12v Aux Starter Battery Replacement

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Chrispy44

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Joined
Aug 6, 2018
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No stores around me (Cleveland, Ohio, USA) had the 12v battery match. O'Reilly's had this Super Start Platinum AGM Top Post Battery Group Size 51R - 51RTPLT battery for $245. Everything fit perfectly except the vent tube hole was too small. I used a 5/16" drill bit and carefully made the vent hole larger. It probably should of been a metric size for a better fit. I just wrapped the vent tube male-end with some plumbers tape to get a more tight fit and then put duct tape around once inserted to hold securely in. Everything seems to fit once I did those things. I needed a 10mm long socket for everything but the back storage compartment needed a Phillips head screw driver. I hope this info helps someone. My local dealership wanted $426.60 for just the battery not installed.
 

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No stores around me (Cleveland, Ohio, USA) had the 12v battery match. O'Reilly's had this Super Start Platinum AGM Top Post Battery Group Size 51R - 51RTPLT battery for $245. Everything fit perfectly except the vent tube hole was too small. I used a 5/16" drill bit and carefully made the vent hole larger. It probably should of been a metric size for a better fit. I just wrapped the vent tube male-end with some plumbers tape to get a more tight fit and then put duct tape around once inserted to hold securely in. Everything seems to fit once I did those things. I needed a 10mm long socket for everything but the back storage compartment needed a Phillips head screw driver. I hope this info helps someone. My local dealership wanted $426.60 for just the battery not installed.
Thank you for his post for outlining the procedure you used for the vent hose and the photos.

What Year is your Vehicle?
 
My 2022 has the same battery installed.

Re: the vent tube, the seller seems to suggest that it is not required. From the product q&a:

My Tesla M-3 has a vent tube attached to the factory battery. Why doesn't this battery have a vent opening for that tube? Did you sell me the wrong battery?1
answer
O'Reilly Auto Parts - RQ · 11 months ago
Hello and thank you for your question. This replacement battery is an upgraded AGM style. Unlike conventional lead-acid batteries, AGM batteries do not require external ventilation. However, it is still essential to provide adequate space and ventilation around the battery to ensure efficient heat dissipation and maintain optimal performance.

To ensure the best product fitment, we would need to know the year, make, and model of your vehicle as the correlating part fits multiple different vehicles and may have different outcomes for the answer depending on the corresponding information.
 
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In UK the original Yuasa aux battery is between £150 - £200. Not many are in stock in UK, but managed to source one for £165 (with blacl friday code) and fitted it yesterday. I would have alternatives if it was lot more money. Seems like a lot of tinkering to get other batteries to work and also worryingly a lot of people are going for Non AGM with breather pipe hacks. Not a risk I wanted to take with my family.

Original lasted 12v aux 9 years and was still going strong, but after a 12v start issues, I decided to swap.

It didn't lose radio settings, but I had to set close mirror on lock and it was tried to navigate my old address.

I think I have lost approx 20% SOH. Not bad after 9 years I guess.
 
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