My 2019 GS had been sitting in the garage for a week when I decided to give it a bath. I started it, backed it out, washed and dried it. Got back in it to put it back into the garage and it was dead as a door nail. At first I wondered what I could have done that caused it. I figured there was no way sitting for just 7 days the battery would be dead. But no, it was. I pulled out my extension cord, plugged in my battery tender and the lights said low battery. So I left it plugged in for about 30min., and went back out and it started right up. I guess it's time for new battery. Any advantage to getting an AGM??

 

I have heard mixed results with the AMG battery. Some swear by them, some people say it screws things up. There is a newer ACDelco 42 month battery.
Did you have the car on a tender most of the time? I think that is one issue having a car on a battery tender all the time. It wont give you a warning when the battery is getting weak. You could have very little battery life left, it will start ok coming off the tender but can die all of a sudden. Without a tender your battery will give you a warning when it is getting weak. It will turn the engine over but start getting slower and slower.

 

Most of the time it's on a battery tender. I figure after almost 6yrs. it's time for a new battery anyway. So, I'm going to just go ahead and put in a new one. I asked about the AGM's because I had 4 of them in my motorhome and they worked great. But I've never had one in a car, and with all the electronics I wasn't sure about it.

 

I posted the words below in another recent thread, which link to another recent thread... I will NEVER buy another FLA battery if I can help it.

Best is going to be Odyssey Performance by Enersys, but it will cost you.

Learn more: https://www.corvetteforum.com/forums...post1608345746

Modern day FLA (Flooded Lead Acid) batteries are a crap shoot at best. I have been cursed by the FLA gods and no longer purchase a FLA battery for any vehicle application. Not even my JD riding mower...

 

What is the big issue with the FLA battery. I have had them in all my cars for decades and never had a problem. But then I don't use a battery tender.

 

I've gad good luck with both types on all cars. AGM at the moment in the C7 & Explorer. And my mom's Hyundai.
Using Walmart's AGM's. Never had a problem.

 

Neither the C7 charging system nor the Battery Protection Package chargers support AGM batteries. Both can apply voltages over 15V while maintaining the battery, but AGM batteries are limited to charging systems where the voltage doesn't exceed 15V.

Bill

 

With all due respect, Bill, page 9 of the US 3300 Corvette Model 1051 Battery Charger manual disagrees.

 

Nortonco:
Is this the same as the GM Corvette Battery Tender (made by ctek)? model 20929740 ?

 

Nothing is wrong with them, unless you are in my life. I am cursed by the FLA gods and cannot get a FLA to last more than 3 or 4 years. I have switched to AGM batteries for all of my automotive needs and am currently on year 8 for two of those AGM batteries.

Bill, with all due respect, your post has inaccurate information, similar to the thread I linked above and here: https://www.corvetteforum.com/forums...post1608345746

The truth of the matter is that neither a FLA or AGM battery is designed to exceed a charging voltage exceeding 15v. AGM batteries can generally take a higher charging voltage (opposed to FLA) due to having a lower internal resistance. The same is true for amperage as well. Generally this is true because not all AGM batteries are created equally, as I explained in the link above.

 

Maybe the issue is leaving your battery on a charger it's hole life. Is it really necessary to leave your battery on a charger constantly? I keep hearing of issues from people that do. I don't hear from people that don't.

 

My C7 is not on a battery tender at all times when garaged. My C7 was delivered to me 23 Nov 2014, it is a 2015 model year. For all you naysayers out there it still has the original battery from the factory which is over 10 years old now and still going strong. So far not a hint of a problem, starts strong even after sitting for over 3 weeks at a time.

 

There you go!

 

My Autozone AGM has been working just fine for over a year now.

 

Yes, that's a CTEK US 3300 Corvette Model 1051 Battery Charger. A copy of the manual, with a diagram of one on the cover, is atchd here.

 

Well, here is one from a person that keeps the car hooked up to a battery tender all the time it is not being driven. I have had my AC Delco 42 month battery installed in the car since the spring of 2019 and not one instance of the battery failing to start the car right away.

 

FYI. I do have an AFM disabler plugged in all the time. I heard that it could be a drain on the batter when not driving. Is that enough to drain the battery in a week??

 

I had a disabler for about 2 years without a problem. I never took it out. I finally did the VLOM mod.

 

No. I was just unlucky with my parts store battery FLA purchases. That and they are made with less quality materials (recycled lead) in a lot of cases in order to generate more profit. For things like batteries, I have done the math and if I spend the extra money to buy a TPPL (thin plate pure lead) AGM battery from a reputable source (NOT Optima) like Enersys then I have saved time, effort and most likely money in the end.

As mentioned earlier, I am on year 8 (eight) for two Northstar AGM batteries. Northstar was bought by Enersys a couple years ago though and are no longer manufactured under the Northstar brand label. Odyssey Extreme or Performance is my #1 choice in AGM batteries at this current time in history. Those batteries were roughly 50% additional the cost of a comparable FLA at the time and have lasted twice as long as the FLA would have. This means that not only have I saved the hassle of having a dead battery twice, replacement twice (under warranty or prorated), but I am now in the money positive category for the reliable Northstar AGM batteries.

