Battery tender issue
Thread Starter
Instructor
Joined: Sep 2004
Posts: 139
Likes: 3
From: Rockland County NY
Battery tender issue
I bought a batter tender at Wal Mart before last winter and it worked great, keeping the battery charged for when I would take it out every few weeks. I didn't plug it in to the car at all after the winter but now I had it plugged in from a few weeks ago and the little light was green when I plugged it into the lighter so I thought the battery was all charged up and it would keep it that way. But now, it is really dead.
I thought it might have not made a good connection but all my testing showed that it did. So I thought the charge somehow burned out something over the 8 months of not being plugged in.
But when I opened the hood with it still plugged in, the little light went amber - due the inner hood light draw.
Can anyone shed any light on this?
I thought it might have not made a good connection but all my testing showed that it did. So I thought the charge somehow burned out something over the 8 months of not being plugged in.
But when I opened the hood with it still plugged in, the little light went amber - due the inner hood light draw.
Can anyone shed any light on this?
Team Owner
Joined: May 1999
Posts: 22,830
Likes: 13
From: Columbus Ohio
CI 3-4, 8-9-10 Veteran
St. Jude Donor '06-'08-'10
Does the car do anything? Headlights, starter?
If not, remove and clean your battery cables as a starting point.
Team Owner
Joined: Mar 2001
Posts: 54,124
Likes: 30
From: Cincinnati, Oh USA
Measure the battery voltage before connecting the tender. Then plug in the tender, if it is good, your voltmeter will show an increase in voltage and it won't be very much. Dead batteries read 12.0 volts or lower. Don't expect the tender to charge up a totally dead battery, use a higher current (like 6 amps or higher) battery charger. When the battery is charged up, try your tender again.
Thread Starter
Instructor
Joined: Sep 2004
Posts: 139
Likes: 3
From: Rockland County NY
Thanks for the responses but the issue is the battery tender, not the battery. Starter is a bit touchy lately so it needed an extra zap by turning the key a couple times to kick it off. But it doesn't turn over now and only minimal lights.
Question is why doesn't tender show any drain (amber light)? Lighter socket works cuz when I plug in cell phone charger, that works.
TIA
Question is why doesn't tender show any drain (amber light)? Lighter socket works cuz when I plug in cell phone charger, that works.
TIA
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Team Owner
Joined: Mar 2001
Posts: 54,124
Likes: 30
From: Cincinnati, Oh USA
The orange light comes on only with a certain amount of drain current and you don't know what that value is nor do you know what the drain is on your battery. Get a VOM (voltmeter, ohmeter, milliameter) and perform the test I already posted. You don't have to spend a lot of money for a decent meter, Harbor Freight sells a digital VOM for $8. With it you can measure the state of charge on your battery and its drain current and the current your tender is supplying the battery. If your tender supplies less current than the drain current, then it will never keep the battery charged up!
GM says the drain current should not exceed 50 milliamps. 12.0 volts and below, battery discharged, 12.9 volts and above, fully charged and linear in between.
GM says the drain current should not exceed 50 milliamps. 12.0 volts and below, battery discharged, 12.9 volts and above, fully charged and linear in between.
Last edited by jfb; Jan 4, 2010 at 12:22 AM.
Racer
Joined: Jan 2005
Posts: 373
Likes: 0
From: Lenexa Kansas
This may or may not be relevant to your issue, but is your 'battery tender' the actual trademark Battery Tender product or are you referring to any battery maintenance product as a battery tender?
I have only used the trademark Battery Tenders on my cars (hard wired), and have never had a problem. I sleep above one or two while in operation. I will never sleep above an $8 unit from Harbor Freight or Walmart. I have had a car burn up in my driveway, and I am not going to let it happen in my garage.
I have only used the trademark Battery Tenders on my cars (hard wired), and have never had a problem. I sleep above one or two while in operation. I will never sleep above an $8 unit from Harbor Freight or Walmart. I have had a car burn up in my driveway, and I am not going to let it happen in my garage.
Race Director
Joined: Jun 2009
Posts: 10,428
Likes: 9
From: Southside of Western Norte Americano State of Confusion, ColoFornia
St. Jude '13
This may or may not be relevant to your issue, but is your 'battery tender' the actual trademark Battery Tender product or are you referring to any battery maintenance product as a battery tender?
I have only used the trademark Battery Tenders on my cars (hard wired), and have never had a problem. I sleep above one or two while in operation. I will never sleep above an $8 unit from Harbor Freight or Walmart. I have had a car burn up in my driveway, and I am not going to let it happen in my garage.
I have only used the trademark Battery Tenders on my cars (hard wired), and have never had a problem. I sleep above one or two while in operation. I will never sleep above an $8 unit from Harbor Freight or Walmart. I have had a car burn up in my driveway, and I am not going to let it happen in my garage.
while it is convenient to wire them to the cigarette lighter plug.. this is forcing the charge to go back through the battery terminal connections, Which with a dirty connection will net you exactly these results. I prefer wiring the charge direct or clipping to the batt terminals themselves. (after all the battery is what you are charging)
Melting Slicks
Joined: Jul 1999
Posts: 3,214
Likes: 101
From: Decatur, Alabama
Thanks for the responses but the issue is the battery tender, not the battery. Starter is a bit touchy lately so it needed an extra zap by turning the key a couple times to kick it off. But it doesn't turn over now and only minimal lights.
Question is why doesn't tender show any drain (amber light)? Lighter socket works cuz when I plug in cell phone charger, that works.
TIA
Question is why doesn't tender show any drain (amber light)? Lighter socket works cuz when I plug in cell phone charger, that works.
TIA