I am really confused now - are there two battery to this van?
You didnāt mention whether your Pacifica is a hybrid, but if it is, it is very possible that it has an auxiliary battery, in addition to the regular battery.
No itās not hybrid
You are so ā¦ā¦ā¦ā¦ take the damn thing to a mechanic.
Mr. Public , there you go being logical again .
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The small battery is the auxiliary battery for auto start/stop. The large battery is the āStorage Batteryā.
The storage/main battery is a group H6 AGM battery.
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I kinda understand how the auto start/stop works when at a stop light etc, but I have not messed around with one (or read up on them) enough to fully understand how the system truly worksā¦
Is there a chance that the vehicle is not starting because the system doesnāt think it needs to until it is in gear and giving it gas?? asking for a friendā¦ lol
I have also always heard (donāt know if true or not) that both batteryās should/need to be replaced at the same time, what say you sir??
Go to Walmart and ask the auto shop to replace your battery. It will be well under $240, and theyāll likely install it for free.
Then see if you still have the problem.
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I have never worked on a Chrysler auto start/stop vehicle, I was going off the parts catalog for battery identification.
The aux. battery should be monitored by the auto starting system, if the aux. battery is failing, the auto start/stop feature should be disabled while driving along with a warning message.
Since jumping the main battery starts the engine, it seems the main battery voltage is low after sitting overnight.
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Huh, would this be a simpler way of disabling the start stop feature I wonder? Just pull the positive cable off?
That ^^. I asked if the OP had a voltmeter and knew how to use it. No matter - $10 and some simple instruction solves that (though it canāt truly load-test). But, no response. Knowing battery voltage when the no-starts happen would tell people a lot - including whether or not it needs a new battery. The only other snag would the possibility of a parasitic draw.
The volt meter will only give a static reading of the battery but it can tell if the alternator is putting ou. Academic though I guess.
Then there is that device hanging off the positive terminal, whatever it is called, that tells the alternator what to do.
I may have missed a reply, but I think we overlooked that the battery/batteries needed to be fully recharged before any testing is done, driving 35 miles I think would not be adequate.
Though I have used both Walmart and Samās batteries with success, with that battery setup I donāt think I would trust it to either store. Would go to a trusted, independent mechanic to install new batteries.
Just a guess, but Batteries Plus guys might be familiar with your system.
In my opinion, yes go with a 750 CCA if it is the same group size.
ā¦ if you can find one!
In my neck of the woods, most of those stores closed their doors over the past 4-5 years.
Hopefully this will be the last update - so this morning ofcourse same scenario, lights come on but engine will not turn. This time I took off the auxiliary battery and took it to autozone to test it - 
dead . Purchase one ($142) came back and plug it back and no hesitation, it started. Will let it sit overnight and try to start it tomorrow. If it comes on, then the auxiliary battery was draining the battery ? Could not be - because if this was the case then the main battery would be low ? Did not jumpstart the van today.
Jump starting if from one vehicle to another is not a good idea anymore . The small jumper packs are not expensive and less likely to cause any electrical problems.
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Iām not familiar w/your make/model/yr or the extra-starter-battery configuration. But if I had those symptoms on my single-battery vehicles Iād be guessing the problem was a faulty starter motor. Before replacing it however, Iād measure the voltage-input right at the starter motor terminals during attempted cranking. If more than 10.5 volts and it doesnāt crank the engine, then Iād replace the starter motor.
My wife took her mother to a doctorās appointment and couldnāt get the car started. The tow truck used a jumper pack to start the car. Even the pros use them. We had one, but it wasnāt in her van. It is now.
It was the auxiliary battery that was causing the issue. All good now
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Thanks for the update, let us know if it changesā¦