acnburner194

Hello!


My C7s car battery looks like it died. Can’t start, I can’t use the fob to open the doors, etc. I’ve connected this battery tender/charger for about 8 hours and so far still no luck. Going to give it some more time to see if this works. Does anyone know if this is able to bring a dead battery back to life and if so generally how long it could take to be able to start the car or enable some power at least?

Tinkertech

Usually you need to use a normal charger not a maintainer to charge a very low battery.

If the battery is extremely low when measured with a DVM (ie: < 5-7 volts) then it usually can't be brought back to life and needs to be replaced.

Most maintainers and chargers need to see ~ 3-5 volts before they will start their charging cycle.

Jeff T.

With all the electronics in these cars I would just pop for a new battery rather than trying a to resurrect a dead one.

Grand Slam

Have you tried starting with the fob in the steering column to verify it isn't a dead fob battery?

Power Hawk

I doubt that a battery tender will recharge a dead battery. Might be time for a new battery.

Rush91

Get a new battery......Even if you fully charge the battery, you will run into the same issues down the road. And yes, battery tender will charge a dead battery. Slowly but it will.....

acnburner194

I appreciate all the input. I’m most likely going to replace the battery but going to try to borrow and use a real charger just to see if it works. Sorry if this is a silly question but do I need to disconnect the batter to charge it with one of those chargers that you plug into the wall?


Also what would be the correct C7 replacement battery to purchase? I’m looking to go to advanced auto parts somethin this afternoon

sorry again for the silly questions and once again appreciate the help!

rfh928

I haven't had to replace my battery yet (coming up on 5 years) but will likely stick with the original Delco. As far as charging, you don't have to disconnect the battery to charge it...just hook up the + and - terminals and plug it into the power outlet.

CraigStu

I just bought a Diehard Gold from Advance for my 19. A perfect fit.

Grand Slam

Costco also has batteries that fit. If interested use their website to identify which one.

Vetteman Jack

Have the battery load tested at a dealer or auto parts store. They can tell you whether it is still good or not.

TraceZ

There is a point during the charge and discharge of a battery that voltage may be right to cause relays to hum/buzz. This is very bad for them, it causes arcing on the contacts and leads to premature failure. It can also impact other electrical components.

If your battery is discharged, disconnect it from the car before attempting to save it by recharging it. Only after it charges and shows a normal voltage should you reconnect it to the car.

DGA3

Did you have a Costco auto shop employee replace yours?

I'd be a little scared that he would mess something up!

joeking

Most battery tenders are about 1.5 amps or a little more. You need a real battery charger to bring the battery up to full capacity. Those little 1.5 amp chargers take about 2 days to even charge a riding lawn mower battery. They are more of a battery maintainer to keep a fully charged battery up to it's peak charge at all times. I have seen dead batteries come back to life and I have also seen them not take a charge. Put a real charger on it and see if it works and if not just get a new battery.

Tinkertech

When you do try to charge a dead car battery start with a low current ~10 amps.

High charge rates are bad for a discharged battery and can also cause the battery to burst.

vader86

The maintainer won't bring back the battery, time for a new battery, and leave it on the maintener then.

Red86Cfour

Disconnecting the negative battery terminal is pretty easy. If its that low I'd disconnect the negative, and use a real battery charger, not a maintainer. They're not called a charger for a reason.

roadbike56

My battery went completely dead over the winter. When I charged it with a full charger, I removed both the positive and negative leads. It's a PITA, but I did not want to risk any possible damage to the electronics in this car. BTW, I didn't replace the battery because it's only 18 months old. It's worked great since being recharged.

Bill Dearborn

A 3 amp maintenance charger will take a long time to charge a car battery. If the battery is dead you need to start at a low current level and let it charge for 4 or 5 hours to bring back some capacity, then raise the charger's current level and let it charge overnight. I use the following charger to keep my trailer battery charged:

Schumacher Electric SC1280 Fully Automatic Battery Charger and Maintainer for Motorcycles, Power Sports, Lawn Tractors, Cars, SUVs, Trucks, and Boats, 15 Amps, 6 Volt, 12 Volt, Black, 1 Unit


Earlier this week my Tahoe's battery got low enough that the solenoid could only click when I turned the key while the power seat would surge on and off. I charged it overnight at 15 amps with the charger above and the Tahoe started right up.

As for which battery is the best to put in your car go with the AC Delco Gold 42-month warranty battery.
GM Part # 88866309
ACDelco Part # 48GHRA

I found the dealer would install it for about $60 more than I would pay O'Reilly Auto Parts to purchase and install myself. I have a bad back so I let the dealer do it as my medical insurance copay is $40. None of the auto parts stores in my area will install a battery in a C7 Corvette.

Bill