Buy once, cry once.

Again, there is NOTHING wrong with using an AGM battery in an automotive application (Corvette included) as long as the battery is of the same group and used for the same purpose as the OEM battery was. A different group size could work as long as the dimensions fit the confined space and the terminals were in an appropriate orientation.

 

There is no way to charge all the new battery technologies with one simple charger.

AGM batteries do not like going to anything above 2.5 volts per cell or they could pop their relief valve and release important regeneration materials. The standard GM Charging system charges a battery as if it were the Standard Flood Lead Acid. My Buick is now charging above 15 volts because of the colder weather and that won't fly with an AGM battery.

A battery's life all depends on "How Well or Completely the battery is charged over time". If you keep it fully charged the battery can last a long time. A new vehicle battery always seem to last a bit longer than the ones we get from the parts stores. I suspect it is a fresh battery they install and it is taken care of and charged every once in a while before delivery. The FLA has a fairly high Self Discharge Rate and this means it needs to be charged every month or two at the minimum. In many vehicles the battery never gets fully charged and this is means that we need to augment the charge by using a strong battery charger that can get your battery to 2.5 volts per cell (15 Vdc) which gets the battery gassing where the electrolyte gets de-stratified inside the battery case. A good solid charge is very important to making the FLA last longer. When a FLA battery is stored at a partial charge then you can start to loose capacity. I use FLA batteries for Power Storage in my RV and those are two very large 6 volt FLA batteries making 12 volts at 160 amp hours. These batteries use a LOT of water when charged hard so I installed an automatic watering system to allow them to stay "full" of electrolyte while staying fully charged.

The Absorbed Glass Mat battery covers a lot of different designs. There are so many batteries that are called AGM today. The AGM batteries are able to hold a charge longer as the self discharge rate of the AGM is half of the FLA battery. I used one in my RV and it went over 10 years in use where it sat and floated most of the time on a small 10 watt solar panel and a diode. The AGM is a great product but it needs more care when charging it to do it completely. Having a relief valve also makes the AGM a Valve Regulated battery as it fits in both categories. Any time you have a valve on the battery between the inside and the outside you need to charge it more gently with lower voltages.

LiPo batteries are a popular item and these offer some serious benefits. They can be made up from banks of 18650's or the newer larger version designed for the Tesla cars. These also require a different charging regimen from what the car is able to do. The LiPo batteries again require a specific charging regimen that our automobile alternators are not able to handle at this time. They make a lot of power and need to be kept cool in the summer and heated in the winter.

Overall I would have to say that the battery type our Corvettes were designed for is still the best overall battery to be used. The FLA is a well known item and there is lots of experience in making them and maintaining them. Doing the battery maintenance is part of my overall maintenance program. First I put on my rubber apron and eye protection! Electrolyte can blind you if it gets on the eye. Then I remove the FLA battery and wipe it off and clean the top and the posts. Check and record the voltage of the battery. Remove the caps over the cells and verify that the electrolyte is up to the proper level inside the battery. IF needed I add R/O water to top off the cells to get the electrolyte to the right level. Then I close the top up and charge the battery past 2.5 VPC and let it boil away to get a good full charge. After the charge I put the battery on the bench where it gets charged once a week.

Lithium Ferrous batteries are nice because they weigh very little but they are still not quite ready for prime time. I bought 2 and one lived, kind of an expensive way to learn. Great on a small motorcycle...

Until our automobile alternators are able to charge the various technologies simply by picking out the right choice battery I would hesitate to change the battery TYPE in the meantime. It won't be long before people offer alternators designed for the various types of batteries that are available. No ONE battery charger is going to be able to charge all the various ways the manufacturers want it to. I have chargers for AGM batteries and I have a charger made "just" for the Optima Batteries "specifically". The optima charger uses another battery in between the charger and the Optima battery to filter out the electrical noise that is being made by the charger. It seems that the Optima batteries might be more susceptible to the "noise" than other batteries.

Cheaper chargers CAN put out more electrical noise.
Cheaper chargers CAN Overcharge the battery by streaming a steady flow to the battery 24/7.
Cheaper chargers ARE NOT a good deal!

COSTCO sells the Interstate Battery line and they have the very best prices on quality Interstate batteries. The prices are roughly half of retail which makes them a great deal. After testing batteries for years I am familiar with which companies tell the truth about the capacity of their batteries. It would surprise many of you just which companies stretch the facts a little and who under-estimates the capacity and whose rated capacity is achieved after a few cycles. And knowing a little of the chemistry they are using on their battery plates helps me understand and predict how the battery will function in service.

Whatever you do, DON"T buy a battery because of the warranty! The warranty is just a gimmick to get you to buy another battery from the same manufacturer.

Recycle any old batteries you have to help clean up our world! Batteries don't belong in landfills!