Hi everyone

It's time for a new battery.
My 8 year old battery is at it's end. When I start the car one time and let it sit for a day in the garage afterwards, it is inpossible to start the car. It won't even turn ones.

I looked on the internet and the forum and Optima batteries are easely available here in Belgium.
I will go for the dual post-type, because of the ease of charging in the winter (and not having to remove the battery from the car).

1) What Optima dual post battery would fit the rear battery compartment?
2) Yellow or red?

 

Novushu,

If you look at Optima web site they state that the Yellow Top is a deep cycle batt.

What uses a deep cycle and when or why?
A camper that can not recharge soon.
A boat with inboard motor but no alternator.
A trolling motor on a small boat. Run them all day long, then charge at home.
Lawn equipment w/o a alternator.
Some golf carts.
Some forklift trucks.
So, any application that is out in the field working / supplying 12V but absolutely no charging available.

Deep Cycle battery is designed to be run right down to near death. Then charged over & over & over again later on, without any harm to the battery. Its what they do.

So, there is your answer about the Yellow-Top in a C3.

 

I use a Deep cycle battery in my C3 Corvette and it works just fine for a standard battery. The deep cycle battery can function as well as any other battery as long as it has the cranking amperage to still start the engine when you need to. I have a 1968 427 with high compression but use a gear drive which reduces the current draw on the battery substantially and my deep cycle battery never lets me down. The reason I use a deep cycle battery is because my cooling fans will run on after engine shutdown to cool down my engine and the two of them have been know to run 10-15 minutes after shutdown. I don't need a deep cycle but I wanted some better cycling than a standard battery might be able to provide long term.

Deep cycle batteries are able to go to a deeper state of discharge than regular batteries can. Generally 80% depth of Discharge over a specified time like 12 hours duration. A standard battery could not cycle that deep of a discharge over and over with the plate grid that they use.

The Optima batteries are not your standard Flood lead acid battery. They are a spiral wound Absorbed Glass Mat Valve Regulated batteries and have very unique special requirements for charging them to get a long life from them. I bought one over 25 years ago and it failed on me while using it inside a Cadillac STS and it failed on the road one day. I called the people I know in the battery industry and asked what they might know. Turns out that Optima makes their own series of battery chargers made for their batteries. I bought one just to see what it does, it delivers smooth clean power to the battery by running it through another "battery" before reaching their battery. I would be guessing but I would guess that they don't like any kind of AC wave forms in the charging power. They essentially cleaning the power that is going to the battery they are charging.

The Flooded Lead Acid batteries that came with your Corvette might be a less expensive way to start your Corvette. The alternator in your C3 knows one way to "charge a battery" and that is only for a flooded lead acid battery. The alternator can charge other types only because their charging requirements are similar to the requirements of the FLA battery.

Where you might have trouble with the AGM batteries is going to be the charging system will likely overcharge the AGM battery and cause it to "pop" the proprietary pressure valve releasing the recombination materials needed to keep the system operating properly. The trick with Valve regulated batteries whether they are AGM or AGM Spiral bound is when it pops, the valve opens allowing it loose important materials out. You never want any Valve Regulated Battery to "pop". A FLA battery would simply use a bit more water from the electrolyte when it is overcharged, this can be replenished in a FLA battery but not a AGM or other technology out there.

During the cold winter days the charging system, can and will push the voltage up near 15.5-16 volts and this will kill a AGM battery after any time driving it. The only AGM battery I tried, died because of the wide charging parameters of the FLA being done to the AGM batteries over the year. The GM dealer laughed furiously after learning that the Optima battery left me stranded, I pulled out the Delco battery and put in the Optima instead of following their recommendations. I deserved it.

I personally go out of my way to buy a reputable FLA battery from VARTA if I were in Europe. VARTA makes some amazing batteries that have really long lifespans. A Sonnenshien Battery from Germany is another great product. The Optima will work but it will be a compromise for the battery. On many Corvettes people have had some amazing life-span stories about their overpriced beauties. Me, I tested batteries for years and I know who tells the truth and who doesn't in that industry.

