grantv

I stopped driving my car for the winter 11 days ago. Today I cleaned out the garage to get it in there before it snows. Go to the car, no response at all from FOB. Open the door no lights. At the suggestion of many here I bought a Battery Tender Plus recently so I hooked it up at ~11AM, it is now 5:20. Nothing. No interior lights, no FOB, parking lights, dash lights, not even a glimmer.
I did a search and see some people not being able to start their car, and no lights at first, but no sign after over 6 hours!? The battery cables are connected.
FWIW, there is a light clicking sound under the hood while charging, close to the front of the engine compartment.
Ideas?

65GGvert

Measure the voltage on the battery. It's probably dead. I came out last week to the same symptoms and the battery read 3 volts. It was 2 months old, I took it back to Autozone and they put a tester on it, said "do not recharge-defective".
Check the cables and check the battery. A battery tender won't recharge a totally dead or defective battery, it is intended to keep a charged battery from discharging when sitting with the current draw a car (particularly a Corvette) puts on it. It could take days, if ever to charge a dead battery with a battery tender. Again, measure the voltage on the battery first thing.

grantv

Thanks! Wouldn't the tender provide enough juice to light up an interior light? Also, 11 days ago she started every morning without a glitch (well, except some days I did get the remove key for 10 second warning). Obviously I'll have to remove the tender before testing battery voltage? Leave cables connected?

tbrowne

Not necessarily. Recharge the battery with a decent charger then try again or try another battery. 11 days is long enough run down a good battery in a C5.

65GGvert

Doesn't matter, just measure the battery with a voltmeter. I bet you find it's between 2 and 4 volts, or zero. Look under the battery, see if you have acid buildup on top of the computer and wires below. Maybe you won't, but look anyway. Post back what voltage you measure.

grantv

5.1V with the tender still hooked up. Didn't test after removing, but new battery being bought tomorrow. And I have read about looking below, will do for sure (was going to anyway!). Thanks everyone, never had a car that zeroed out completely from a dead battery.

bob guzzy

If a battery is under voltage a batter float charger will not keep it up, if the battery was low when you put the car away the charger would do anything.

The battery has to have at least 11v, under that the charger will not work.

You might only need to charge the battery, it's worth a shot, then you might be able to buy a battery on sale over the winter.

martysauto

I have gone 2 weeks without driving my car and no battery tender. It still cranks over no problem as it should. A 25-50ma draw will not cause a no start let alone a stone dead battery after 11 days. Either you have a parasitic draw or the battery took a crap.
Most any small charger will not work on a battery that is stone dead. You will need to remove the battery and take it to a shop be charged and tested. If it tests good, check and record voltage. Should be about 12.6v, let it sit a few days disconnected and recheck it. If it's low, the battery is junk, if not start looking for a draw.