Battery keeps dying after only a few days, please help!

[gttafoya]

GPS Tracker that was installed by the dealer?

My Focus wouldn't hold a charge for more than a few days (same as OP). I went through 4 batteries in ~6 months.
Troubleshooting the problem found a GPS tracker spliced in next to the fuse box.
Once removed, The battery can now hold a charge for at least 2 weeks - that's the longest it's been between drives so far.

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[Motorpsychology]

I found something interesting in the Owner's Manual:

 

[AzScorpion]

I found something interesting in the Owner's Manual:

Good thing I have push button start.

 

[dtech]

Ok, took me a while to understand what our Rangers are doing and Fords approach to the charging system. Because we have an AGM type battery things are different than the old days, much different really. The way Ford has set this up they only charge the battery to 70% of its total capacity. This is supposedly for longevity of the battery. There is a setting if you Have Forscan to change it. Some have also unplugged the connector in front of the battery box that will disable ASS and also disable AGM system entirely. That charges your battery to 100%. When ever your battery reserve is low your ASS or auto start will disable itself by default.

It does sound like you could have a bad cell and some testing will reveal this

Sounds like this might allow for replacing the AGM battery with a wet cell lead acid

 

[Motorpsychology]

Good thing I have push button start.

For longer battery life, maybe disconnect the button each time you leave the truck.

 

[alazar14]

So turns out it was not just the battery. Yes the battery did fail a load test and so they did replace it under warranty, but they also found some minor rodent damage in some of the wiring. I park outside in a car port, so I'm really frustrated that this happened. I could understand if I had a dirty home, messy garage, or something like that, but nope, outdoors. $435 replace a few cables and splice together wires. Feel like I was overcharged but at this point, with a road trip coming next week I have to have the truck in tip top shape.

 

[dapakattack]

Juan, glad you got it taken care of. Have a safe trip! Did you end up going to another dealer? There are several posts about our wiring and how rodents like to chew them up.

 

[alazar14]

Juan, glad you got it taken care of. Have a safe trip! Did you end up going to another dealer? There are several posts about our wiring and how rodents like to chew them up.

I did end up going to a different dealer, yes. These guys did a full diagnostic, kept the truck for a day and said they checked for additional issues. Once they found rodent damage, they said they had to check a lot of things to make sure it wasn't so extensive. I think that's prob why they charged me so much.

 

[Motorpsychology]

Juan, glad you got it taken care of. Have a safe trip! Did you end up going to another dealer? There are several posts about our wiring and how rodents like to chew them up.

It's not just rats or mice after the wiring. Squirrels moles, voles can also attack if hungry enough. modern wiring has soy-based plastic insulation, and they are after the protein.

 

[dtech]

Rodent damage story - in the 70s lived on the ground floor of a building - dumpster outside of my wall, I could occasionally hear noises in the wall, had seen a rat hanging out at the dumpster. One night suitably intoxicated left a bar with a friend and ordered burritos at a drive thru, went to my place and drunken friend drips burrito contents all over a sweater he's wearing, he proceeds to pass out on my couch. In the middle of the night I awake to hear yelling, my friend is standing there with a hole eaten through his sweater, I never laughed so hard in my life and you can bet he never stayed at my place again.

 

[Dgc333]

If you have issues with rodents they sell devices you mount under the hood that emits ultrasonic sound and strobes an LED to keep the critters away. They sense change in battery voltage to automatically turn on when you shut the vehicle off and shut off when you start the vehicle. They also shut off if the battery voltage gets to low.

A couple of years ago the little bastards got into my Barracuda and made a nest above the head liner and ate a hole in it. I got one of these devices and mounted it inside the car and have not seen any signs of mice since.

 

[importfighter01]

Sounds like this might allow for replacing the AGM battery with a wet cell lead acid

^This I replaced the smaller stock XL AGM battery I had stock with a larger Lariat size battery but made it a wet cell from Walmart too. Left the ASS unplugged and now whole system functions like my 99 Ranger did. So good news is you can still covert the truck to be “old school” in battery charging / mgnt.

 

[towpro]

Ok, took me a while to understand what our Rangers are doing and Fords approach to the charging system. Because we have an AGM type battery things are different than the old days, much different really. The way Ford has set this up they only charge the battery to 70% of its total capacity. This is supposedly for longevity of the battery. There is a setting if you Have Forscan to change it. Some have also unplugged the connector in front of the battery box that will disable ASS and also disable AGM system entirely. That charges your battery to 100%. When ever your battery reserve is low your ASS or auto start will disable itself by default.

It does sound like you could have a bad cell and some testing will reveal this

THIS is how you fix it.
I turned my charge capacity up to 95% or something like that (can't recall). Mine sits a week or 2 between short trips. Now I did nothing to my Wifes 2020 escape hybrid and the battery was total dead after just over a year.

 

[JonB]

I'm glad the OP found a dealer who found the problem and fixed it. There were a lot of other suggestions here, some of which, IMHO, were ill advised.

The truck has a battery management system (BMS)which is pretty smart. Messing with it may produce some short-term results but, in the long run, will do more damage than good. Because of this BMS one should not use Forscan to reprogram the battery charging. Increasing an AGM battery's charge to 100% will shorten its life. Trying to boost the charge voltage will do the same.

Bottom line, there are three lines of attack when diagnosing battery problems:
1. Is it getting a charge - check alternator output.
2. Is it holding a charge - load test the battery
3. Is the charge being drained - look for parasitic drains on the battery when all systems are off.

 

[Old Red Replacement]

Better luck with Motocraft BA6-48H6-760
Warranty replacement or use other brand like Odyssey?

Starts but losing voltage sitting one week 11.7, recharged to 12.99 next day 12.64, don’t care about cost want issue fixed, alternator charging + 15 Volts, no start / stop.

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