Strange Battery problem. Optima

F

frederic

Senior Member
Just went out today and tried to charge my Optima 6 volt battery as it would not engage my starter. (starter would just spin and not engage) Hooked charger up pos to pos and neg to neg. Battery charger jumped all the way to 0 then clicked back. it kept doing this so I figured something was wrong. Got out my electric current tool out and set to DC-10. put pos to pos and neg to neg. The needle registered in the negative. Placed neg pointer on pos terminal and pos pointer on neg terminal and got positive 6 volt reading. Checked this several times to make sure i was touching correct pointers on correct battery terminals. Thought my tool was shot so tried it on several other Optima 6 volt batteries I have and everything worked correctly. What is happening ?? Can a battery change polarity?? now this battery was in the car and worked the lights and gauges. I have not hooked up the Generator as of yet but was only trying to check if Starter would turn over. Will the starter run backwards if polarity is reversed ?? Can a new Regulator cause any problems as I have one installed but have not as of yet hooked it up to Generator. I think this battery was in this car before i re wired entire car or at least in one of my old fords. Has anyone ever gotten a battery with the terminals mismarked ?? just strange !!!!

Thanks for listening and any ideas

Frederic
 
frederic,

A couple of things to think about:

1) Will a good (different) 6V battery cause the starter to spin and also engage the starter? If not, bad starter drive...

2) I've got a couple Optimas. Here's my take on charging. They don't act like a regular lead acid. Rarely will they register zero amps when fully charged. Normally, they will draw some current. But they shouldn't start at 0A and climb...I'd suspect a bad battery.

3) You said you hooked up an 'electric current tool'. Does this measure current or voltage? If voltage, you should get about 6.3V across a good Optima. If current, all you will register is a deflection that indicates current flow. This will reverse if you swap the terminals.

4) It's possible for a battery to internally short, have a failed cell (read lower voltage)...each cell produces about 2.2V. Due to the chemistry, it is not really possible for a battery to swap polarity. Hooking it up backwards or charging it backwards will just destroy it.

5) Starters don't care about polarity. They run the same direction regardless of polarity. This is why you can swap from positive ground to negative ground and not change out your starter motor. It has to do with the way the motor is wound internally. My 47 COE has be converted to 12V negative ground like many other vehicles. The stock starter spins the same direction but twice as fast (double the voltage).

6) The regulator won't change a battery's polarity but can destroy one if improperly polarized. More than likely a regulator will cause either overcharging (too much voltage) or undercharging (too little voltage).

7) I've never heard of mismarked terminals although I have heard of Optimas with incomplete connections inside (battery became an open circuit with zero voltage). Doesn't mean it couldn't happen I suppose.

In short (no pun intended), try a different known-to-be-good battery if you still have same problem, it might be the starter.

COE Dan
 
Frederic, Dan has given you excellent information. The practical application of Dan's advice would include a review of your understanding that an early Ford's braided ground strap is Positive, and the insulated conductor is Negative. Of course this is counter intuitive, and easy to confuse!
 
Thanks Dan. yes it was a voltage checker I used to test bat. I was going to today take another bat. and try it in place. But this ODD bat. still is backwards and when I check it with voltage meter neg to pos, pos to neg , it resisters a correct 6.3 V. Any way will report this eve on results.

thanks again

Frederic
 
Optima batteries are full of magic....now ya see 'em ...now ya don't....just like that. Been there ...done that. I tried all the special charging methods, ad nauseum,.
4 optimas later ( 2-12V & 2-6V) Now I have Sears batteries and no problems (3+yrs, 1 battery is 6+ yrs old)
 
update on Optima batt. This for sure has the battery posts on opposite sides. I put in two others, once hooked up they functioned as they should. I put the ODD batt back in backwards (pos to neg and neg to pos) and it works fine. So now my positive grounded car has a backwards marked Optima battery installed. I will label it with some sort of mark so as to not forget when charging or during maintaining peroids. I have also never heard of a LOW charged battery being able to change polarity when being charged.

thanks for all the input. This is a real brain teaser or perhaps the poles have shifted and I dont know it yet LOL

Frederic
 
My 2 cents, from an molecular point of view on how a battery works is that some elements always have -'s and other elements always have +'s. When you put the two together the chemical reaction makes one post always negative and the other always positive. I would think it is difficult to change the molecular workings of nature. I do not know the history of the battery. But it appears to me to be manufacturer labeled wrong.
 
It is possible to charge a dead battery reverse polarity.

It is not possible to charge a dead optima with a lot of battery chargers. Must be a newer charger, and not all newer ones will do it.
 
Starter spins and does not engage is probably a bad starter drive and the battery may be ok. It could also be worn teeth on the flywheel. Moving the motor a 1/4 turn may let it engage. I am guessing the battery is ok.
 
Junknshit, I'm not sure I understand your statement regarding old chargers. All you need is a 6v 2 amp automatic shutoff charrger. Mine is an old Monkey Ward 6/12 unit and works just fine.

A note about charging a completely dead Optima: The charger will not recognize a battery if there isn't enough juice to complete a circuit. To make it work, you must hook up a second battery parrallel to begin the charge.
 
If the battery were mine, I'd hook up a 12 volt bulb and leave it on till the battery is completely dead. Then you can recharge and correct the polarity.
As to the statement that old chargers will not recognize a dead battery, that is incorrect. It is the newer chargers with the more sophisticated circuitry that will not work with a dead battery.
Also, be aware a battery that reads full voltage is not necessarily a good battery. A battery can hold a full surface charge, and yet, not be able to deliver enough current to spin your starter. The true test of a batteries condition is a load test to see if it maintains voltage at high current draws.
 
If the starter spins and does not engage the motor, the starter drive is at fault. Pull the starter and clean the drive don't lubricate unless with a very small bit of dry lube such as graphite or LPS #1
 
These batteries seem to just go bad, have a 12 volt used the car for several days, go out the next day nothing, tryed to charge nothing, think it now has a bad cell! Put in another battery started right up. Don't think I will get another one.
 
Optima's have a connection errosion problem where the top of the cells connect to the terminals. They made the case a little higher to try to over come the problem but most still fail in time. This is the reason they changed the warrantee to a full replacement for I believe 3 years from a longer prorated. They are still the best batteries for the old Fords and eliminate corrosion in the box and surrounding areas. I cut 2 that failed apart and could see the problem. G.M.
 
Thanks guys for all your thoughts. I really think i let this batt run fully discharged as i had it hooked up to several clocks I am restoring. I then think I hooked up the CHARGER on the wrong terminals and it charged backwards. I KNOW when new it was installed with correct posts to operate the starter. In any event is is working well and starts the car fine.
 
On a battery that is charged backwards you can hook a light bulb to it and run it all the way down until the light go's out then charge it to the right polarity. G.M. I see looking back that Russ already suggested this method.
 
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