Just picked up my first vette this week. It is an 08 1lt 6speed. With the car came a small battery tender. That isnt the brand, its from drag specialties, which is a motorcycle retailer. I have the same basic one on my harley.
The car has the pigtail installed, so open the hood plug in the charger and go. Well with my bike, it goes to green quite quckly, and stays green-meaning fully charged. With the vette, it will occasionally flash green, but most of the time stay on red. On the charger that says that it means the battery is under 80% charge.
The only time the battery has been replaced that I can document was in 09. I bought this car certified pre owned from a chevy dealer, and asked them the age of the battery. The only answer I got was about their rigorous 172 point inspection.....
So, after all that. Is my battery tender too small, or is the battery going?
I think the battery tender would be sufficient, but I realize that there is alot more electronic things on the car than the bike.
Thanks

 

Hi, and congrats on your new-to-you Vette!!!

The Drag Specialties tenders/maintainers that I have seen appear to be a Battery Tender Plus unit just relabeled with a different sticker on it - so, it should be a very good unit.

But, I suspect it's a 1.25 or 1.5 amp "tender/maintainer" unit that really won't "charge" a car battery that is getting weak.

I've got a couple battery "chargers" that will put out 10 or 20 amps to actually "charge" a battery that is quite run down.

However, I have a bunch of the small tenders/maintainers on my bikes, Vettes, and emergency generator, and they work great on the small batteries, and also on the Vettes - if the batteries are in good shape to start with. I can hook them up and leave them attached for long periods and they automatically maintain the battery at optimum charge.

If your Vette battery is in good shape, then the 1.5 amp tender/maintainer unit should keep it fully charged.

My daily driver Vette gets plugged in every time I come home, and the light on the unit will blink for a half hour or so - not sure exactly how long, but when I go back out into the garage an hour or so later the light is steady indicating a full charge.

So....if your battery tender doesn't show a full charge after an hour or so, the battery may be getting kind of weak. It will take a looooong time for a 1.5 amp tender to fully charge a large battery.

I'd put a full charge on it with a real "charger", then after a drive hook up the tender. If the tender doesn't bring it back up to a full charge within an hour so, then you'll probably need a new battery soon.

Good luck, and enjoy your new Vette!!

Bob

 

If your tender is just a re-badged Battery Tender like BEZ06 said, the issue may be that your battery has too much sulfation to take a full charge. I do like the Deltran Battery Tender line, but one feature it does not have is desulfation. It was one of the main reasons I switched to BatteryMinder. Another popular one here on the Corvette Forum is CTEK which also has a desulfate feature. I actually bought a new 2013 Grand Sport which came with the Corvette battery tender which is just a re-badged CTEK.

 

I have a couple of these Schumacher maintainers:




They have a desulfation mode - here's what the manual says:


I use these on both Vettes and they work great to keep the batteries at a full charge.

$20 at Walmart.

Bob

 

There were a few detailed posts here recently from guys who'd contacted Deltran directly & were told their BTjr doesn't have the power (to get past the sulfates on the battery plates...or something like that), but that the Battery Tender Plus does. It was pretty definitive, however a BTjr's been on my '12 GS since new & seems to work really well, however I'll soon buy a BT+.

 

Thanks all for taking time to respond. Cant find a date on the genuine delco battery. But it is a 6year battery. I will try to charge up with a bigger charger, and then put it back on the tender and see.
Will it get past the sulfation with the bigger charger?
So far the little I have driven it, it has not done anything weird. Always started.
It is cold and salt is on the road, so I am not going to drive it anywhere, anytime soon.
One last question, if the battery is bad, what is the best battery for the vette? Optima?
Thank you

 

I had a red top in my 2005 for almost 4 years. No issues at all. I sold the 2005 but the battery was still going strong.

 

Have been using my HD battery tender on my Vette's Optima this winter, has been working great.

 

If you cannot charge your battery off of 2 amps, you need a new battery or have too much parasitic drain.

 

You're absolutely correct - the C6 doesn't work well with a weak battery.

It can take a loooong time to charge a run down or weak battery!!

Here's info about charging time for the 1.5 amp Shumacher pictured in my previous post:


So....a run down car battery can take a day or two to fully charge with a tender/maintainer.

Like I said in my previous post, my cars have good batteries, so when I come back from driving around town and hook up the Schumacher unit, the light initially is yellow, and when I go out into the garage a 1/2 hour or hour later the light is green indicating a full charge and that the unit is in the "maintain" mode.

Bob

 

So I took the battery out, and took it to autozone for a test. The test results showed full cold cranling amps, yet only charged to 86%. I have had this on the battery tender for several days. So, in a last ditch effort, I have it on the bench, with a bigger (6 amp) charger. Im going to let it go for 5-6 hours, and then try it again.
I am betting that all the battery will take is 86% and is getting weak.
Thank you for all the help.

 

86% is really pretty good. I would would not worry about it.

 

An end to this saga. After almost 6 weeks of trying a different battery maintainer(first was a tender jr., second was a schumacher), removing the battery, charging on the bench...
I finally bought a new red top optima.
Checked the charge, and it wasn't full when I brought it home. So, I charged it with a 6 amp charger for a while.....checked it, had a good charge.
Then I installed it in the car, and hooked it up to my maintainer. It would never fully charge.... Tried both again, nothing. This was a 3 day affair.
So today I bought a ctek3300. I installed the leads so that i could just plug it in.
And plugged in the charger. And it shows the battery needs charged. I'm thinking, here we go again.
Got some Adams car polish today so I thought I would try that. It worked very well. Would highly recommend.
Anyway, about 30 minutes after I plugged in the ctek3300, the green light comes on.
So the ctek,has an option for agm batteries. I'm sure many already know this. Took me a while to learn. Maybe someone else can learn from me.
I did it! Woo HOO

 

glad things worked out for you.

 

Just FYI- I seem to read and can agree that in C6 Vettes a battery will only be reliable for approx. 3 years. That means I accept the fact that every 3 years give or take I will buy a new battery. I think the C6 Vettes are just very hard on batteries, no real proof just my personal knowledge of my car and from reading battery posts on this forum.

If you always have a tender on your battery I bet you would get more life out of it. I choose to just use my tender in the winter months and during the "cruising" season I dont waste the time. Maybe once my garage is completed I will run a tender daily too. +1 to CTEK also