[Havingfun]

Those CTec battery chargers and the ones with the Corvette emblems are pretty fancy, but I use a battery tender junior ($24.98 on line at Walmart) and it works perfect. As a matter of fact, I have used eleven (11) of them (boat, jetskis, lawnmower, motorcycle, generator, corvette, mule) for many years and never had an issue. I connected the quick-connect directly to the Corvette battery and the little pigtail sticks out from underneath the carpeting into the trunk (convertible). No messing with the cigarette plug in the trunk. I have the battery tender itself gplugged in the garage overhead at the garage door opener. When I pull in the garage with the Corvette, I pop the trunk and connect the overhead wire, which hangs down from the ceiling, into the quick-connect. I gently let the trunk lid down and voila... all done! And yes, the trunk light goes off after a few minutes. I swear by these simple cheap $25 battery tenders. Of course I do not have a Corvette emblem on mine, but perhaps I can stick one on there sometime in the future...... I am for simple, cheap and proven results!

 

[digitalstingray]

Same here, $14 unit maintains charge perfectly. Plugs into wall socket in garage. Bought it at Meijers store here in Michigan 15 years ago.

 

[kgrant (Kyle)]

Good Point Jerry and Havingfun,

I do have the Tenders that I bought from Sears on two of my other cars and have used them over the 15+ years and still working fine and I believe both were about $20.

Same here, $14 unit maintains charge perfectly. Plugs into wall socket in garage. Bought it at Meijers store here in Michigan 15 years ago.

 

[bob67327]

From another satisfied Tender user - our's is about as old as our 7 year-old C7 which still has it's original battery.

NOTE, please: I realize that I'm risking some gremlins by not replacing my old OE battery right away. I plan to do so "soon" but just haven't gotten around to it.

This time of year I drive 15-20 miles approximately every 30 days (when roads are dry in the Denver area). The car always starts as if the battery is nearly new. I wish I could crank the starter with the headlights shining on the front of the garage so I could see how much they dim when the engine is cranking. I can't recall if the interior "dome" light can be kept lit while the engine is cranking - I should check next time I drive the car, in a week or two.

Most of you Forum members are better informed than me. Have you suggestions about checking the condition of an old battery? I'm old and for many years that "lights on cranking" test was a very good indicator!

Wow, do I wish cars could still be started by rolling down a hill (ours is a M7).

It's my understanding that the majority of you think the most sensible battery replacement is with the OE Delco (?). Is that correct, please?

I've watched the videos some of you have provided showing the replacement procedure. Thank you very much for them; they will be helpful to me!

My plan (but plans aren't always realized!) is to connect a fully charged spare battery to the C7's underhood "hot" connector before disconnecting the existing battery. I know that the majority of you do not believe that's necessary, but I'll feel better knowing that I'm not letting the system go to zero volts and back to 12 volts. I also know that it's tricky to connect a battery to that underhood hot connector.

Before making that initial connection to the spare battery I'll check the voltage difference between that "hot" connector and the spare battery (with the ground side already connected). If the voltage is much different I'll probably borrow my neighbor's Tender and have both batteries "green" and then check for a voltage difference before connecting. I'm assuming they voltage difference between the C7 as it sits and the spare battery will be small, way less than a volt. If I do it with Tenders connected to both batteries, and showing their green light, I'd anticipate a voltage difference of less than 0.1 V.

Does anybody who is well informed wish to warn me, or advise me, please? Thanks very much to all of you! You've been helpful and I'm appreciative. warm regards, bob

 

[Z28+23]

I proactively replaced my OE battery at 48 months. Let my trusted mechanic do it. Went with an INTERSTATE AGM.

 

[bob67327]

Thank you, Z28+23. How do you intend to decide when to replace your Interstate AGM battery, please? thanks, bob

 

[jsvette]

Bob, a couple of thoughts: I'm not sure "the majority of you think the most sensible battery replacement is with the OE Delco" as many of us have replaced the OEM with other batteries including a large number of us who went with AGMs (see RedHot gets a battery for her upcoming 4th birthday there really is little gained by trying to maintain a charge while swapping out the battery and the potential for doing some serious damage by having a 12 vt battery to the front pos and neg terminals while doing it; other than anecdotal home methods for judging the state of the battery, unless you take it to a shop to have it load tested, it is a guessing game. Our C7s tend to develop a whole variety of electronic gremlins when the main battery is failing including: FOB isn't recognized, strange instrumentation readouts that randomly show up and disappear, slow engine cranking, loss of presets, etc.

 

[bob67327]

Thank you, Jeff. I've seen your very good, very helpful, video. I've watched it more than once. Regarding it, do you think it's worth buying a strap that lifts a battery by the battery posts, to remove the old battery? It would not be necessary to do that with a new battery - I'd place a think strap under the new battery to make lifting it out easy. Probably you suggested that!

