f85stealth Posted February 20, 2008 Author Share Posted February 20, 2008 Nick, this is f85stealth you're dealing with. f85, CzarDestructo is an electrical engineer. He knows what he is talking about. I am an electrical engineer graduating ITT Tech with my degree its nuthing special Link to comment Share on other sites More sharing options...
LuckyBob Posted February 20, 2008 Share Posted February 20, 2008 f85 - I think the thing that you're overlooking is that battery voltage versus percentage discharge isn't a linear function. From what I've seen, most every type of battery has an initial voltage drop which happens quite rapidly, and better batteries will maintain a higher voltage for longer after the initial drop. The below chart illustrates this: the black line is a Sanyo 1950FAUP NiMH battery (source). I'm sure it isn't exactly correct compared to any particular car battery, but the principle's the same. http://www.voltmagic.com/images/discharge_curve_5a.gif The testing procedure you've used above tests for the first ~1.6-3.2% voltage drop, which I would fully expect to happen quite quickly. A dead (10.5VDC) battery represents a 12.5-14% loss in voltage, which should occur after much more discharging. Hopefully the Optima - being the better battery - has a "flatter" curve after the initial discharge and holds onto its voltage for much longer than the stock battery. 10.5V might be way too low for your comfort for testing, but I suspect 11V would still start the car fine; testing's key. The more commonly accepted measurements for battery capacity are watt-hours and failing that Ampere-hours (definition), since they're both a measurement of potential energy over time. Voltage is definitely important (and watt-hours takes that into account), but past the initial drop a good battery should keep its voltage up for quite some time. For comparison, here's a lithium-ion battery pack (which looks better than it is since all lithium-ion batteries have onboard controllers, hence their price) http://www.powerstream.com/z/pst-mp500.gif And what looks like a lithium-ion cell (without a controller) http://www.ibt-power.com/Battery_packs/Li_Ion/Li_Ion_DiscGph.JPG ...No battery could run with an 80 amp load for 4 hours with no charging source... Biz77 meant that the test was done at 85 degrees Fahrenheit, with a 25 ampere continuous load. Since the Optima has a rated capacity of 48Ah (source), it should last for ~1.92hrs (48Ah/25A) under those conditions until dead. It has a stated reserve minute capacity (definition) of 98min, which should be enough to meet your goals provided you aren't drawing much more than 25A continuous. If you've got an ammeter and you're not drawing insane amounts of power, give it a shot at running it for around an hour and see if the car still starts fine. Link to comment Share on other sites More sharing options...
CzarDestructo Posted February 20, 2008 Share Posted February 20, 2008 Guys, just let him be and stop wasting your time. He makes up his own reality and believes what he wants. I just find it rather disheartening that he's actually an EE though. Link to comment Share on other sites More sharing options...
Mitch Posted February 20, 2008 Share Posted February 20, 2008 How do you confuse 80 degrees F. and 25 Amp load with 80 Amp load test? I have no vested interest and just wandered in here from New Posts and I got it...? If I'm going faster than you, Move Right. Link to comment Share on other sites More sharing options...
hassa Posted February 20, 2008 Share Posted February 20, 2008 I am an electrical engineer graduating ITT Tech with my degree its nuthing special LOL - did you get to keep your toolbox when you were done :lol:? This reference may be lost to anyone outside the NY/NJ area..... Sorry, not to hate, but ITT can hardly be called a "real" engineering college/university - it's more of a trade/technical school. However, I agree 100% with you in that a degree doesn't mean everything unless you live in a lab all day or are a college professor. Link to comment Share on other sites More sharing options...
biz77 Posted February 21, 2008 Share Posted February 21, 2008 How do you confuse 80 degrees F. and 25 Amp load with 80 Amp load test? I have no vested interest and just wandered in here from New Posts and I got it...? Look here: http://www.legacygt.com/forums/showthread.php?t=72662&highlight=brembo+prodrive and you will begin to understand the enigma that is f85stealth. Link to comment Share on other sites More sharing options...
