Auxiliary 12v Battery

[Kodiak]

In some of the battery threads there is a post with a link to a somewhat larger O'Rielly's aux 12v battery. I would like to use this and replace the OEM Ford battery with this larger one. However there is some "device" (see pictures) that is preventing me from adding the length needed to add this longer battery. I tried to pull it out but it is not budging and I do not know if it has wires going down through it. I hate to just "yank" it out and may need to disassemble the whole thing to see what is happening.

I thought I would ask here first to see if anyone else was able to do this and what they did to "unattach" this device. The new larger battery just bumps this out so I do need to move it a little and there is plenty of room since the PB only has one aux battery.

Any incite to this is appreciated.

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[Kanuck]

To me, that looks like a current sensor, similar idea to what is on the main battery. Ford would be prudent to monitor the load/draw on that battery.

 

[Kodiak]

That is the BMS

Were you one of the people who changed that aux battery to the O'Rielly one? If you were how did you get it moved.

 

[Kanuck]

That is the BMS

Is there not one connected to neg post on the main 12 volt battery under the hood? That would also be BMS.

 

[HammaMan]

That's a current transformer for monitoring amperage. Should be able to pull it up w/ out issue. Remove the tape from the conductor if you need to change its position. I was able to retain it w/ the LFP install, it's just hidden

 

[FaaWrenchBndr]

Were you one of the people who changed that aux battery to the O'Rielly one? If you were how did you get it moved.

Major brain fart…..simply wasn’t paying attention. That’s a current sensor for the auxiliary battery.

 

[FaaWrenchBndr]

Is there not one connected to neg post on the main 12 volt battery under the hood? That would also be BMS.

im a dumbass that doesn’t pay attention……it’s a current sensor for the battery

 

[safety_3rd]

With the battery I got (https://www.oreillyauto.com/detail/...op-post-battery-group-size-btx14ah/ssbn/etx15) I was able to leave it in. However the strap doesn’t fit around the battery any more and I had to leave the top part of the cover unhooked in the back I also added the gold washer things that came with the battery as a spacer. The positive ford terminal hook up is large and in order to thread the bolt in, the terminal got caught in a little ledge on the battery. I tried to add this in the pictures. You can also reset your battery management system (bad) by getting in your truck, pressing the start button without your foot on the brake (or turning your key to the aux without starting), flashing your brights 5 times, then pump your brakes 3 times. The battery icon on your dash should flash three times. You don’t have to do this though, it resets after 8 hours of being parked any ways.

 

[dmsween]

@HammaMan,

Is that this battery?
https://a.co/d/1Q6hi9Z

That's a current transformer for monitoring amperage. Should be able to pull it up w/ out issue. Remove the tape from the conductor if you need to change its position. I was able to retain it w/ the LFP install, it's just hidden

 

[Spiffy]

What does this battery do?
When we reset the bms by the headlights/brake peddle how do we know of it resets both the main and this auxiliary battery?
The dealership replaced the main battery the other day and I'm still having trouble with the interior lights coming on when I open the door. They come on when I start the truck. Main battery is 14.3 volts.

 

[safety_3rd]

What does this battery do?
When we reset the bms by the headlights/brake peddle how do we know of it resets both the main and this auxiliary battery?
The dealership replaced the main battery the other day and I'm still having trouble with the interior lights coming on when I open the door. They come on when I start the truck. Main battery is 14.3 volts.

Yea thats an issue with the underseat battery. What year and model do you have. Replace the aux battery and do a bms reset and your light will come back on. Also make sure you didn’t accidentally turn off the light on your overhead consul. It should be orange to match the other buttons not blue (off).

 

[Kodiak]

With the battery I got (https://www.oreillyauto.com/detail/...op-post-battery-group-size-btx14ah/ssbn/etx15) I was able to leave it in. However the strap doesn’t fit around the battery any more and I had to leave the top part of the cover unhooked in the back I also added the gold washer things that came with the battery as a spacer. The positive ford terminal hook up is large and in order to thread the bolt in, the terminal got caught in a little ledge on the battery. I tried to add this in the pictures. You can also reset your battery management system (bad) by getting in your truck, pressing the start button without your foot on the brake (or turning your key to the aux without starting), flashing your brights 5 times, then pump your brakes 3 times. The battery icon on your dash should flash three times. You don’t have to do this though, it resets after 8 hours of being parked any ways.

Great writeup with pics and thanks so much for posting this. I think I will look into a longer bolt for the hold down strap to get that to work.

That was good to hear that you can squeeze it in without having to pull out and move the device that I was showing. It looked like I may have to trim some tabs in the battery tray but that is easy.

I plan to swap this out and then go to Costco for a new main battery and I will reset the BMS at that time. I'm just glad to hear that this bigger battery can work. Thanks again and thanks for the great pics!

 

[safety_3rd]

Sure thing. I went with a traditional lead acid AGM battery over a lithium battery because 1) I think a lithium battery requires a different type of charger and I was worried that the stock alternator or whatever software that ford uses might not charge properly (I understand some batteries have built in circuitry in it to help but don’t know for sure) 2) lithium barrettes can cause fire or explosion if exposed to air. I’m not trying to fry my passengers in some freak one in a billion accident. 3) it was lighter for sure, but I didn’t know if the 5 extra amp hours was with the risk for me.

ps your stock battery has a vent hose the new battery doesn’t so just tuck it in beside it.

 

[Spiffy]

Yea thats an issue with the underseat battery. What year and model do you have. Replace the aux battery and do a bms reset and your light will come back on. Also make sure you didn’t accidentally turn off the light on your overhead consul. It should be orange to match the other buttons not blue (off).

In another thread I started i asked about a bms reset. Does that reset do both the main and the aux battery at the same time? How would we know for sure since I can't read the the aux battery on any diagnostic tools I have. I have some high end scanners including fdrs.

 

[safety_3rd]

I think so… but I’m not sure. Some of the more involved members with forscan should chime in about increasing our internal programming to a higher state of charge (soc) but I don’t have any tuners.

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