I did know that many suggested using AGM batteries. Probably a majority of the best informed on the Forum suggested AGM's!

I certainly do know that there's a considerable risk in attempting to maintain voltage to the system when disconnecting an old battery. I take your opinion about that being unnecessary very seriously! It would make installing a new battery much easier!

It's most kind of you to warn an opinionated old man like me. I'm definitely more mistake prone now than I used to be! I'd be really mad at myself if I delayed replacing my battery so long that I incurred even a fraction of those gremlins!

I'd definitely like to hear you opinion about two things:

1. What do you think is the most "sensible" replacement battery?

2. If a "better battery" costs more but is nevertheless "sensible" to install, should one anticipate using it for a longer time?

I'm familiar with "load testing" batteries, but I'm not confident they make sense to use. Have you used them? Did they help inform you about replacing batteries in "ordinary" cars?

Thanks much! bob

 

[jsvette]

Thank you, Jeff. I've seen your very good, very helpful, video. I've watched it more than once. Regarding it, do you think it's worth buying a strap that lifts a battery by the battery posts, to remove the old battery? It would not be necessary to do that with a new battery - I'd place a think strap under the new battery to make lifting it out easy. Probably you suggested that!

I did know that many suggested using AGM batteries. Probably a majority of the best informed on the Forum suggested AGM's!

I certainly do know that there's a considerable risk in attempting to maintain voltage to the system when disconnecting an old battery. I take your opinion about that being unnecessary very seriously! It would make installing a new battery much easier!

It's most kind of you to warn an opinionated old man like me. I'm definitely more mistake prone now than I used to be! I'd be really mad at myself if I delayed replacing my battery so long that I incurred even a fraction of those gremlins!

I'd definitely like to hear you opinion about two things:

1. What do you think is the most "sensible" replacement battery?

2. If a "better battery" costs more but is nevertheless "sensible" to install, should one anticipate using it for a longer time?

I'm familiar with "load testing" batteries, but I'm not confident they make sense to use. Have you used them? Did they help inform you about replacing batteries in "ordinary" cars?

Thanks much! bob

Bob, thank you but I need to clarify a couple of things. I am, as well, opinionated but do try and rein it in and reflect collective wisdom of our great members here. Certainly don't always succeed .

-Any type battery removal tool (straps, claws, etc.) will make the removal of the OEM much easier since it is a tight fit.
-the most 'sensible' battery for you can be determined by how long you intend/expect to keep it (in your case much longer than the typical owner ) Factor both the years and warranty replacement and prorated run out vs total cost to help make your decision.
-I have only use load testing a few times. Since I live in the desert which is extremely hard on batteries, I tend to replace OEMs at a combination of it's warranty and first signs of issues. It isn't worth it to me to be stranded somewhere because I wanted to save a few dollars and try to max the viability of the battery.
-lastly, I did not do the video, rather I did the in depth 'how to' post with extensive annotated pictures.

 

[bob67327]

Thanks for your help, Jeff. I think your approach is more rational than mine!

We do plan to keep our C7 "forever" which statistically won't be long for us! We promised our grandkids we'd never sell it. But if AGW batteries last longer we'd be willing to buy one; we're willing to spend more to have longer service life.

However, from what you wrote, maybe we should buy the battery with the longest warranty? If replacement intervals are based on something other than testing (of some kind) because testing is impractical?

Have you yet installed a 3rd battery (a 2nd replacement battery, after the OE)? If you have not, have you already decided that you'll replace it by some specific date, independent of other factors?

Alternatively, maybe it makes the most sense to buy a cheap battery and simply plan to replace it every year or two?

I appreciate your replies; I'm trying to understand what is rational! thanks much, bob

 

[jsvette]

Thanks for your help, Jeff. I think your approach is more rational than mine!

We do plan to keep our C7 "forever" which statistically won't be long for us! We promised our grandkids we'd never sell it. But if AGW batteries last longer we'd be willing to buy one; we're willing to spend more to have longer service life.

However, from what you wrote, maybe we should buy the battery with the longest warranty? If replacement intervals are based on something other than testing (of some kind) because testing is impractical?

Have you yet installed a 3rd battery (a 2nd replacement battery, after the OE)? If you have not, have you already decided that you'll replace it by some specific date, independent of other factors?

Alternatively, maybe it makes the most sense to buy a cheap battery and simply plan to replace it every year or two?

I appreciate your replies; I'm trying to understand what is rational! thanks much, bob

Bob, to my knowledge, load testing does work but is also hard on an older battery. As to my personal approach, I tend to replace around 4 or 5 years and when I do it I go with a battery that carries a full replacement (non-prorated) for the first 4 years or so. Over 4 or 5 years, the difference in cost isn't that much IMO.

