Need to replace battery in 68 327/350. If I fully charge it, in a few day's not capable of turning over. Any other suggestions appreciated. Check for leakdown ? and how to do that Opinions on which is most original in appeartance please ?

 

If your car doesn’t get driven everyday, the AGM type batteries seem to hold their charge longer. Theses batteries are more expensive, but changing batteries in C3 cars is no walk in the park. At least with a convertible, you can put the top down.

 

Ya it would s**k in a coupe. Fortunately my 68 is a convertable so not to bad !

 

if 5 years or older probably time to change.. to test charge fully and pull off cable for few days and try again.. that will confirm drain.
these batteries are cool.. but expensive.. or i would go costco walmart..
https://www.corvettecentral.com/c3-6...ry-electrical/

 

Check for a draw in your system. Unhook the negative cable (safer)...and hook a test light up in series....one end to the unhooked cable and the pointy end to the battery terminal. Does the light come on? If so....start pulling fuses out of the fuse box until it goes out, then troubleshoot that circuit. If it doesn't light up......then you have a battery that has a bunch of dead cells.
I just get the cheapest battery that fits for my 72' 406.......it has plenty of reserve power and lasts just as long as you take care of it.......on mycar, I have a blade style disconnect that is undone everytime it sits.......bought the last battery in 2017 and it is still in there.....I put a light charge on it every once in a while.
As far as originality goes.....nothing looks original now and it is hidden so get what works and go with it. There are original batteries available but big $$$$$.

Jebby

 

Before you do anything, I'd have the battery "load" tested to verify it's condition.

 

thanks,
all comments will be checked, thanks for the explination of leak testing. and I will put in a shutoff. Any opinions on battery tenders / trickle chargers ?

 

I have a very low opinion of battery tenders and/or trickle chargers. If I need to charge a battery, I pull it out of the car and charge it with a battery charger, or a lab power supply.

Not sure what you need for a 68, but this is the (not very quick) disconnect I have in both of my C3s. I've had the cars sit for 6 months, reconnect battery, pump pedal twice, and start with a bit of cranking. No trickle charging needed. I may have needed to buy a bolt to make it work with the side terminal batteries.

 

I don't use trickles either...batteries on a shelf at the parts store have a shelf life of 3 months or better and it will in your car too if the battery is disconnected........if it goes longer, I just throw a charger on it for a couple of hours and forget about it again.

Jebby

 

People misunderstand a Battery Tender / Trickle charger. Does it charge? Yes. Will it charge a battery in a few minutes? No.
The name of these units is misleading. Its actually a Maintainer. Its job is to maintain the battery to 12 volts. If the voltage drops, it trickles the voltage back up to 12 again, but slowly. Then it shuts itself off and monitors the voltage.

I love my Deltran Battery Tender. It does an outstanding job. However, its only used during storage of a vehicle.
If you have electrical gremlins, it's not the battery maintainers design to fight off parasitic drains.

Another issue is people work those battery tenders to death. They plug them in, run them 24 / 7 for months on end and wonder why it died. The tenders do not need to be worked constantly. And if you think the tender is not doing anything after a full charge, grab the unit. It's still warm to the touch. It's still working needlessly even with the green "standby" indicator light on. Its still running.

A better solution to add longevity to the tender, is to limit how long it has to be activated. Walmart sells a 24 hr dial timer. (Its for turning on a light in your house) It has 48 notches, each tab represents 30 minutes.
The tender will come on, check voltage, then shut off in 30 mins. Just 30 mins a day.

 

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[I have my 82 CE on a trickle charger controlled through a timer. On for 2 hours a day and off the rest of the time. Battery is 5 years old and still works perfectly.

 

Walmart Ever-start battery and a "Battery Minder" 1.5Amp. Over five years now, no problems. But you may have a parasitic draw (test by pulling fuses) or an old weak battery (check the date code on the battery, if over five Y.O. get a new one). And lastly, check battery with a hydrometer, you may have a dead cell.
P.S. I do like the timer arrangement for the battery tender mentioned above by Headsup!

