Battery Tender
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Safety Car
Joined: Jan 2007
Posts: 4,735
Likes: 14
From: Visalia CA
Battery Tender
After I purchased my ’97 in January of ’07, I bought a Battery Tender and a new battery. I keep the car plugged into it when not in use. On average, I drive the ‘Vette about once a week. That Interstate Battery lasted six years.
My current battery (same make) was only three years old. Today, I got stranded at my local pizza shop. Fortunately, the owner was there and we tried jump-starting off his new Ram truck. No go. Two blocks away was an auto parts store, so I grabbed a new battery and dropped it in. Now, everything is good. Even the HVAC display that was not working before, is working fine.
The last time I drove the car, the voltmeter didn’t show anything unusual like the battery was discharged or charging. Am I needlessly using the Tender. It’s like you can have an old worn out battery and get a false sense of security that everything is OK.
Anyone have any experiences like this? And why wasn’t I able to jump-start the car?
My current battery (same make) was only three years old. Today, I got stranded at my local pizza shop. Fortunately, the owner was there and we tried jump-starting off his new Ram truck. No go. Two blocks away was an auto parts store, so I grabbed a new battery and dropped it in. Now, everything is good. Even the HVAC display that was not working before, is working fine.
The last time I drove the car, the voltmeter didn’t show anything unusual like the battery was discharged or charging. Am I needlessly using the Tender. It’s like you can have an old worn out battery and get a false sense of security that everything is OK.
Anyone have any experiences like this? And why wasn’t I able to jump-start the car?
Burning Brakes
Joined: Jan 2006
Posts: 788
Likes: 105
From: Olathe Kansas
The newer batteries just aren't that good in my opinion.
Interstates used to be the gold standard, but they are just average these days.
I wouldn't think you'd have to use a tender driving it once a week..
but it doesn't hurt anything at all.
Just be prepared to replace a battery more often..
You could check your volts at battery when engine running to
make sure your alternator is putting out
Interstates used to be the gold standard, but they are just average these days.
I wouldn't think you'd have to use a tender driving it once a week..
but it doesn't hurt anything at all.
Just be prepared to replace a battery more often..
You could check your volts at battery when engine running to
make sure your alternator is putting out
Le Mans Master
Joined: Sep 2003
Posts: 8,812
Likes: 2,029
From: eastern NC
Bill, did you have the recently failed battery tested? If so, what was the result of that test?
What is the model or part number of the battery that just failed? Not that it is important to the issue, but most (but not all) Interstate batteries are currently being manufactured by Johnson Controls.
I have a Battery Tender that has been on my riding mower (with the same battery - Exide AGM) for the past 10 years when it is not in use.
Here is some info that I pulled from the Battery Tender website that describes it's charging technique:
In most cases, a 12 volt lead-acid battery, at 100% SOC (State of Charge), will have a rest voltage between 12.8 and 13.1 volts. That means an effective float voltage need only be as high as 12.9 to 13.2 volts. However, most Battery Tender® battery chargers have float voltages between 13.3 and 13.5 volts. The important thing is that the float voltage should be higher than the fully charged rest state battery voltage and it should be lower than the gassing voltage which is about 13.8 volts. See the discussion about float charging on the Battery Tender® website. It is definitely worth your time to read that document.
What it is essentially saying is that as long as your Tender is not charging more than about 13.7 volts when connected it should not harm your battery.
I'm confident you already knew this, but just in case and to elaborate a bit on what 8VETTE7 said, the best way to utilize your Corvette's volt meter is to use it to monitor the health of you electrical system. If you have any doubt it your alternator is charging, all you need do is check the volt meter when first turning the ignition on. Voltage should read between 12.5 and 13.1 volts. Once the engine has started, voltage should climb to between approximately 13 - 14 volts. It should not read less than original battery voltage or more than 15 volts. If it does, it's time to investigate.
Good luck... GUSTO
What is the model or part number of the battery that just failed? Not that it is important to the issue, but most (but not all) Interstate batteries are currently being manufactured by Johnson Controls.
I have a Battery Tender that has been on my riding mower (with the same battery - Exide AGM) for the past 10 years when it is not in use.
Here is some info that I pulled from the Battery Tender website that describes it's charging technique:
In most cases, a 12 volt lead-acid battery, at 100% SOC (State of Charge), will have a rest voltage between 12.8 and 13.1 volts. That means an effective float voltage need only be as high as 12.9 to 13.2 volts. However, most Battery Tender® battery chargers have float voltages between 13.3 and 13.5 volts. The important thing is that the float voltage should be higher than the fully charged rest state battery voltage and it should be lower than the gassing voltage which is about 13.8 volts. See the discussion about float charging on the Battery Tender® website. It is definitely worth your time to read that document.
What it is essentially saying is that as long as your Tender is not charging more than about 13.7 volts when connected it should not harm your battery.
I'm confident you already knew this, but just in case and to elaborate a bit on what 8VETTE7 said, the best way to utilize your Corvette's volt meter is to use it to monitor the health of you electrical system. If you have any doubt it your alternator is charging, all you need do is check the volt meter when first turning the ignition on. Voltage should read between 12.5 and 13.1 volts. Once the engine has started, voltage should climb to between approximately 13 - 14 volts. It should not read less than original battery voltage or more than 15 volts. If it does, it's time to investigate.
Good luck... GUSTO
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Are there risks leaving a Tender attached - I suppose there could be since you are connecting an electrical device to the car. It just hasn't been a problem for me and my batteries have lasted 6+ years in both cars (current one still going strong). YMMV.
Burning Brakes
Joined: Jan 2005
Posts: 1,156
Likes: 88
From: Ohio (Go Bucks)
I just recently had to replace a battery also. I use a battery tender when I am not driving my car for a week or so and have had no problems. I did not get any indication that my battery was failing until one day it just wouldn't turn over. I checked and the battery was 10 years old.(definitely time for a replacement).
