Opinions please: 2018 V6, proactively replace a 70k mile, seven year old battery or wait for battery failure?
If later, how would one know battery failure is imminent?
If replacing proactively, how much ($) would it be? Suggestions on brand and CCA? Is this a good option: Interstate MTP-94R/H7. AGM. 800 Cold Cranking Amps, Group Size H7. About $275 Autozone. Dealership $900++

My indie is very good, five years and counting. I don’t think I need to go to dealership.
Work commute is highway speeds 20 minutes Plenty of time for battery full charge.

Thank you.

 

BLUF. Time for a new battery. My thoughts:

Safe to say that the battery is aging gracefully, had a few like that. They never seem to fail gracefully. For me it is usually a cold dark rainy night and the wife is driving it. The story never has a happy ending and she never forgets it.

My "general probability" theory for my 12V batteries is, the probability of battery failure on month 1 is the lowest likelihood through to about 36 months (linear between 1 and 36 months) after 48 months the likelihood of failure is ever increasing.

In the past, 12V starter batteries under the hot engine hood and extreme heat and cold used to beat the heck out of batteries. I changed them at 48 months no matter what. We now protect them from those temperature extremes and subject them to significant demands serving 20, 30, 40 modules' demands. Industry for decades has called for moving to higher voltages.

Lastly, How much is a tow home? How much is a tow to a shop and stuck with having to buy their preferred battery and installed by someone with limited knowledge, and....drum roll please....

A new Walmart AGM H7/H8 will run about $200 (with tax) with a full 3 year warranty. $200/(7*12) = $2.38/month. It is not worth much to me to make the $2.38 get smaller with ever increasing risks associated with battery failure.

Indie might charge $150 labor.

https://rennlist.com/forums/diy-caye...nt-access.html

 

Much obliged for a thoughtful and thorough explanation. I’ll talk to my indie Monday.
I know this battery replacement is not easy. Seat removal or tilt, cut carpet etc. Porsche engineers really did a “marvelous” job in the battery placement. An item that needs to be replaced. Again, thank you.

 

My 2013 (with the original battery) was showing 11 something volts before startup.

I replaced it with a Costco Interstate "preemptively" for the exact reasons that @CAVU stated.

It was $215 (my labor not included)

That is for 7 more years about NOT worrying if it will fail at the least opportune time !

Paul

P.S. I still have the old one in the garage. It is holding 12.4v after being charged a few months ago.
I use it when I need a 12v source

 

It is not SUPER hard, but entails everything you listed.
I tilted the seat into the passenger backseat footwell (If I remember correctly disconnecting the seatbelt was too much work?)
Just leaning the seat backward (after removing the hold down bolts ) didn't give enough room.

Paul

 

If you don't drive your car much you might consider a trickle charger to keep the battery charged and fresh.

 

Thanks. Mine is a daily driver. 20 minutes or so highway speeds. Battery fully charged.

 

I did the Walmart AGM H8. think 200 like stated above. Fairly easy install. I did program battery with icarsoft v3 but not required. Definitely get a new battery, these things hate an old battery.

 

Thank you!

 

I also carry one of those small charge packs to cover emergencies if my battery or someone else’s fails. They are really small now and will start most vehicles to at least get you home with enough charge on the failing battery to keep things running. Costco always has nice ones about $70.

 

Thank you. In your experience, do these charger packs work? My neighbor has one and it would not charge (help start) another neighbor’s Jeep Wrangler. My power cord was not long enough for the standard battery charger.

 

The duralast H8 AGM I picked up from autozone recently had a Made In Germany sticker on it

 

Yes they work. I’ve used mine 5-6 times even after the device sat for a year maintaining full charge. I tarted my boats V8 one time.

 

Spoke to my indie. He told me the best battery is AC Delco. H7. I trust my inde. He’s always been conservative but not aggressive about replacing parts. Kind of person who checks the cabin filter and blows out debris rather than just replacing. Or superglue a cracked reflector rather than replacing whole assembly.

 

H8 is a little bigger than H7 and typically has more cca. This is just an observation, but generally bigger is better. You can find H8 for the same price as H7 ... that's why people go with them.