 

I use a yellow top & totally happy with it. Sits all cold winter long in NY & ALWAYS starts right up !!

 

i don't have a c3 but a yellowtop lives in my c5

 

I'm searching for a dual post battery and looked on the VARTA and Sonnenschien website. I could not find any. It seems Optima is one of few that the dual-post style in the EU.

I have a question regarding the 'damage' that can be done to the Yellow top AGM battery:
Is that when hooked to the alternator while the car is running?
Or does it only occur when hooking the battery to a battery charger that's not specially designed for the Optima (for example in colder periods of the year)?

 

The Dual Posts are a real benefit! I use them as well on my C3 because of the convenience. Just be sure that you can disable the battery quickly in case of electrical fire. With two paths of (12+) current you need to completely disconnect both paths from the battery when in an emergency. I have a Marine (Boat) Grade Circuit breaker on the lines coming out of the battery and they are both opened easily in case of need.

The damage to the yellow top Optima battery does not happen under normal circumstances. It will usually happen when it is very cold and when it is extremely HOT as the temperature compensation was designed for the FLA battery. The issues that people have had with them is likely from alternators leaking too much alternating current into the DC output lines or are overcharging the battery. My 2005 Buick will charge batteries up into the low 16 volt range as I have seen it, do it. This high a voltage for any extended time will kill a valve regulated battery by causing it to pressurize the inside of the battery and popping the relief valve. I just replaced my alternator after witnessing 16.5 volts displayed on the dashboard and replaced it with a new unit.

The potential for damage is because of the way our alternators were designed to charge a FLA battery. The FLA is a much more forgiving design than the Optima Spiral Wound Absorbed Glass Mat batteries are. If your alternator is not set up properly or even bad, it could over charge the Optima battery and cause it to pop a relief valve which hurts the battery.

Your new Optima will have a good long life under normal conditions. Keep it clean and charge it completely every so often. If near an engine and it's heat then you might consider a reflective blanket on the battery to protect it from the heat. My under the seat battery compartment is also insulated as well. I have the battery sitting in an isolated, insulated box with a vent tube to keep the air safe.

AGM batteries seem to last longer when kept cooler versus the heat of the southern or western parts of the United States.

If the car goes someplace where it is very HOT or extremely COLD then you might have issues. Use a multi-meter set on Alternating Current and check the output of the alternator on your Corvette. The alternator should be producing Direct Current as used by the car but sometimes they leak a bit of Alternating Current. Using a multi-meter set on AC you should be able to see any AC power heading for the battery. If there is any measurable amount of AC then you might have to replace the alternator.

I use a small 20 watt solar photovoltaic panel and a simple Pv charger to keep my battery floating (@14.3 vdc)all year long while not in use. Batteries in many cars are never fully charged while being used in a vehicle. They still need to be topped off with a charge every so often. On an FLA I would charge it every couple months where the Optima AGM battery can go longer between charging. The Self-discharge Rate for a FLA is more than twice that of an AGM in many cases. The AGM is better at holding a charge longer without any extra charging. This is why I have one on my RV with it's Ford V10 because I forget about it and it still works. If I ignored re-charging the FLA I might damage the cell by letting it start to oxidize which causes the current capacity to drop.

You were asking about the differences so I am trying to enlighten you a bit. I hope that your Optima battery lasts a long time for you and your Corvette! Try and find the freshest (most recently made) battery you can find, buy from a company who sells lots of optima inventory. Many battery manufacturers put date codes on their battery products. After getting your new Optima battery be sure to charge it up completely and start using it only after it has been fully charged.

Should you buy a Yellow Top over a Red Top? This is where I would suggest you stick with the Red Top unless you have loads on the battery when the engine is not running. Those two are very similar in the way and materials used to build them. Here in the United States I can buy a brand new Interstate Battery with dual posts for $130 with core. More and more companies are using the two post design.

