jefranks

Have a '12 GS with a Chev battery tender that came with the car when purchased in May 2012. Just put in my first replacement battery. Performed by local Chevy dealer. Mileage is only 7,500. Drive a "bit" on weekends.

Plugged in battery tender last Sunday when I covered the car for the week (always garage kept). Checked the battery tender this morning to insure it said that my one week old new battery was fully charged. To my surprise it said the battery was NOT fully charged.

Called Chevy dealer to ask if this could be a battery tender issue or something more serious. (They are going to get bank with me on this next week.) The Chevy dealer supposedly checked the electrical system out when they replaced the battery because the car was totally dead and would not start with a battery assist or by jumping.

Suggestions? Is there a way to test the battery tender to see if it is working properly? The car is under factory warranty.

Thanks.

Travelor

I believe that the charger you got with your car is a CTEK Multi US 3300 just marked as Corvette or Chevrolet. I bought and use one but not from Chevrolet for my 2012 Corvette GS. It periodically cycles from green to amber in the "full battery" mode (see the owners manual).

If you are referring to the amber light associated with the full battery indicator, it may be not a charge problem. The tender goes through cycles not associated with charging to assure your battery is "healthy". This is a cycling thing, not necessarily telling your there is any problem but is "pulse maintenance" or "pulse maintenance" . The Chevrolet dealer may have sold you an old battery that is requiring a lot of "desulphation".

See the Owners Manual here
https://smartercharger.com/wp-conten...US-3300_us.pdf

Hope this helps.

George

jefranks

Thanks. Very helpful. The tender that came with my Covette is a CTEK, but is a slightly older model that the picture you posted.

jefranks

Think I have it figured out. I have the tender in the car connnected to an extension cord through the window. Since the doors are electric, it uses power to open the doors. Thus, when I enter the car and look at the tender, the 1/2 battery symbol is lit, not the full battery symbol for a full charge because it took a small amount of power to open the door. However, I finally looked at the tender through the window BEFORE I opened the door and the green, full charge symbol was lit. But immediately when I punched the key fob to unlock door, the full charge symbol changed to the charging symbol. I hope after a few minutes, the full charge symbol will show. Hopefully!!

69 L46 4 Speed

I plug mine into the cigarette lighter and run the cord out under the door. There is a notch in the door sill that the cord fits in nicely and you can leave your windows up. My CTEK sits on the garage floor. I still have the original battery in my 13 GS with 36,000 miles on it. The lights will cycle from Green to Amber often.

pickleseimer

I have a number of the 'retail' CTek 3300 units, and this is exactly what they do on all the cars I use them on. Opening the hood or doors, unlocking using the key fob etc all cause the CTek to go to a step less than full charge and then back to full charge depending on how long the battery draw lasts, usually a few minutes.

cclive

Yup, you're absolutely right. Remember that when you open the door, you turn on a bunch of lights but also the computer wakes up, some dash lights go on, etc etc. There is a big drain on the system from just opening the door, more drain than the tender can cover for, so the battery voltage drops below what the tender thinks is a full charge. This is completely normal as the tender can only put a out an amp or two but opening the door could add maybe five or more amps to the battery load, so voltage drop is the natural result.

flyeri

If you want to be certain your battery is good go to Advance Auto or such and have them check it. That will tell you if your battery is up to its advertised capacity. I use a Battery Minder and opening the door does not send it from maintenance mode to charge mode as if the charge is low. If I leave the door open for a few minutes it will. Your charger may be somewhat more sensitive.