 

It's A LOT easier with the left T-Top removed. Almost as easy as a roadster.

 

I've had the same battery tender for 10 years with no issue. I can start my car 24/7 with no issue. Accidentally leave a battery charger on too long and you can boil your battery.
Changing a battery in a c3 isn't tough try a c4.you get to take off that fender panel.

 

With a long experience with hangar queens, my frame of mind is that once a lead acid battery goes completely dead, it's never the same again. Once they go dead, I'll of course re-charge, but I start thinking of replacing it with a new battery. I keep a CTEK charger on all my cars that aren't driving often. The CTEK functions both as a trickle charger/maintainer and will also has a mild capability to charge batteries.

NAPA Legend batteries, Group 34, have both traditional posts AND side terminals. Perfect for modern logic circuit accessories that require a direct connection to the battery to avoid alternator noise. For instance, Vintage Air, Aeromotive Fuel Pump Speed Controllers, fuel injection ECMs.

Also, I've read that the AGM batteries and the gel electrolyte lead batteries can be damaged by overcharging or discharging below 50% of capacity. A wet lead acid batter can be discharged down to ~20%. Looks like the tradition wet cell lead acid batteries are more robust and of course are less expensive. Just reciting what I've read about AGM and gel batts. The problem with traditional wet batteries is that they can sometimes ooze electrolyte around the terminals and make a mess.

 

Something else thats often overlooked is that many battery chargers are now designed to charge a battery and then turn off once it hits a full charge. Because of energy star requirements they most often do not turn themselves back on later to top off the battery after self discharge drags it down. They also are now designed to not "boil the battery" like the very old type chargers. Sometimes this type of "boiling" is beneficial to a degree for helping to de sulfate the plates but too much can damage it. sometimes a battery can be recovered with one of these old chargers when a "smart" charger wont.

Some like trickle/ maintainers do but not full on battery chargers. I see this misunderstanding a lot in the golf cart forums where people will connect the charger to their cart in the fall and find the batteries are dead in the spring even though they were left on the charger. As suggested earlier a TIMER does wonders here as it reactivated the charger periodically.

Most trickle /maintaining chargers are like 1.5-2amps and not enough to properly "charge" a discharged battery even after sitting for a week or more, only maintain its current state of charge.

The walmart 2019 battery in my 74 was completely dead this spring from a door accidently left open.. I charged it and even though my smart charger stated is was sulfated at first, its worked fine since and is still in the green zone on my load tester so YMMV. I agree killing a battery does effect its strength and lifespan but it doesnt always damage the battery to where it need to be replaced. The type of charger you use can help too. I just replaced the 2012 and 2014 dated lead acid batteries in my golf cart so I must be doing something right.(I did build a lithium battery pack to replace those though)

 

I just bought another Noco charger but this one has a higher amperage. The charging amps, whether it be 1A or 50A, will charge a good battery but it will take 100 hrs to fully charge a 100AHr battery at 1A charge rate or 2 hrs using a 50A charge rate on the same battery. I bought the Noco Genius 10 charger. Its a 10 amp charger but when the battery fully charges, it goes into maintain mode. Yes, its a smart charger. Don't buy anything else other than a smart charger. Trickle chargers vice battery charger/maintainer will provide a low amp charge until your battery is toast or you constantly check the charge state of the battery. The Noco charger is also a multi phase charger. Not only does it know when to stop charging i.e. maintain mode, it will desulphate and and destratify batteries. It does this by pulsating a higher charge voltage (15V?). It does lithium batteries also. I'm sure there are other chargers that do the same but I liked those extra features. My 2 cents.

 

I been using this old thing most my adult life, still works great and I think they still sell them…

 

Me too! Its an inexpensive tool that works really well.