Considering I quoted post #5 and gave my reasoning behind a more expensive battery than a wal-mart special I don't need to read it again. I certainly trust and respect Bill's posts, he's helped me out countless times on other electrical issues. If I had no other accessories I would agree, but for an extra $100- over the course of 4 years (the FULL warranty period of this battery) that breaks down to what- an extra $25 a YEAR! Are we that really cheap? Remember I DO have extra loads to drive, an air compressor for my horns and a high powered stereo. Not to mention the walmart special is a lead acid battery, if it leaks your PCM is right underneath. I wouldn't use anything but an AGM style battery on this car.

OK I guess nobody has been paying attention- I have a high powered stereo system (3 amps) I can dim the lights on a C5 especially at idle. I also sometimes run this same stereo for long periods of time without the engine on particularly if I'm working on the car so I could use the extra reserve capacity. The C5 has a very strong alternator yes, but at idle speed the voltage drops a bit.

 

No, we're all paying attention! I think it's you who missed the mark with your battery choice. You chose an AGM type battery which produces a very good cranking amperage, but has a very limited reserve amperage capacity.

For your needs, a DEEP CYCLE battery would have been a better choice.
They have a far better reserve capacity, and can withstand many discharge and recharge cycles.

 

Oh I'm not paying attention? Check the ratings below and tell me which battery (in both sizes) is top rated for Life, CCA AND reserve capacity.

AGM can certainly do both, what do you think an Optima Yellow Top is marketed for? From their page "The YellowTop® high-performance AGM battery is one of the only true dual-purpose automotive batteries available. With premium cranking power and unparalleled cycling capability (rechargeability),"

In Consumer Reports the Sears AGM Platium battery is rated excellent in both CCA AND reserve capacity by a long shot, though one of the 2 most expensive. The Optima Red Top is second. I know not all of us like Cons Reports esp for cars but I think for stuff like car batteries their tests are good.



You're right there is no need for some super high output CCA battery just for starting. But no matter for now I think I found my problem, I left my line lock accidentally engaged which drained my battery

 

The Optima Yellow Top is constructed and marketed for DEEP CYCLE use.

The DieHard Platinum is only designed to be a stating battery, and not for deep cycle usage.

There's a BIG difference!

 

Make up your mind- you first say the AGM battery is for good CCA/starting only and have very little reserve capacity, yet the Optima Yellow AND Blue tops are all AGM.

http://www.optimabatteries.com/optim...etop/index.php

If we want to throw other manufacturers into the mix, here's another more AGM batteries deep cyclers. Exide Orbital also has AGM in deep cycle and marine applications.
http://www.exide.com/portal/server.p...na/221/orbital


http://www.odysseybatteries.com/ (which I use in my motorcycle)

"The Odyssey battery ingeniously uses absorbed glass mat (AGM) technology to offer, in one box, the characteristics of two separate batteries. It can deep cycle as well as provide enormous cranking power.

These batteries are capable of providing engine cranking pulses in excess of 2250A for 5 seconds as well as 400 charge/discharge cycles to 80% depth of discharge (DOD). A typical starting, lighting and ignition (SLI) battery can do one or the other, but not both.

Odyssey AGM batteries will do both - provide short duration high amperage pulse or low rate long duration drains."

____

But for aguments sake let's compare the reserve capacity Sears Platinum battery-
http://www.sears.com/shc/s/p_10153_1...o=2&blockType=
it has 135 minutes of reserve capacity.

A comparable Exide Oribtal AGM Deep Cycle has up to 100 minutes reserve capacity AND has less warranty.
http://www.exide.com/portal/server.p...uto_deep_cycle

The Optima yellow top in the same size (also has less warranty):

Part Number: D34/78 (8014-045)
YellowTop®; Deep Cycle Battery; UNBOXED; Group D34/78; Cold Crank Amps 750; Crank Amps 870; Res. Capacity 120; Ampere Hour 55; Top Terminal; L-10 in.; W-6 7/8 in.; H-7 13/16 in.;


So much for the Sears having "very little reserve capacity"?

 

If you can use top terminals, try a group size 24F or 34R. These battery group sizes are very similar to the 75/25 or 34/78 group sizes used in our Vettes and have reversed pos/neg terminals. Check the specs on the brand you like in order to get the most CCAs, etc. "Group size" has to do with the physical size of the battery ONLY and nothing to do with any of the electrical aspects. Just double-check the physical measurements to ensure it will fit the tray and the holddown, etc.

Some imports and most all Fords (for years and years) have batteries with the positive terminals reversed. Only problem is that no one to my knowledge makes a side terminal (GM style) battery with reversed terminals.

HTH

 

My Canadian 99 Vette was built in Mexico, Maybe some stuff is different.

John

 

BUILT IN MEXICO??????????????????????????????? wHAT?

 

Your VIN must be 3G1YY3----------- if built in Mexico,,,, 1st digit is country of origin 3=Mexico,2=Canada,1=USA

 

More old school thinking... if you think Im wrong, start your car and disconnect the battery. you could do that in your grandfather's 55 Buick.

 

My dealer said my Vette was built in Mexico. Maybe he was wrong. When I entered my VIN at a VID id website it came up as made in US. So i'm confused. I know that Caddys are built there so there may be some validity to it I'll find out.

 

Whats the size battery that you used? I'm looking for a replacement.

 

I used to have a '55 Buick! started the engine by pushing the gas pedal....strong as a Tank.

 

AND about as heavy as one.

 

Group 75 Battery is the correct one.

 

Can anyone tell me if its normal for the battery to lose charge or go dead if your car is not driven for 2-3 weeks??

 

QUOTE=87SAM;1574471676]Sounds like the battery is correct and your car is backwards. On my 2000, the negative is closest to the engine. The service manual also shows the negative closest to the engine.[/QUOTE]

The negative post on my 2000 Vert is closest to the engine..

 

ABSOLUTELY NOT! My 02 Z can sit idle for 30+ days on a 6 year old battery and still start the engine.

Conduct a battery current draw test and see how much parasitic current draw is being removed from the battery after the BCM goes into the sleep mode. It should be 25 milliamps or less.

BC

 

Ok will get that done. Any ideas on what could be drawing the current? Something must be. If car sets for 3 weeks the battery goes down.THe car does have an aftermarket sun in the trunk with amp.Maybe an under hood light switch or something.