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.

Optima Yellowtop ftw.

Bumping this old thread because the more I read about batteries the more confused I get. Is the battery above a drop in replacement? On the Odyssey site it looks like it's listed as a motorcycle battery. The PC1200 looks OK, but I have no idea. I can't tell what sizes they are, the specs don't show it (?).

I was going to go with the Sears Die Hard Platinum P-5 (OEM'd by Odyssey), until I saw that it is 50lbs. I don't need a tiny racing battery, but I don't want to add that mother either. Don't they have a normal 35 series battery?

I used a PC680 in an e36 BMW 318is. They lasted about 2.5 years. Very small and lightweight.

Also, Amazon made good on the Red Top I complained about earlier in this thread.

Rather than start a new thread, I am going to piggy-back this one.....

My RX8 is a 2007, the battery in it is the the original one that it rolled off the assembly line with. Thus making it 5yrs. old +/-. The car cranks perfect. However, I know from experience, that a battery can crank perfect one day, and the next day when it decides it's had enough, not crank at all.

I am thinking that maybe I should be proactive and replace it. Here is where I am looking for opinions... I will be storing the car for the winter from about the 3rd week in Oct. to about mid-April. I will store it with a battery tender on the battery. Would it make sense to install the new battery before I put it away, or store it with the original battery that is now in the car and install the new battery in the spring? Thoughts?

Also, out of curiosity, does anyone know who makes Mazda's OEM batterys?

New battery can wait until spring. IMO.

+1 on that ^

Panasonic

i have a 04 with an original battery and its still going good

my oem battery lasted 13years in my audi.

My OEM RX-8 battery (2009 RX-8) died late last year. I suspect the garaging of the car in winter had something to do with that, but it's been my experience with all of my Fords that the OEM batteries last just about long enough to make it past the bumper-to-bumper warranty and then die. I usually replace them proactively now after I find out the design lifespan of the battery (3-year, 5-year, etc.).

I definitely agree that I would wait until spring to buy a new one.

Useful resurrection...kudos for searching.

When my OEM battery died (or was weakening) at 5 years, I just let the dealer put in a new OEM. $140, which is about $40 more than I could have done at Advance Auto. But I didn't get my hands dirty or strain my back, and the dealer took care of resetting whatever needs to be reset after a battery R&R. And it was cheaper than a fancy battery like an Optima.

Am I just getting lazy? :)

Ken

Red tops are good no doubt. I am currently on my second o e m battery. I think I paid $80.00 for it a year or so ago. I love searching the post , there is a wealth of information here. You just have to sift for the kief on that, but there are also a lot of mechanics etc here, racing people, very cool place to search.

I have a 2004 4 speed automatic velocity red. 78,000 miles on it. Great ca if you take the time to love working on it and discovering a new trick or a free mod like the throttle body by pass, cool stuff.

Anyone tried or looked at the Bosch S5 098? Looks like same specs and size as red top.
I'm considering it, will post an update if I take the plunge

Red Top all the way..better cranking than the Yellow. Only issue I had when I bought mine was that I needed to order it with reverse polarity, so make sure your new purchased battery has the positive post as shown in the first picture below, otherwise you will have issues connecting the positive terminal.

I bought a Red Top for $140.00 bucks through advanced auto parts about two years ago. They had some sort of deal on batteries and I saved quite a bit of money. Plus I think Advanced Auto parts will give you a free replacement if it goes out within 3 years...

I use this bad larry :) DieHard Platinum Battery : Buy High-Performance Battery at Sears

900+ CCA

Think turns over like a champ cold, hot, whatever lol.

Albeit it wont fit in the OEM spot ;p

Couldn't find a Bosch S5 with he right dimensions and the S4 doesn't look great specs wise, so I've gone with the crowd and ordered a red top! 35R right?!

Define the word "best" as it is application specific.

Race?
Audio?
Severe cold climate?
OEM application?
Relocation?

All these application require different types and rated batteries.

IMO Optima batteries are crap for all applications, but the yellow is better than the red as it is a deep cycle battery, but again that all depends on your application. I wouldn't waste the money on them, it's all hype.

Who are you replying to? The threat title, it was started in 2008.

I'm adding information to a thread that has recently become more active, thusly adding to the topic at hand that naming one battery the best is an ignorant approach to any mod no matter how small.

Apologies for contributing

FYI, my 925MJT is still doing well after almost 3 years.

Isn't there a consideration on how high in cranking amps you can or should go with out effect on the starter?.

This is where it gets tricky for us on the other side of the world. A lot of the names are either rare or non existent here. Non the less I have taken a note of them as it is just the beginning of winter here.
In my experience that is when my batteries seem to fail. Nights go to 0C maybe once or twice, and up to 14C during the day so it's not too bad. I'm really just pre informing myself so that I can at least have some basic knowledge if I have to buy a new one.
I may not be technically minded but threads like this do help.

I have tried a few over the years - went with smaller battery (to save weight) for a while - mistake ! I'm afraid these cars need the best cca battery you can ft into the box .

Amps are drawn as needed so you dont need to worry about that. You could have a 10,000 CCA battery, but if the starter only can take 100 amps .. it only uses 100A.

This is the opposite of voltage.

Hope that helps.

Thx. Good to know.