Is this information any help to you? Just know that you should have a good experience with your new Optima battery. If a FLA battery appears with dual posts then that might be a less expensive option which would work as well.

If you take care of the battery, It will take good care of you!

 

As stated by Optima, its a Deep Cycle. A car will never need a deep cycle battery unless the ALT has been removed for unknown reasons.

Consider the Yellow Top a mobile source of 12V. You can take it anywhere by carrying it, run it, discharge it all day long. Thats why they are great for campers, 5th wheels, boats, etc that have no charging system.
Then later, bring the Yellow-Top home and charge it up again. This can be done numerous times w/o damage.
Deep Cyle means run it until dead, charge it, start over.

As far as electric fans still running at the radiator for a few minutes, I get that. But still, any common battery should be used to that in the summer.
There are millions & millions of modern daily drivers out there right now that the fan stays on as you walk away from the vehicle, on a hot day.

You can purchase a Yellow Top and install it. But you are defeating the purpose of its design in a vehicle with a "full-time" charging system.

 

The Red optima has 2 different Duel post batteries options group #34/78 and the group #75/25. The 34/78 has no bottom clamp hold down provision for securing battery.
The 75/25 does. The 75/25 has 720cca where the 34/78 has 800cca.
Personally, I would look for another manufacturer as the current optima is not the same as years past. JMO...

 

If you are referring to moving south of the border, I think that issue was remedied years ago.

I got 13 yrs out of my Red-Top. I swore up & down it was dead.
Took it to the store as a core for a new one.
Come to find out, my old battery was still in excellent shape.
It was something else defective, oops. Duh!

As far as the clamp provision, never gave it a thought until I was installing. Got lucky, it had one.
I would be very-very concerned if no way to clamp it in other cars, under-the-hood, etc.
But with the tight confines of a C3 battery compartment, it's not falling far.

 

The Yellow Top Optima may indeed be a Deep cycle battery but it cannot "be discharged until dead" and simply restored to the original capacity by a good charge. Even deep cycle batteries have their limits, they are not infallible and DO have their limits. The typical Deep cycle batteries are tested to 80% Depth of Discharge and they can usually provide 600-800 hundred cycles at 80% DoD before failing. The shallower the discharge the longer the battery will last. I was looking for the battery information showing the discharge curve which helps me understand the battery better.

A deep cycle battery has heavy enough internal buss bar construction to make it work for cranking a large engine when cold. This is something that varies from manufacturer to manufacturer as they all have different designs for the internal buss bars they use. Starting, Lights and Ignition batteries like those used in a car all have their own internal designs, the heavier the internal buss bars the more current the battery is rated for in the starting application. This is why they sell the same battery with different length warranties on them.

The choice of using a Deep cycle or an SLI battery is really up to the owner. Having an active cooling system to help my engine means I will have loads when the engine is off. The loads are easily supported by the deep cycle battery. In FACT it is the better battery for the particular job.

The battery industry has changed and become more consolidated. The players in the industry have had some crazy regulations put on them by the tree huggers and Congress. When you buy a battery today, part of the price is set aside to pay for the reclaiming of the useful materials from the dead battery. This is one of the reasons battery prices have gone crazy.

Here in my home we check our automotive batteries electrolyte levels every few months to ensure that the battery is in the best position to live a long life. This allows the FLA batteries I use to last several years and cost a fraction of the Yellow Top.

AGM batteries will always do better in a cold environment as long as they are charged appropriately. With a lower self discharge they do well in cold environments.

I do not want to start a conversation with everybody telling me how long their battery lived. There are a lot of fish stories when that starts up. My AGM in my RV went for 11 years of abuse and it was a nice battery although expensive. Is the extra time worth the extra money?

 

Novusuhu,

I know this thread is dying off. But I just found this info and wanted to inform you of an important issue between Yellow Top & Red Top Optima Batteries.

