Or just leave it for now... I'm not sure. The temp here has not dipped to -20 C˚ yet but i expect that within 2 mths. My Multimeter currently says it's at 11.9V with the engine off. 14.3ish with the engine running idle with radio/AC off. 6mths ago the reading with the engine off was 12.3.) I have one of those 12V NOCO battery boosters (GB30). Can i just attach it to the battery cables right before i take out the battery, and leave it attached to the cables while changing the batteries to keep the current on so the electrical/codes don't get messed up? Hmm..

I don't drive the car that much.. Less than 15km a week. I've read i should drive around for 30min a few times a week to keep the current up which i will do.

 

how old is the battery? You can certainly attach an external 12V source to maintain voltage while changing batteries - probably a how to vid on Youtube. I'm more curious about how fast you are losing your charge to determine if you have a parasitic current drain or just an old battery. What happens if you put a full charge on the battery? I think an 80% charge equates to 12.6V and 100% is 12.8V (google for tables). If you put an aux charger on the battery does it go up to 12.6+?

 

The battery seems to be 5yrs old going by the stamp/warranty sticker i see on it. Its a AcDelco. 770 CCA. When i have the lights, AC and radio on it reads around 13.6v. I think my main problem is i don't use the car enough.

I have no warranty papers or anything related so i'll just pay the cost to buy and have the shop also install since i have no tools. I don't want to end up messing up the codes or shorting anything such as the temp sensor under the radio.. What pissed me off the other day is there seems to be not enough power to keep my Garmin nav on while i'm driving. The Nav gives me a 'Low battery' alert when i turn off the engine but the car dash says nothing. Just want to avoid losing all power during a trip. The car still seems to start fine.

 

So i took it for a spin for a little over an hr (The Garmin Nav was fine the whole time) and checked the Battery with a Multimeter as soon as i got it back home..

The reading i got after that drive is 12.4v!! (Up from 11.9) So that tells me the alternator is good and to take it for a 30+ min drive at least twice a week instead of just letting it sit too much..
going forward i will also keep the NOCO Booster in the car, keep my eye on the voltage level and hold off on getting the new battery for now.

 

you may have a parasitic current draw. You'd have to put a current meter on it to see what the car draws with the key off. You'd need to google for the spec but my guess is "normal" is in the 20-25mA range. if you are say at 50 mA, that would cut the time between charging in half.. Something small like a glove box light or a vanity light staying on can do that for you.

 

I will try that. Right now the only thing that seems to be on when parked is the alarm since all lights are off except the blinking red flash on the dash from it.

Took it for a 45min drive the other morning and i had to use the NOCO booster to start the car after it was parked for about an hr. Reading was 13.6v with the engine running when i got back.
Is there a way to turn off the alarm fully without taking out or disconnecting the battery? (To have no red blinking flash on the dash when parked)

 

I guess to answer my earlier question I've just read elsewhere to just take out the fuse for the alarm.

Got the 'Battery low' alert on the dash the other morning when the car wouldn't start. Used my booster to get it running. Battery reading with engine running idle was 14.3V.

 

Put in a new battery a few weeks ago.. Everything good so far for now.