moonshoxx

Just got car back from dealer fixing the valve spring break. They also put in a new Delco. Since the other battery only lasted 9 months, i got a "battery bug" to monitor. After driving for a week, the voltage on the battery bug shows the max 12.9 but the percentage is already down to 73%. Thoughts? Recommendations? Anything? Thanks

MGretz70

Alternator?

moonshoxx

I had thought that but it checked out fine. Also i guessed that voltage would be down if alternator was bad

AORoads

Someone needs to look for a short or a loose ground imo. Did they do that?

Knob Jockey

Do you have a multi-meter and do you know how to use it to check the current draw once the car has gone to 'sleep'?

About 20 minutes after shutdown the car should only draw a very small amount of current. I don't remember the exact number but I think it was less than 20 milli-amps. Try a search, this has been fairly well documented.

It's not unheard of for the C6 to have a 'computer' problem that kills batteries when the car is off.

This assumes you don't have any non-OEM devices plugged in/etc.

moonshoxx

Did not do that. Wouldn't that hurt voltage as well though. Since valve spring and now this I am ready to dump this sucker if not for set of brand new michelins I just out on

moonshoxx

Nothing else plugged in. Maybe the battery bug just sucks. That was bro opinion

moonshoxx

Related question. Is it too late to put it on tender. Car is dd but very short drives to work

AORoads

Ah! New news/information.

It has been said from Bowling Green that very short trips do not recharge the battery. Can you recharge the battery by putting it on a tender which is a brand name for a "battery maintainer"? Maybe. It depends on how discharged it is.

If deeply dishcharged it could take more than one day, not just overnight. Since it's a daily d., I'd get a proper charge, then use a "maintainer" of any kind regularly (could be every day, every few days, etc.).

Don-Vette

What he said ^

bolivar

I have no idea what a 'battery bug' is.

If you are seeing 12.9 volts on the digital display WHILE RUNNING, I don't like this value. Most cars will put out voltage above 13 volts while running.

If you see 12.9 volts while the car IS NOT RUNNING, this looks like a fully charged battery (usually max voltage is 12.6 volts after a battery stabilizes after charging.)

If you open a door, the car is going to take several minutes to totally go to 'sleep'. You will see lower voltages when various circuits are still 'awake'.

As someone else said, buy a multimeter and learn how to use the voltmeter part of it to get accurate voltages. Test the voltage at the battery while running and after the car is 'asleep'. If the battery drops into the 11 volt range, it probably needs replaced.

c54u

The battery nuts are tapered. Did the dealer put the same nuts back on and are they on tight to hold the cables.

SUB VETTE

What the hell is a battery bug?

moonshoxx

Battery Bug is a little deal that you wire to battery that tells you the voltage of battery and the percent of life left.

FortMorganAl

I had never heard of the battery bug either so I looked it up. Knowing how lead acid batteries work, I wouldn't trust the battery bug to know anything about the actual capacity of a battery although it would give you some useful information if you monitored it monthly for years. It would also be able to tell you that you had a dead battery but the ability to tell the difference between 73% and 100% is questionable.

As mentioned above, short trips kill batteries. Any trip less than 30 minutes is not going to fully charge the battery and this is probably what you are seeing. Get a tender and see what the battery bug says about that.