When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
decided to get a new battery....old one came with the car...decided to buy an optima after reading threads about the best batteries....got an optima yellow top....although some threads said they fit right in, they don't on my 85..had to modifiy the bottom of the case a bit to make it fit....the case covering the top terminals won't fit under the cruise bracket.., so you have to cut the terminals down.....
just want to say....WHAT A Pain taking out the battery!!!!...hopefully, for what I paid for an optima, won't have to do it again for awhile...
I thought the Yellow's were Deep Charge batteries i.e. used for trolling motors etc. I have had many of the red tops "have one in my 92" and they are great batteries. The key to making them last is proper charging. They require a slower trickle type charge and a regular charger for wetcell's will burn them up quickly. The military uses Optima's on most all none vehicle type applications.
Actually the U.S. Army did use some Optima batteries for Generator Sets (5KW and 10KW Onans IIRC). They also used some of the bigger 31A (yellow tops) not sure in what, but that size generally fits construction type equipment. As far as trucks, last I knew the Hawker Gel cell was the hot ticket (but it's been a few years).
I've had a few Optimas, but the general consensus (and I'd sadly agree) is Optima quality is not what it once was. Hopefully you got a good one. The off-road community (Jeepers) has forsaken Optima for the Diehard Platinum (or Gold) line. I have a DH Gold in my Vette now. And they fit without all the "adjustments"
Optima never offered a group 75 battery and everyone made due with modifications of the 78/34 and used that BUT I've seen some Optima applications for a 75/25 which should be a good fit for the C4. Never tried one and I'm not an Optima buyer but if a person was shopping it might be interesting to try a 75/25 for fit.
Optima never offered a group 75 battery and everyone made due with modifications of the 78/34 and used that BUT I've seen some Optima applications for a 75/25 which should be a good fit for the C4. Never tried one and I'm not an Optima buyer but if a person was shopping it might be interesting to try a 75/25 for fit.
OP - what did you buy?
78/34 based on forum threads.....dealer said he had red tops/ and some without top posts....but I took the 78/34. had to put a rubber pad at the bottom on one end...the new hold down they sent works great but it sits a bit too high to get the cover they make to cover the top posts.
it was too hot, too far to take it back....I just made it fit....I have a chrome cover which after I allow for the posts, will cover it nicely
I thought the Yellow's were Deep Charge batteries i.e. used for trolling motors etc. I have had many of the red tops "have one in my 92" and they are great batteries. The key to making them last is proper charging. They require a slower trickle type charge and a regular charger for wetcell's will burn them up quickly. The military uses Optima's on most all none vehicle type applications.
My alternator doesn't do "trickle" charge when the battery is low. AGM's are great if you need to mount them in some weird location but I'm not sure that they are all that. I had one in the 92 vette for years with no problems. At work, the mechanics are throwing them away left and right. They are not holding up for some reason.
Last edited by ANTI VENOM; Jul 1, 2014 at 04:42 PM.
Well any battery that is abused will have problems eventually...If you are buying an Optima so you can beat the crap out of it you will want to reconsider what you're doing. I see a lot of the AGM batteries out in many different applications now and they do just fine but they are still a battery...and degrade just like other batteries. Just my .02
yeah, I had a red-top that started out great and slowly petered out to the point of barely able to supply enough voltage to crank the starter for more than 5 seconds...
When tested...they came back and said it was full of dead cells. The alt was tested, and cables, all OK. A guy at the store admitted later that they had bunches of red-tops coming back...something about a bad batch. I opted out of the Optima swap and went with a top shelf 7 yr battery of typical design. It was disappointing to have a $200 battery go bad in less than 1 year.
I have a yellow top optima in my vette, they can take a beating repeated deep discharges they bounce right back quickly.
I did have my car sitting for a couple of weeks last year and totally flattened the optima after the antenna motor kept tripping the overload repeatedly (now that would kill a normal lead acid battery or it will never be the same). A normal charger will not charge a battery under 10.5 volts, you have to use a optima compatible charger OR get the battery out of another car. Connect them with jumper leads so the normal type battery charger can charge the optima, it needs higher than 10.5 volts to restore the optima battery to full charge.
That may be the reason they got a bad name, they think a perfectly good optima is dead will not charge and throw it away.
