were low on charge, because they are wired in parallel they discharge and charge together. You caught them before they discharged too far, so it was easy to jumpstart.

At this point you don't know if either battery is bad, they may have been gradually loosing their charge over time from a lack of driving. Charge them up and if you are concerned about their condition get them load tested.

 

[El-Jefes-Red-Rubi]

I drive this Jeep daily. Never just sitting around for the battery to drain. 26months old, 38k miles. Why would the batteries die?

also, my gauge says 13.7-13.8 battery voltage. I could swear it use to be 14+. Thoughts?

 

[jessedacri]

I drive this Jeep daily. Never just sitting around for the battery to drain. 26months old, 38k miles. Why would the batteries die?

Do you have anything non-factory wired up like a winch or anything, and do you have a Tazer or other programmer? I doubt the lights in your signature would cause anything if they're wired up to the aux switches and/or fully off on another switch.

 

[Reinen]

I drive this Jeep daily. Never just sitting around for the battery to drain. 26months old, 38k miles. Why would the batteries die?

also, my gauge says 13.7-13.8 battery voltage. I could swear it use to be 14+. Thoughts?

The problem is that every moment it is not being driven something is slowly draining the batteries. The JL (and all other modern vehicles, not just Jeep) are never completely off. This is really rough on AGM batteries and it's why batteries no longer last 5-7 years like they used to. 2-3 years is the average in a modern vehicle.

 

[El-Jefes-Red-Rubi]

Do you have anything non-factory wired up like a winch or anything, and do you have a Tazer or other programmer? I doubt the lights in your signature would cause anything if they're wired up to the aux switches and/or fully off on another switch.

yes I have a Tazer installed. A winch but it’s off. Lights are all through the aux switches.

 

[Rhinebeck01]

yes I have a Tazer installed. A winch but it’s off. Lights are all through the aux switches.

@El-Jefes-Red-Rubi

Do you have the feature "In Motion Nav", Tazer JL feature enabled? If so, that is one thing that could possibly have caused your depleted battery(2) issue.... but undoubtedly it was other reasons.

 

[jessedacri]

yes I have a Tazer installed. A winch but it’s off. Lights are all through the aux switches.

The Tazer can definitely drain your battery if you have stuff like the permanently disable auto start/stop feature turned on, but mine hasn’t killed i unless I leave it for over a week.

 

[Rhinebeck01]

The Tazer can definitely drain your battery if you have stuff like the permanently disable auto start/stop feature turned on, but mine hasn’t killed i unless I leave it for over a week.

@jessedacri

I disagree with what you are saying in regard to the Tazer JL and the "start/stop feature". That feature can be enabled full-time and there is no negative impact on the battery(s).

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