Red Top Optimas

[Medsker]

Each cell has a voltage rating. When a cell 'dies' it loses that voltage. Say each cell is good for 2v. If you have a fully charged 12v battery that is only 10v, then you know 1 cell is dead or shorted. They are all lined up in series, so if one dies, you lose voltage.

What if each cell is just down .333 volts...then it would still read 10 volts and it could be caused by a low charged battery or a build up of sulfur on all the plates that is not allowing the little electrons to smash into the complete plates making the full potential of the plates (this is all of course if I understand how a battery works which I may not, just trying to figure it all out).

Medsker

PS Not trying to be combatant, I really want to learn because I always thought there was no way to tell if a cell was bad except with a hydrometer test.

 

[waynehartwig]

What if each cell is just down .333 volts...then it would still read 10 volts and it could be caused by a low charged battery or a build up of sulfur on all the plates that is not allowing the little electrons to smash into the complete plates making the full potential of the plates (this is all of course if I understand how a battery works which I may not, just trying to figure it all out).

Medsker

PS Not trying to be combatant, I really want to learn because I always thought there was no way to tell if a cell was bad except with a hydrometer test.

A fully charged battery wouldn't be at 10v, unless there was a dead cell, though. All of the other 'problems' you mentioned are all why a battery won't hold a charge or runs dead quick. Typically dead cells are shorted, which takes them out completely and that's why you loose the 2.1 volts or whatever it is.

If the battery has a dead cell, but it's open, the battery won't take a charge at all and will not show any voltage. It's the same if the battery doesnt' have any water in it, or very low.. But we're just talking about dry cells here.

Also, in a dry cell battery, I don't think they can sulferize, as I believe the only time they can is if tainted water is used to fill the battery. There's definately not a hydrometer test available.

With a volt meter you can really figure out what is going on with a battery and alternator. But the bottom line is if the battery won't take a charge or hold a charge, it's bad and needs to be replaced. So saying a battery has a dead cell, may be their way of saying the battery is toast.

 

[88 Runner SAS]

I had my first red top for about 5 years and fried it due to over charge. I completely drained it twice in that five years, it would not charge at all with a regular charger, or jump starting and letting my runner charge it. I put a 2 amp motorcycle trickle charger on it and it came back to full capacity. Have one in each of my rigs now and will put a second in the back of the runner this winter.

 

[Medsker]

Also, in a dry cell battery, I don't think they can sulferize, as I believe the only time they can is if tainted water is used to fill the battery. There's definately not a hydrometer test available.

Optimas are actually AGM's not dry cell batteries but I figure you know that as it is common to call them that. Dry cell batteries are like regular batteries only they have a paste in them where as AGM's are absorbed glass mats. They have acid in them just like a regular battery but the acid is just soaked into a "fiberglass" mat that is sandwiched between the lead. On a regular battery sulfurization is caused mostly from age and leaving a battery discharged. As the battery sits discharged, the sulfur hardens on the plates leaving less space on the plates for electrons to run into thus leaving it with less power. On AGM I'm not sure if the same thing happens or not. On an AGM they can use a 99.9% pure lead as opposed to a regular lead battery which uses around 80% so I would assume they don't have as much of a problem with it but I have no expertise in this area.

With a volt meter you can really figure out what is going on with a battery and alternator. But the bottom line is if the battery won't take a charge or hold a charge, it's bad and needs to be replaced. So saying a battery has a dead cell, may be their way of saying the battery is toast.

So basically 20 years ago they tested mainly with hydrometers and really tested for "dead" cells and now the term is still used generically for any battery thats not functioning properly . That makes sense to me now.

 

[Brad J]

Seems they need to be charged in parallel with a standard battery... I didn't beleive it myself until I tried it... brought a psuedo-dead RedTop back to life.

Kurt, Thank you for the tip. I had written off my old Red Top after sitting for 2 years in my Scout w/o being started. I tried charging it several times w/o any success & put it on the shelf to take in as a Core for the next battery purchase. I charged it in parallel several weeks ago w/ a standard older battery & its back to life & can start even after sitting for a couple weeks

Thanks, Brad J