I have mine now for 3 years at least and it has been great no problems with it, you can leave the car sitting for months and it will suffer no side effects.
I used Optima red-tops in my Jeeps for years, and blue-tops in my boat.
When the blue-tops failed (finally) after 9 years, I switched to Lifeline AGM's.
I've had a few Optimas, but the general consensus (and I'd sadly agree) is Optima quality is not what it once was. Hopefully you got a good one. The off-road community (Jeepers) has forsaken Optima for the Diehard Platinum (or Gold) line. I have a DH Gold in my Vette now. And they fit without all the "adjustments"
I had two Optima red tops die an early death and leave me stranded. I heard the quality went way down after Johnson Controls bought them.
I have a Die Hard Platinum in my car. It is made by Odyssey (same chemistry as Optima in a different package). They claim the power density is higher because they don't have the air gaps between the cells.
decided to get a new battery....old one came with the car...decided to buy an optima after reading threads about the best batteries....got an optima yellow top....although some threads said they fit right in, they don't on my 85..had to modifiy the bottom of the case a bit to make it fit....the case covering the top terminals won't fit under the cruise bracket.., so you have to cut the terminals down.....
just want to say....WHAT A Pain taking out the battery!!!!
Sounds like you did it the hard way instead of taking off the vent panel.
Sounds like you did it the hard way instead of taking off the vent panel.
you got that right....didn't think I'd need the fsm to take a battery out....
took the cruise off/ cruise bracket off....loosed the top of that strut and then realized it would be way difficult to remove the bottom bolts on the strut. and that would be stupid just to take a battery out...went to the fsm.....a big help....live and learn..
decided to get a new battery....old one came with the car...decided to buy an optima after reading threads about the best batteries....got an optima yellow top....although some threads said they fit right in, they don't on my 85..had to modifiy the bottom of the case a bit to make it fit....the case covering the top terminals won't fit under the cruise bracket.., so you have to cut the terminals down.....
just want to say....WHAT A Pain taking out the battery!!!!...hopefully, for what I paid for an optima, won't have to do it again for awhile...
Playsdixie,
I have to admit I went for the Optima (red) for my C5. It lasted 34 months which was within the warranty and it was replaced with a new one. That lasted approx. 1 year. The issue with the Optima's is that the warranty for replacement is 3 years and that's it. There is no prorate after the three years. Also, what is interesting in my case is that Optima honors the 3 yr warranty by replacing the defective battery with another new on. You would think the new one would last three years also, when it doesn't you are out of luck. So how good are they for the money? I decided to replace the second Optima with an O'Reilly 5 year (3 Yr. replacement). I guess, after the experience with the Optima and the much higher cost I didn't see the benefit. My C5 runs fine with the O'Reilly and it has a five year warranty with Prorate after 3 years. I don't think the Optima's are really any better for what they cost.
hopefully mine will last a few years...the heat in florida is tough on batteries and don't have a lot of expectations... guess I should have looked a little deeper into batteries on the forum...initial thread searches had a lot of optima admirers so that's the way I went....probably should have researchec a little deeper....
This thread about Optima bats is scaring me. I just put a new red-top in my '88 Fbody. But my C4 got a 6-year AC delco. It has 30 month maint-free, which means they will replace it for free, then after that pro-rate. Most of my AC delco bats have lasted well past 6 years. As for the C4, Optima doesnt even list one, since there are fitament issues. And I wasnt hacking up anything just to make it fit.
I have always wanted to try an Optima. Mainly for power and reserve capability. Camaro has a few extra electrical loads installed......at least i should be good to go for 3 years.
I personally have had the better part of a dozen of them in everything from a plow truck to a street strip car and everything in between. I have never had an issue with them and most of them have gone to the 7-10 year service mark. I don't think that I've had one give up the ghost before 6 years. Just my .02
I personally have had the better part of a dozen of them in everything from a plow truck to a street strip car and everything in between. I have never had an issue with them and most of them have gone to the 7-10 year service mark. I don't think that I've had one give up the ghost before 6 years. Just my .02
On an 86, 75/35 fits perfectly after trimming the little ribs in the bottom of the battery tray sides. Front to back and up and down no problem with the top terminals. I believe the 75/25 is the same as well.
My last red top lasted 8 years and is still in service since I just donated it to a friend for shop use,