Optima battery will only chug to 50%

[Don]

Optima red top 6 volt will only charge to a little over 50% ,then charger shuts down,l just use it in shop for engine stand,trickle charge it when I think about it,,never leave it more than a day,,probally 3 or 4 yrs old
Any ideas how to bring it to full chug???

[tubman]

I am assuming you mean "bring it to full charge".

How are you measuring the batteries state of charge? Since it's an Optima, you can't stick a hygrometer in it. Are you measuring the voltage with a good meter, or just relying on the meter on the charger? Does the battery function well? Maybe there is no problem if it does what it should. I am on my third Optima, and they all went well over 10 years, so yours should still be good.

[Kube]

Originally Posted by tubman

I am assuming you mean "bring it to full charge".

How are you measuring the batteries state of charge? Since it's an Optima, you can't stick a hygrometer in it. Are you measuring the voltage with a good meter, or just relying on the meter on the charger? Does the battery function well? Maybe there is no problem if it does what it should. I am on my third Optima, and they all went well over 10 years, so yours should still be good.

I've had similar experience... most go ten years, one is at fourteen.
I do know charging takes the lifespan down. That's clearly noted in the instructions.

[WABOOM]

Use a manual charger at 2 amps to get it up 6.5 volts. Then discharge down to 6.2 volts using headlights and then charge it back to 6.3-6.4v

[RKS.PA]

Hi, Don,


As tubman said above, don't rely on your charger. Disconnect charger and measure voltage with your meter. Betting your Optima is still good!!....they are an amazing battery!!

[philipswanson]

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It's probably fine. Is it faltering under load? They have different charging characteristics. What kind of charger are you using? Does it have a switch for AGM batteries?

[gnolnor]

Don, Go to this web site and follow the instructions. It will charge the
Red Top 6V to 100%. Web site: thebatterybase.com.au

If the car it is installed in has Vido electronic guages, there is a constant
drain on the optima battery. I installed a battery cut off switch and use a trickle charger (6V) to keep at 100% charge. Once I see the green light on the trickle charger, I disconnect so I do not cook the battery. Gnolnor

[Krylon32]

I bought one of the small Optima chargers and have used it to breath new life into several Optima's. I just checked the 10 year old Optima in my delivery and it was still at 75%, didn't take long to bring it to 100%. Don't know if it'll last under everyday use. I'll probably replace it as I have the car sold and wouldn't want it to fail for the new owner?

[tubman]

When I go to Florida for 6 months in the winter, I hook battery maintainers to all of my vehicles. I then run extension cords from each tender into a power strip plugged into a manual timer in the wall outlet. I have found that powering the maintainers on for just 15 minutes a day provides enough energy to keep them at full charge without risking overcharging the batteries. These timers are available just about any where and they are cheap insurance against overcharging.

[Don]

Battery charger is a scheaur(spelling) that has a percentage meter also has settings for agm settings,
I also have optimum batteries in my roadster and model A ,at least 10 years on both and very little charging with tenders,really good service...
Battery in question reads 6. volts, but won’t last very long on running engine on engine stand,voltage to coil drops to 1 volt in a short time,,,,changed 3 carb,and coil befor I figured out problem of low volts,,,
I’ll try to discharge completely and try and bring it back up slowly,,

[supereal]

Glass mat batteries such as Optima are tricky to charge. Some chargers have a separate adjustment or that purpose. Charging at a too high rate can do damage to the battery. You may find the instructions by Googling "Optima"..

[Paul Bennett]

You need a Fluke Chugmeter.

I also have an optima which I charge every 12-24 months. I also have a great charger which handles that condition and goes into a 'repair' mode giving the battery periodic high current blasts to gradually bring it to 100%, mine starting from 4v up to the proper 6.4v.

$37 at Amazon "GOOLOO 6V/12V Smart Battery Charger and Maintainer 6-Amp Full Automatic 6-Stages Trickle Charging"

[Don]

Thanks for info Paul,think I’ll parallel a 6 volt optima with the bad one and try charging to see if that works,if not might go for the charger you mention,sure cheaper that a new battery at $185,,

[Paul Bennett]

Don, I also keep a 6v and a 12v motorcycle battery on the bench for checking things. They are quite cheap.