Problems with 6V Optima battery

COE Dan

COE Dan

Senior Member
I have a 6V Optima battery in my 1939 Ford. I've been having electrical issues since I got the car this last July. I did not install the battery and I have no idea how old it is. Here's my problem:

I only get a few trys to turn over the engine upon starting out of the battery before it is depleted to the point it won't turn the engine over. I thought this was normal for a 6V system...but I'm not sure. I've cleaned all the contacts on the engine (coil, condenser, starter solenoid, etc), checked the ground, etc.

The battery is constantly on a battery maintainer and I disconnect the battery from the car whenever it's on the charger/maintainer. Last week it was pretty cold here (35 degrees) and I got 1-2 revolutions before I ran out of juice. Today it was 65 degrees and I got the same couple of cranks and nothing more.

Now I'm suspecting the battery is internally failing. It holds a charge of about 6.25 V when on the maintainer. After the attempted cranking, it measures about 6.1 V.

My questions are:

1) does this sound like a battery problem?
2) is it possible it's a starter issue?
3) if I replace the battery, what size goes in a 1939...I think it should be a group 2 but I'm not sure?
 
Sounds like you need to check the voltage while you are cranking your car, are take the battery to get load tested. Should drop to about 5 volts when it is cranking. I had this same thing happen and it was a bad Optima got a new one and it cranks like 12 volts. Mike
 
I would suggest two thoughts:

1=Take the battery soemwhere and have it checked

2=Google info on the optima battery and how to properly charge them. They dont like a slow charge and a battery maintainer makes them even worse. These new batterys have a memory and often will only output what they are input. The newer chargers are made to smack one of these really hard with some heavy current let off and hit it again. This usually fixes the battery....
 
Sorry, the 100 amp shock treatment does not pass the sanity check with me. I initially charged my Optima with a 15 amp charger and in 15 minutes it got hot and started to whistle (gases escaping from the vent). I'm not going to try the 100 amp trick...sounds like a good way to blow up a battery.

I did some Googling of my own and found that Optima has a website and the manufacturer recommends the following charging procedures for redtop 6V batteries:

Alternator:
6.9-7.5 V, no amp/time limit

Charger
6.9-7.5 V, 10 Amp limit
6-12 hours (approx)

For a rapid recharge:
7.8V max
no amp limit but battery must remain below 125 degrees F
Charge to 1 Amp draw on charger

For a float charge:
6.6-6.9 V
1 amp max
no time limit

Here's the website address:

http://www.optimabatteries.com/product_support/charging.php

Thanks for all the posts...
 
A good 6 volt optima would crank that thing for a hell of a long time. It's bad. Not a cable issue, because it poops out after awhile. Since it's on a maintainer it should be fully charged if the maintainer says "charged". I'm banking on the battery is old and bad.
 
The wiring is all original (ok not original) but original size. I'm going to check the starter wiring again and make sure I've got good connections there. That's the last item I will check...then I will have to assume it's a bad battery.

Thanks for the help...
 
COE Dan said:
The battery is constantly on a battery maintainer and I disconnect the battery from the car whenever it's on the charger/maintainer.
Click to expand...
At 6.25 volts, you're not really charging it at all. You need north of 7 volts to charge, and then 6.7 to float.

Optimas require (maybe the word is "prefer") a special charger/maintainer/conditioner that uses a different float voltage than the discount store specials. From my own personal experience I strongly recommend the BatteryMINDer by VDC Electronics. Look here...

http://www.batteryminders.com/batte...rger-Maintainer-Conditioner-Desu-p-16138.html

If the link doesn't work, then go to their site and search for #12106.

They're a bit pricey, but they're worth every penny. I had their six-volt unit with my six-volt Optima, and now I have one of their twelve-volt units.
 
My F-3 still has the 6 volt system.
If I didn't want to keep it original I would switch to a 12 volt system in a heartbeat.
That said, you might want to check the battery cables at their terminations. Contact areas between the battery cable ends and the starter lug or engine block should be bare, bright metal. I use petroleum jelly or dielectric grease to coat the contact areas in order to slow corrosion. In addition you might consider using "star" style lockwashers at the cable ends as they "bite" into the metal and help maintain a good connection.
Feel the battery cables after you've cranked the engine over. The cables should not be warm or hot. If they get hot check for corrosion or a failed crimp or solder connection.
Good luck!
 
Thanks, all. There's some good stuff to try.

I checked my battery maintainer and it only has a 6.3 V output when charging. The Optima battery appears to hold a high voltage state 6.25V even when the battery is discharged heavily. The float charger doesn't have enough voltage to reverse current flow into the battery...only enough to prevent it from further depleting. That may be part of my problem.
 
I know this has been awhile but did you ever get the 6 volt Optima charged or was the symptoms that of a bad Optima 6 volt that you replaced? Do you remember how old it was? Think my Optima is having same issues,I have always been pretty faithfull keeping a battery tender on it and driving it but have slipped up on both this past season. Think I have had it iabout 5 1/2 years. How many years have other Barners gotten out of them? Biggest reason I went with Optima was to eliminate corrosion on 37 firewall and the cranking power when it was healthy.
 
I have 10 year old Optima that has never been charged. What say you all on the best chance of waking up this sleeping beauty?
 
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