blassy

Was away a couple weeks - returned to my car that wouldn't start....battery totally dead. 997.1 Carrera.
Managed to push it out of the garage and jump the fuse to open the hood but when I tried to jump start it...nothing. Couple sputters, sport chrono spinning and nothing.
Tow truck just left with it on a flat bed. Hopefully a new battery will be the cure to all....hope and pray that is.

911searcher

Maybe get one of those trickle chargers ? If you are gone for a few weeks ?

I might have just bought a battery and dropped it in to see if it was that

Philster

Since you're here, you're open to criticism: Should have bought a new battery and dropped it in.

No need to make a simple issue complicated.
.

7391420

These cars do tend to eat batteries if left for weeks.

I have a cigarette lighter trickle charger that works great. I don't leave it on all the time, but if I don't use the car for more than week then I will use it

ADias

About 1Ah/day. A charged battery has anywhere from 50 to 80Ah. Two weeks eat up 14Ah.

OKB

yea, I agree. its easier to take the battery to the car, than to take the car to the battery

Nip are

Have you already done the alternator cable fix? If not look into it. A bad cable will prevent full charging leading to premature battery failure. It's common on the 7.1 cars

blassy

Happy to wear the dunce cap here...but in my defense....
Wife was gone with the kids for the weekend in the other car and everyone I knew was at work. Couldn't get to the store and the mechanic is only 10 minutes from my house. It was the easiest and most expensive option but had my car back in a couple hours.
Back now and happy to be reunited.

yashagrawal

As a side note, yesterday my car was parked out in the sun 112F day, the battery was toast in the evening, had to flat bed it to dealer. Battery was original, 4 years old, 2 years in Nevada.

Petza914

Seems like they eat more than that idle for 2 weeks. Is the 1 Ah/day value with the car locked or unlocked, as locking it is supposed to put it to sleep and lower consumption when idle, but I'd bet that almost any 997 left idle for 3 weeks won't start. From your numbers, that would be 21 Ah down from a 50-80 Ah battery, so about 25-45% of capacity. At what percentage of charge will a Battery not start a 997?

If mine will be sitting for even a few days, I plug it in to the Battery Tender.

ADias

I think that the 1Ah/day depletion rate is with the car unlocked. Slightly less when locked with 2 clicks (long second click).

At what percentage of full capacity does a battery die? It depends on its level of sulfating. A sulfated 50% charged battery may not start. A highly sulfated battery may not start when the car sits for 2 weeks.

Sulfating occurs very quickly. Easy to check measuring the battery voltage. Anything below 12.4V (with no load) and sulfating has started. Low sulfated batteries can be recovered with pulsed current waveforms like CTek uses every time it starts:

911searcher

This may be happening to me.
Is it a big fix ?
Would this be hard for a mechanic to pickup ?

North Shore 911

My 2010 C4S Cab is still on its original battery. It's my DD, and I average ~12k/year primarily commuting plus an occasional run up to our lake home (650 mile round trip). I've never had a problem with the electricals (it was CPO'd through April '16), but I'm wondering if I should proactively replace the battery just to avoid any potential problems...

What's the best suggestion for a replacement battery for those who have swapped theirs out?

tomc_mets

I'd drop it off at dealer, enjoy some snacks and espresso, and ogle the pretty cars at the dealership. But, that's just me...T

AreaOne

I just replaced mine a week ago in my 2007 (and it was the original) with the Walmart Maxx