Tell that to my wasted boat batteries

 

I'm thinking those golf cart batteries were non-sealed, deep cycle. The desulfate feature of modern chargers is helpful, but what saved those batteries was the design and intended function. Did you add electrolyte, too?

If you drain a sealed, lead acid, starting battery down to zero volts, it might never come back. With most chargers, you'd need to trick it just to get it started, or start the charge from a power supply or another battery. And the ampacity will be gone, even if it does hold a charge.

YMMV, but it's a lot cheaper to disconnect the battery when you store your C3, and test for parasitic loss. The voltmeter in a C3 isn't there just to fill a hole in the dash.

 

My understanding of lead acid battery tech is they all work the same way. The plates are just thinner with more surface area on a typical car battery. all the car batteries Ive owned werent "sealed" at all they had large plastic caps that popped off to reveal the same cells of lead plates and acid. Maybe deep cycle batteries have some reason they are able to be more easily recovered I dont know. but I have successfully recovered fairly new dead car batteries. The last one took my charger like 4 days in recondition mode but it worked. and I have never added electrolyte I had an issue with my alternator a few years back and it caused my battery to go dead enough in 2 days that the lights didnt even work.... That battery was only a couple weeks old then. Its still in my car and hasnt had an issue since I charged it.

 

i guess the desulfating charger really is magic!

 

That happened to me 35+ years ago. When I went to put a charger on the dead battery I put my hand down on the center glove box door and felt it latch down. The little bulb had drained the battery after a few days.

 

newbiec3r
Where did you come up with this "sequencing unit"? Post the reference. I am not sure what it is that you're writing about. I don't think I'm the only one here with that question. Nothing magical about this but gives us some feedback.

 

SEQUENCING UNIT is from a wiring diagram produced by classic car wiring . it involves lh seat switch, lh seat buckle switch and rear compartment lamp. also glove compartment lamp, rh seat buckle switch and rh door ajar switch . im not sure what the function is or where it is located,

 

A lot of the de-sulphating battery chargers are gimmicks but there are some that actually work to some degree. Once a battery has been exposed to discharged lead acid or air the battery will loose capacity for good. Lead plates that are exposed are not going to come back with any kind of battery charger. I spent years studying batteries for Westinghouse and the technology for re-charging batteries has improved but there are no miracle working devices yet. I have tested re-chargers that used PWM, shorts Bursts, Pulse charging and several other methods of de-sulphating a battery. Once a battery is dead it is important to get it on a charger right away to have the least losses in capacity. Once the lead has flaked away from the plates and is on the bottom of the container there is nothing in this world short of replacing the plates that will help that battery.

How a battery is charged is very important to the life of the battery. What the compounds used to make the battery are very important. The specific gravity of the battery is very important. When a FLA Battery is left discharged it immediately starts oxidizing the plates and the capacity is lost forever. You might get 80% or 90% of the battery to come back to life but I have never seen any totally discharged FLA battery come back to 100% of the rated capacity.

Many battery chargers will not charge a dead battery unless you somehow push some voltage into them allowing the charger to see something to start from. This is a trick that is well known and very useful. Recharging a Red-top or yellow top battery when very low is even more difficult. They sell special chargers for these batteries as they do not like any A.C. noise in the power going to re-charge the battery. It is suggested that you recharge them through a battery in the middle to filter out the noise that many chargers have.

Today many of the new batteries are labeled to be "Maintenance Free" which means very little other than they don't want to make it easy to access the batteries cells. Some of the newer batteries are using different compounds and they use less water than conventional FLA batteries. In the earlier days they used Antimony in batteries to strengthen the lead plates. This allows the lead attached to the plates to last a bit longer and not flake off as easily but the amount of antimony ties to how much water the battery will use. In the 1960's you were supposed to check the battery every few fill-ups to ensure that the cells had enough water in the electrolyte.
Our batteries today still use water in a lot of them but they don't want you to access the cells to replenish it and this makes you buy a new battery more often. Many golf cart batteries still use a large amount of water as they have a substantial amount of antimony in them.

The plate thickness and dimensions are not common to all FLA batteries. No two FLA batteries are the same and not all FLA batteries operate the same way. The batteries with longer warranties are frequently the same products just pro-rated. The batteries with the higher CCA ratings have heavier interconnects inside them allowing them to handle higher discharges without fusing or melting the parts inside of the battery. There are so many variables in the batteries made today and none of them work like the others exactly. I have a battery that came out of my wife's VW and it is a Enhanced Flooded Lead Acid battery or EFLA and they are designed for the cars that turn off at stoplights and restart hundreds of times while the car is being used. These batteries also use water in their electrolyte and they make it VERY hard to get into the cells by using a Valve regulated device to release the pressure inside the battery as a last resort and this allows the battery to re-combine the gases into water so you don't need to fill it as often.

Batteries are interesting devices and the technologies are changing rapidly. I have found that many of the common battery packs loose capacity if they are discharged 100%. Most of the Lithium batteries used in Tesla's and other electric vehicles use special software that disconnects them from the load before they get totally discharged. If they get totally discharged they like to catch fire and other bad things. The same goes for overcharging them, they have special circuits to protect the cells from over-charging as well. My favorite batteries are the ones I use in my RC aircraft, these tiny batteries are extremely powerful but have to be handled carefully and treated carefully or they don't last long. I stick with FLA batteries in all my vehicles except for my RV which has a AGM Absorbed Glass Mat battery for the starting and ignition and FLA batteries for the loads inside the vehicle. The AGM batteries have a very low self discharge rate which means you don't have to charge them as often.

 

I appreciate the replies but this has been happening since 1980 when bought .over the years it has had several batteries, a few new alternators and two new starters , I can’t believe it’s any of those since they have been changed several times over the years and problem has not changed. I’ve done the parasitic test where using multimeter And have individually pulled each and every fuse and plug out of the fuse panel, no change. About 15 years ago I had the entire vette off the frame to repaint it . I changed all bushings and suspension parts under it along with inspection of all sockets and hopefully all plugs and terminals. I even checked the path of the battery cable to be sure nothing was ever pinched. Remember this problem was from month I bought it , previous owner “ knew nothing about the problem” I have checked the battery on several trips. And literally the alternator is charging it. I can drive it all day and go an hour or two away from home and it’s fine . But let it park for over night and it won’t start with out a quick jump.I mean it doesn’t crank and crank it literally will fire right up with just touching the battery terminals . I’ve built 2 street rods and overhauled a 2910 wrangler so I’m not a novice, but I’m lost on this. Obviously I’m missing something simple and probably right in sight.

 

This is how I resolved the problem years ago but thought it’s about time I get down to the real reason not the bandaid solution . I’ve done the parasitic test so many time I can do it blindfolded. I am truly lost

 

FWIW, @jsz31 did create a new thread, here:
https://www.corvetteforum.com/forums...ver-night.html

I'd suggest any replies unrelated to the OPs issue get sent there.

 

Curious - what is the condition of your ignition switch?

I have dealt so far (many months since buying the car) with my random parasitic draw by installing a battery blade switch. This is my peace of mind on taking it anywhere where I don't want to not be able to start it. But it's a pain in da butt to have to remember to open the battery compartment each time I get in/out....

My gut instinct is that it might have something to do with my ignition. I know it does not move to the set positions with too much accuracy. In fact I can move the ignition towards the off position and pull out the key just short and it will stay running. I will change it out (assuming a straight-forward job) and get back to you if anything changes with battery staying charged.

 

I bought a new switch but haven’t installed , too many other thing going on. Vette is parked in garage for later when I got free time to tinker. Not in hurry