I was curious if my Red Top purchased in 2020 still has warranty or not.
Looking at Optima web site its states:
Warranties: Non commercial, passenger & truck vehicles.

Yellow Top 24 months.
Red Top 36 months.

 

I have owned my yellow top for 13 years and never had one problem

 

When I worked for a certain company which owned Optima, I only bought yellow-tops (corporate discout). They were like $50 at the time ..lol. So I had like 6 of them in various cars at one time. Depends on the climate a guy lives in ....but for me, they typically lasted me 13-14 years. No kidding. I still have one more left in a vehicle. But I know a guy who got about 14 years out of a couple red tops. He used them for racing.

OTOH, I regularly get 9-10 years out of Lead Acid Batteries in our area. I took a L/A Interstate (industrial) battery out of a skid steer which was 14yrs old. So, L/A is a pretty good value if you don't need Optima features. If you go L/A, you want to look for top quality premium batteries that use virgin lead and new acid. The premium batteries cost more, but all you have to do is look at the weight. They have more supports internally, and thicker plates. Costco has great prices on Interstate batteries which is a great value. The savings could be almost worth the membership price. The OP probably doesn't have a Costco there ...unfortunately. We happen to live in a climate which batteries last a long time. In the S. or W. batteries crap out after 5yrs ..if even that long.

The Yellow top batteries definitely use new lead and acid. And they way they're made their coils fit tight in their cells (like having good internal supports). I like that Optima batteries are nice and compact and don't spill or corrode all over the place. The Red is probably the better value between the two. But if cost isn't as big of an issue, I'd go yellow.

 

The same company who makes the Optima batteries offered me a senior job in their R&D section via one of their vice presidents. It would be nice to get a corporate benefit like that, cheap batteries...

My job was working directly with batteries and "learning" how each type work. I would use a PC and run tests to verify the capacity using electronic loads doing both Discharge Curves as well as re-charge curves at various rates to really understand the battery. I tested dozens and dozens of batteries from all over the world. I soon learned that some companies were a bit more "Honest" about the facts regarding their batteries. I also learned how to make a battery work for many, years in the deserts of the Middle East where a normal battery would barely last 18 months. I spent a lot of time doing this and with the data we were able to charge our batteries more effectively.

Being someone who worked with and tested batteries as part of my living I am still a huge fan of the good old Flooded Lead Acid battery, simple and cheap to make. A Proven design that goes back to before Edison. When they finally make an alternator that can charge an AGM battery effectively as well as a LiFe without having to replace parts. The charging program would be very different for the optional battery technologies so it could charge them properly. Today our alternators are still designed for use with a FLA battery, I have not seen any other yet. The FLA charge settings in the alternator can work with a Optima or AGM battery but will not be treated most effectively.

 

Yeah ..it was I bought a couple Optimas for buddies. The price to employees seemed to escalate over time. A regular LA battery was like $30 as I recall using the corporate discount. But we all paid for it with corporate nonsense ...that every company has. The good the bad.

Very interesting your story. Thanks for sharing!

 

Nothing wrong with flooded lead acid batteries. But I prefer that style either away from me, like in a trunk.
Or under the hood of a pickup truck with a thick firewall between us.

Just listen to those words:
Flooded, not good.
Lead? Good grief, poison.
Acid, worse yet.

All those lovely chemicals just inches away from your ***!
Oh, thank God there is a thin piece of fiber board and some plastic on the seat-back to keep you out of harm's way.

 

What bout that highly flammable gas in the tank not too far behind the seat?

But I get your point. That's the nice thing about an Optima. Plus they're nice and compact.

 

I hear ya.
But the gas tank is steel on all sides.
The battery box is cardboard on the sides.

I have seen old style battery explosions. Plastic case shrapnel flying, acid spraying.
Not purdy.

 

Optima batteries are absolute crap. What was once a very good product is now just another battery. I used to buy nothing but Optima batteries,they would last at least 5 years,the last I bought went 2 years and died,no more Optima batteries for me.