As to AGMs, they handle temperature extremes and vibration much better than flooded lead acid batteries, plus they are truly maintenance free.

And, no, I am still on the first replacement of the OEM in RedHot (7+ years).

 

[bob67327]

Embarrassed to admit it, but I've never even looked at my OE battery. I hope I don't find a terrible mess under that carpet!

I've only bought one AGM battery and it did last a really long time. It was in a '87 jeep that was trivial to "roll start" when the battery finally died. I think there was zero draw when the car was parked.

Our car hasn't been exposed to much by way of temperature extremes. We've had three straight nights of temp.'s below zero F but, of course, our car's inside (unheated garage, but attached and rarely below 32 degrees F).

You're doing me a service getting me "off dead center" and motivated to replace this 7.3 year-old battery!

 

[Racer_X]

Maybe i am an outliar but my 2015 is still happily running on its OEM battery w/tender. With that being said, its garaged, and not in a super hot or cold climate. I know if i was in FL (or NV like our buddy Jeff) i would have most likely replaced it at 3 or 4 year mark.

 

[bob67327]

Racer, where are you? We’re in Denver. bob

 

[rdslon01]

That's interesting Rodney. RedHot's (a 2014 like Kyle's) rear accessory plug receptacle seems to be very solid with zero deflection on putting the plug in or removing it. I wonder if they changed that area on your Z06?

For a part like the rear receptacle, to drive down the part cost by increasing the volume, there is no doubt in my mind but what all C7s rolling out of Bowling Green around the same time got the same part. They may have changed parts at some point, but it probably would have been across all model lines when they did it.

More likely, I think, is manufacturing variation. I probably either got a crappy mount, or ...

Anyway, it isn't worth it to me to mess with it. The CTEK plug is in, and has been for years. Having that comfort connect with easy disconnect is my solution. Therefore, the receptacle isn't something I normally think, or care, about.

 

[rdslon01]

From another satisfied Tender user - our's is about as old as our 7 year-old C7 which still has it's original battery.

NOTE, please: I realize that I'm risking some gremlins by not replacing my old OE battery right away. I plan to do so "soon" but just haven't gotten around to it.

This time of year I drive 15-20 miles approximately every 30 days (when roads are dry in the Denver area). The car always starts as if the battery is nearly new. I wish I could crank the starter with the headlights shining on the front of the garage so I could see how much they dim when the engine is cranking. I can't recall if the interior "dome" light can be kept lit while the engine is cranking - I should check next time I drive the car, in a week or two.

Most of you Forum members are better informed than me. Have you suggestions about checking the condition of an old battery? I'm old and for many years that "lights on cranking" test was a very good indicator!

Wow, do I wish cars could still be started by rolling down a hill (ours is a M7).

It's my understanding that the majority of you think the most sensible battery replacement is with the OE Delco (?). Is that correct, please?

I've watched the videos some of you have provided showing the replacement procedure. Thank you very much for them; they will be helpful to me!

My plan (but plans aren't always realized!) is to connect a fully charged spare battery to the C7's underhood "hot" connector before disconnecting the existing battery. I know that the majority of you do not believe that's necessary, but I'll feel better knowing that I'm not letting the system go to zero volts and back to 12 volts. I also know that it's tricky to connect a battery to that underhood hot connector.

Before making that initial connection to the spare battery I'll check the voltage difference between that "hot" connector and the spare battery (with the ground side already connected). If the voltage is much different I'll probably borrow my neighbor's Tender and have both batteries "green" and then check for a voltage difference before connecting. I'm assuming they voltage difference between the C7 as it sits and the spare battery will be small, way less than a volt. If I do it with Tenders connected to both batteries, and showing their green light, I'd anticipate a voltage difference of less than 0.1 V.

Does anybody who is well informed wish to warn me, or advise me, please? Thanks very much to all of you! You've been helpful and I'm appreciative. warm regards, bob

I replaced my battery when the car started acting funny. That was back around August 2019, I think. My memory is bad, but maybe "acting funny" was it didn't want to start, but then did. Anyway, I remember where I was ( South Charlotte) when it "acted funny". I was happy that I was able to get it to start on its own and drive it back home to deal with replacing the battery at my leisure in my own garage.

I thought about replacing it with an AGM, but decided against it. The fact that an AGM nominally uses a higher voltage to charge than a standard lead-acid battery steered me away from it. I understand fully that people have used AGMs with their C7 for years, but the charging voltage AGMs prefer isn't what the C7 was designed for (at least not nominally, although it may very well be the case that the AGM charging voltages fall within acceptable tolerances).