boatman

I am sure this has been answered many times. Chevrolet went thru the whole system check. All OK. Put in new Delco battery, new GM alternator, belts fine, stayed fine for 6 weeks. Car is 89R.
Not driven often, but a least 20 miles once a week.
Yesterday, dead battery. Put on charge for 10 minutes, starts right up.
Dash reading shows 14.1 - 13.9 - 13.1 charging, etc., this is right after charging and stays that way while driving.
Come back home, stop the car. Five minutes later, battery dead again.
I have tried the float, trickle charge, stayed on 48 hours, no help.

It has been doing great, keeping a charge, then suddenly, dead.
Any suggestions? Do a good deep cycle 10 amp charge for 48 hours?

Boatman

silver84

The first time the batt went dead,
just before that, did you have a float charger
hooked up? If so, could the FC maintain 13 volts?
You should not let the batt go dead.
Do you own a digital voltmeter?

boatman

Negative on the float hook up. I can purchase a voltmeter. Thought of that, one thing not in my toolbox. After new battery installed, all fine for 6 weeks. You saying I should have maintained the battery with float charger after new battery in ?
Thanks for reply, looking for fix,
Boatman
Hobe Sound, FL

runner140*

Sounds like you drive your vette once a week for 20 miles. In the next cycle, after you have a good battery, try driving 2 or 3 miles three times a week. You lose approx. 1% a day and could be more. After seven days, you could be down 7 to 10 per cent of your battery. Either drive more ofter or buy a Battery Tender. Ecklers sells them for $49.99 part number 26850.

boatman

Been into C-3's for years. Only one C-4 in the past. Looks like I will get a voltmeter today. My neigbor has same car, drives it everyday, rain or shine, no problems with battery. Does driving every day make that much difference?
Boatman
Hobe Sound, FL

Vette Show: Fort Pierce, FL, about 12 miles north of Stuart, Rt 1.
Register at: www.stuartcorvetteclub.com

newbecorvetteguy

I know you said you replaced the battery, but it still sounds like the battery or it's connections to me. The bad connection can actually be inside the battery. I don't think it's possible to cycle from dead to fully charged to dead again to charged enough to start again in that short of a time. Mine was doing something similar last year before I replaced the battery.

jfb

Whenever you have a discharged battery it should be charged for at least 24 hours. You can tell the state of charge by measuring the battery terminal voltage several hours after it has been last charged. 12.0 volts or lower, discharged. 12.9 volts or higher, fully charged. You really need to measure the leakage current with everything off. This can be done with VOM (voltmeter, ohmeter, milliameter), your next tool purchase. Disconnect the negative cable from the battery and connect the VOM set up as an ammeter in series between the battery negative post and the cable. After the courtesy lights time out, measure the current. It should be less than 50 milliamps. My 87 measures 27 ma. But first, check at night for the underhood lights, the vanity mirror lights, the console compartment lights. Do you have an aftermarket alarm? or a radar detector or a high power audio amplifier? If so, check them for current leakage. If you have more than 50 ma. of leakage you can find the circuit by watching the ammeter while pulling fuses one at a time. The fuse that causes a dramatic drop in current is the one that will need further investigating. As the passenger door has to be opened to remove fuses, remove the courtesy lights fuse first so you don't have to wait for it to time out after each fuse pull.
I would think that with low leakage current and a 20 mile drive each week would keep the battery up. Harbor Freight sells a battery tender for $7 I believe. If you already have a battery charger you can buy an interval timer (turns your home lights on when you aren't there) and have it charge your battery each day for its minimum interval (usually 15 mins). An hour a day won't hurt your battery.

rws.1

The Harbor Freight Float charger has been on sale for as little as $5 and works just fine!
I have two... and bought additonal ones for my Brother's ATV.
Best investment under $10 I have ever made.

SilverBeast

If the battery went dead 5 minutes after you stopped, it's a bad battery. If the battery is OK, but still won't start, it could be corrosion inside those pretty black and red plastic ends on your battery cable. The plastic hides corrosion really well.

boatman

Silver Beast - You may be on to something there, and I value everyone's opinion, but the Chevy dealer said nothing about that. It is very humid here in south FL. Rainy season now, then some days, very hot and humid. This 89R sits in the house garage, covered. The garage is not temperature controlled.
I have a small building in the back that I keep radio control equipment in, with air and a de-humidifier. Get a large one for the garage where this car sits may help.
Thanks for reply,
Boatman