cold cranking amps for one. Battery life for another. Gel celled batteries hold a great deal more power, plus they are safer. I have one in my 1958 that I only run about twice a month, i never have to tender it and its been in the car for over 5 years still running strong.

i've had my red top for over three years with multiple de-floodings..
yes im a flooder, anyway have not had a problem with it. but as stated they were sold and new company might be using a cheaper material for new batteries

yes optima was sold, BUT the guy started up another company so you can still get the original product. try orbital i believe.

Deep cycle batteries are hard on an alternator, but can be drained totally, and recharge just fine. Not all Optima batteries are deep cycle. Remember not to use a regular charger on a glass mat battery

I am mulling over the idea of upgrading my battery too. I see that group 35 is a fit, but I too also saw a 34r that looks very tempting given the "more power" in the cca dept.


As of today, I see that Optima has a red top 34r so the posts look right (pos and neg).

I am going to ask my Sears friend about their Platinum series. If they do have a 34r, then I might just try this option with a chance to return if I can not get it to fit.

I see that Sears has a four year free replacement too. Rather than ordering one online and dealing with warranty issues later....I think the Sears one might be a better option plus the ability to get the 34 r series in as a try first.

Any thoughts on this? Has anyone else tried this?

Thx
Rick


Ps just to had I just saw another post about a 34r optima being added with some work to the casing. I guess I will see if Sears carries a 34r and update my results.

Do not drain a deep cycle battery completely,20% remaining is the min: any more and the life of the battery will diminish. Most deep cycle work from full - 50%.

I've run deep cycle batteries totaly dead in my camper and they recharged just fine. I have never used a deep cycle battery in any car I've ouned, so the 50% rule is probally a good one. My point was to Optima (glass material) users was to know how to charge it, and to deep cycle users to be prepared to replace your alternator soon!

For thoes looking for a replacement, as I stated on pg. 2 look for a 124R series battery. 700CCA is enough unless u live at the north pole. It fits just like the one that came out. It is an odd series number, so the guy behind the counter might say it doesent exist, but I have one, and it works great!

Got an ACDelco in my eight still strong at 5 years.

On a somewhat related note:

Is there anything wrong with having the battery exposed in the engine bay? I recently popped my hood to check something out and noticed that the cover for the battery was loose; it was only being held on by the shape of the battery. Moments later I saw that somehow, the cover had literally cracked in half, so I took it off.

Now, I know there's nothing wrong with running without an engine cover (It may even be better for ventilation!), but I don't see too many people with their battery exposed. Any advice? Does it not matter?

I did see on another post that a member did in fact install a 34r. His was a Optima Red Top. I did see on Odessy's website that a 34r does exists. Now I just need to check if Sears carries it in a 34r also. Otherwise I will just install the 35 and be done.

Rick


I did look at the 124r that is also born with pretty good specs! I can get that in a wet cell, but as I am upgrading to relieve myself of the acid issues and if I do have a choice of going to a 35 with an option to the 34r, welllllll that 34r will get the job done and then some :).

Well when AMP hours dwindle, it is due to the electrolyte neutralizing over time, which in-turn increases the internal resistance in the battery and drops the voltage at the electrodes.

So, voltage does drop when battery runs out and can be used as a measure for battery life.

V(at electrodes) = V(Rated) - V(Internal resistance)
V(Internal Resistance) = I * R(Internal resistance)

As I said earlier, R(Internal resistance) goes up with discharge, hence V(Internal resistance) rises in a linear fashion, which in turn reduces the Voltage you get at the electrodes.

Potential difference is the force that pushes current out of the battery, and if it drops at electrodes, it will not push enough current to crack the starter motor.
So, yes voltage measured at electrodes is an accurate representation.

ok but whats I :P

i got mine from pepboys. but its a good thing that i read this thread. next time ima get optima! thanks!

ive got a duralast gold series in mine, been going strong in the completely screwed up texas panhandle climate for 3 years now, would have to look at battery but i think its 700 cca and 51ah and 100 reserve minutes which is pretty good for the smaller battery sizes

As an ol' EE myself I'm not arguing the equations with you, I was prior just pointing out that you can still have ~12 volts but low capacity, and it's the cranking amps that are most important (esp. cold cranking to overcome starter 'locked rotor').

Yes Huey, depending on the current I being drawn by the Galvanometer and the car itself, it might be 10-11 Volts for a discharged battery.

It mostly depends on the current drawn. But internal resistance is a killer, cant imagine how this is prevails even in the newer carbon nanotube batteries. I guess resistance is nature's way of telling us that we cant surpass a few limits.

Nice to meet a fellow engi. Cheers!

Right on Huey!!


Star Date Captain log: Sept 20, 2010.....as of this time Sears has an online sale for the Platinum Battery. You can order online and then pick up at the store.
An AGM Battery and FOUR years free replacement pretty much a $40 premium over a regular battery with an additional year warranty free replacement does it for me!

I'm also looking to buy a Battery Tender Plus unit. Nice charger for the AGM batteries and has a great warranty 10 years!!!

Thoughts?

Rick

^ I keep a Battery Tender (and rodent sonic deterrent) on my hybernating '8 all Winter. A great investment.

If you understand and respect the value of Amperage and Torque, life as you know it will be good!

^ "Torque does the work, but horsepower gets the credit."

-or- Amperage does the work, but voltage gets the credit. ;)

But there won't be any current without potential difference :p

^ When powerwashing the deck I'm availed of high potential difference (water pressure) and low capacity (volume), but when in the shower I like relatively low potential difference and high capacity - just like my '8. ;)

Volta was always a Prima Donna. :lol2:

I'm having the same problem as well. Bought it new from Amazon in Jan of 2009 and my Red Top is dead.