Problems with 6V Optima battery

[COE Dan]

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?

[F.M.G.]

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

[52merc]

i aree

[BUBBAS IGNITION]

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....

[BUBBAS IGNITION]

Here is one of the many google sites on charging a Optima. This method has worked for me a few times ..


http://www.ehow.com/how_5522442_char...batteries.html

[BrianCT]

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Originally Posted by BUBBAS IGNITION

Here is one of the many google sites on charging a Optima. This method has worked for me a few times ..

http://www.ehow.com/how_5522442_char...batteries.html

That is very interesting. I can't count the number of times in the past that I have seen warnings about not applying too many amps to the Optima.
Now I wont worry about my Ford showing 20 amps charge until the Optima comes up to full capacity.

[Frank The Plumber]

This seems like a really dangerous thing to do to charge a car battery. Is this on the outside of the battery anywhere? Geez.

[Bill Steiner]

I have never had any problem with 6V Optima batt. I have never charged it that way. Bill

[COE Dan]

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/produ...t/charging.php

Thanks for all the posts...

[oldredford]

Do you have 6 volt battery cable installed?

[Russ/40]

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.

[COE Dan]

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...

[Richard in Florida]

Originally Posted by COE Dan

The battery is constantly on a battery maintainer and I disconnect the battery from the car whenever it's on the charger/maintainer.

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/batter...u-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.

[FlatheadTed]

A old Flathead Ford benefits from good large cables ,Like welding cable as thick as your thumb.

[jbrittonjr]

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!

[COE Dan]

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.

[37 Coupe]

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.

[richard crow]

the one in my 35 ford is 15 years old no proulbem i use a batt. tender

[charles in east texas]

The new optima 6vs are a bit pricey at $189.95 plus tax. I have had two for about 7 years.

[ford38v8]

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?