Jeff T.

I went out in the garage this morning and instead of the glowing green light the tender has the red light on and the green light flashing.

Pulled out the instructions and they say:

THE RED LIGHT COMES ON WHEN STORAGE
CHARGING BATTERIES:
a. The battery may be defective, take battery to the
dealer to be tested.
b. The battery has an excessive current draw, remove
battery from equipment.

The battery is a year and half old Delco. Anyone seen this before?

Thanks.

chris308

Have you checked to see if you may have a parasitic draw, something not shutting down when key removed.

Jeff T.

I have not since this just occurred. And to be completely honest I wouldn't have any idea what to do. Electrical is something my knowledge stops after sticking a plug in the wall.

whalepirot

Personally, I'd check battery voltage w/'charger disconnected and the electrolyte level. I've seen two batteries fried by trickle chargers one vehicle, with no unwarranted drains. My best guess was the normal draw of that car, to keep the collection of e-devices 'alive' was enough to tell the trickler to constantly recharge. Even the 1 year old Mercedes was boiled awy and unrecoverable. My only solution was to disconnect the (-) lead for long term storage, WITH the tender on the warranty replacement battery.

You'll still want to know about current drain with the car totally asleep; easy with a suitable ammeter momentarily in series from disconnected battery post to cable or using a clamp style ammeter. Someone here should post the 'normal' milliamp reading.

We all started there but with this forum and other online 'help', most electrical issues are relatively simple. Those electrons need a complete loop to circulate!

Loose or corroded connections, including grounds, are oft the problem while expensove to have a 'pro' find. Sometimes, it's an e-module at fault, but watching for a drop in high 'asleep' current, while systematically removing each fuse, can be a great step forward. Corrosion increases resistance to electron flow, but increases the current, which can damage sensitive components, even light bulb filaments, as trhe battery attempts to maintain rated voltage.

V=I/R or VR=I are simple equations, comprised of Voltage, Resistance and current(I). Alter the resistance; see the effect on current, with voltage constant. Too-small wires is similar and, according to my mechanic pal, is why so many newer cars have lights that don't light.

It is so hard to find a quality battery anymore, thoguh I've not used Delcos for a few decades. despite a great experience then. The lead content is minimal in most and they're made south of Texas.

Jeff T.

Time to go to youtube!

4theboy

Dumb question but was the light already shining steady green, then without doing anything, turned red on it's own and green light started flashing?

When first connected, mine will be solid red, while it is measuring. When voltage is almost where it should be the red will stay solid and green will start flashing for a short time until it turns solid green and red goes off. Any time there has been drop in voltage issue the red will indeed illuminate, but green has always gone off completely.

Jeff T.

Exactly!

Tied up with a bunch of stuff, but the battery just checked 12.47 volts.

mrlmd

That is a battery 70% charged. A fully charged battery reads 12.6-12.8 V, so the problem is either with your battery or you have an excessive draw somewhere, like a seat motor. Your charger is probably working fine. and is trying to tell you of some other defect.

4theboy

If all is working correctly the battery tender should have a float voltage somewhere between 13.3 - 13.5. Your voltage is close so your tender is probably trying to get there but not succeeding.

mrlmd

Be reminded that a battery tender is not the same as a battery charger - they only put out 1.25 V and will keep a topped up battery fully charged but will take forever (maybe 18 hrs. or more) to charge up a "dead" battery. Your charger is trying to work overtime to bring your battery up to snuff. Take your battery to a battery place or any service station or auto parts store and have it load tested. It's done for free because if it's no good they will want to sell you a new one.

Jeff T.

Update: Pulled the battery out of the car and put the tender on it. In half an hour I got both red/green lights again.

Taking it tomorrow to have it load tested.

Jeff T.

Took the battery to be checked at the local AutoZone. Failed.

30 month free replacement and I'm within that window and have the receipt.

Off to the Chevy dealer in the AM.

mrlmd

A battery must be fully charged before it is load tested, but yours is probably bad and that's what the trickle charger is trying to tell you.

Jeff T.

I had the regular charger on it overnight since I wasn't sure if the issue was the battery or the trickle charger.

Vetteman Jack

Good that your battery is still under warranty.

6speedsteve

I have one of these to check up on my battery at least once a season.

Jeff T.

Stopped at the local dealer and they replaced the battery no questions asked. Back in the car, tender on. Everything in my world is good for now!

pwrinkle

my half full battery icon is flashing yellow while the full battery icon is solid green?

grampi50

Why is the C5 so hard on/picky about batteries?

shaggyvette