Hey all - Wanted to get some guidance from those of you who have had your C8 for a while. I find that I drive my car once or twice a week as it is not my daily driver. I wonder if I should have it on the battery tender given how little I drive it. Anyone have experience with this? I realize if it's in storage for many months during the winter like many of our friends up north do it definitely makes sense but for me here in South Florida it's more about it being my weekend car and less about the weather. I just don't want to come out to a dead battery one of these days.

 

Not at all needed if you're driving the car weekly, or even every other week. If you start getting to 3-4 week increments then it's time to get the tender out.

 

Need it? Nah. Mine sits for a week at a time or more, no issues.

 

@Kracka and @tsigwing Thanks for the insight! Much appreciated!

 

Do you need it with your driving routine? No. Will connecting to a maintainer extend battery life? Yes, more than likely. An inexpensive but quality maintainer like a Deltran Battery Tender Jr. is all you need, not an expensive device with a C7 logo on it.

 

Really depends on how far you drive! 5 mile trip to the store uses more battery power than the alternator will replace!

Here is what I find, driving 3 to 4 times a week. On the 25 mile trip to town the alternator will read ~14.5 volts. It's doing all it can to charge the battery. If I have driven the day before still read 14.5 volts on the way to town. On the way back will drop to ~13 volts! The charging in the C8 as it was in the C7 is controlled by a computer. IF it's charge 80% it will lower the current to save energy.

Pic is from my C7 Service Manual. Charging was the same, controlled by a computer.

It notes with an 80% charge (since that is all it will charge to save energy) about 30 days is all you can bank on to still start the car.

For my street rod I installed a high amp alternator (125 amps.) Thought driving once a week would be OK. So to get the oil hot to evaporate most of the cold starting blowby water I have a 20 miles route I take. Battery died! Measured my parasitic current draw, which was about 50 milliamps. Then calculated starting power to crank the 8.2 Liter BB. At the rpm's I was using for that 20 mile drive looking at a graph of alternator output versus rpm I was NOT charging enough. Now the street rod with it's Yellow Top Optima AGM battery is on a charger 24/7! It does extend battery life as was mentioned.

Bottom Line: Depends on how many miles you're driving each week! I have the equivalate of the GM sold charger (bought on Amazon at ~40% of GM price.) Only use it occasionally as it's a PIA when I want to use the car I want to get in and drive! IF I used it once a week, I'd plug it in!

 

Sound advice given above.
In the end, purchasing a battery maintainer is cheap insurance against a bad surprise.