a.spider Posted February 21, 2008 Share Posted February 21, 2008 I am an electrical engineer graduating ITT Tech with my degree its nuthing special Obvious BS, since ITT Tech does not even offer Electrical Engineering degrees. They do however offer Electrical Technician degrees. From their website: "This program can help graduates begin careers in a variety of entry-level positions in various fields involving electronics and computers. These may include, among others, such positions as technician, electronics technician, field service representative, salesperson and computer technician." There is a vast difference in the knowledge required for doing electronics design vs being an electronics technician. This is not a slam at technicians, I am merely pointing out that f85stealth is blowing smoke by making an appeal to an (imaginary) authority. Link to comment Share on other sites More sharing options...
tommypenguin Posted March 18, 2008 Share Posted March 18, 2008 I really wish all the trash talk would cease in this thread, I just wasted 10 minutes reading people's trash in search of my answers, if you don't have anything constructive to add keep it to yourself. I am in the position where I have been so close to buying an optiama yellow top so I can play my stereo with the car in the off position for no longer than an hour. When my OEM battery was new I could get up to 45 minutes with the car completely off running on battery power. Currently I have drained my battery so many times, I can get about 5 minutes running on battery power before it dies. I was hoping the optima yellow top was the answer to my prayers, but now I'm not so sure. f85 what is the longest you have run your optima yellow top on battery power only before it has died? Would you recommend it for the application I'm looking for? I used to run my car everyday on battery power on brakes at work while I would go out and play guitar hero. Now I have to start my car just to play one song because my battery is so close to dead. I hate starting my car just to let it idle, not good, so I'm looking for a fix asap. Any 'Useful' opinions on battery brands that would fit the bill for my application are welcome. I'm open to any battery, I just want to make sure I get the right one the first time. Link to comment Share on other sites More sharing options...
whobaru Posted March 18, 2008 Share Posted March 18, 2008 My experience: In my Acura, I installed a yellow top and could run two amps at 3/4 volume for an hour. Car fired right up. Link to comment Share on other sites More sharing options...
CzarDestructo Posted March 18, 2008 Share Posted March 18, 2008 I really wish all the trash talk would cease in this thread, I just wasted 10 minutes reading people's trash in search of my answers, if you don't have anything constructive to add keep it to yourself. Any 'Useful' opinions on battery brands that would fit the bill for my application are welcome. I'm open to any battery, I just want to make sure I get the right one the first time. If you had actually read the posts you would have read that what you desire is ampere-hours (aH), which represents the capacity of a battery. Brand preference is just that, preference. Check the raw numbers of what you're buying. However, you're from CO, so I would highly recommend a good combination of CCA and aH since it's a cold climate. Also don't make a habit of discharging your new battery beyond 75%, they don't like that (unless they're deep cell)! Link to comment Share on other sites More sharing options...
Prime Power Posted March 18, 2008 Share Posted March 18, 2008 This is from a member of another club I am in: I'm going to be Mr. Miser and say "DON'T BUY AN OPTIMA!!!!" http://www.chevyavalanchefanclub.com/cafcna/Smileys/cafcna/thumbdown.gif While I was in the auto parts industry I sold many and warrantied almost the same exact batteries with in a years time. Optimas quality well to poopoo about 5 years ago. All the batteries that were sold before about 2002ish were great, and I can emphasize that enough. I have one of the older red tops for like 8 years before it took a crap. If you are looking for more cranking amps or you have a stereo then you can series a couple of 6 volt batteries or there is a REALLY great battery on the market called ODYSSEY. they have some good options for the batteries and their CCA's are far superior to Optimas plus they last much longer. Exide also has a really good wet cell battery called the Nascar E108. It had a 40 month free replacement and a 108 pro-rated warranty. These batteries are designed for long periods of idle conditions with electronics on, they're targeting police cars and small fire vehicles because of the demands on the batteries when they are in use. Now I know that are may be quite a few of you that have some luck with you're newer Optimas but I've seen MANY frustrated costumers when it comes to these batteries. I would save yourself the headache and buy a really good wet cell or and Odyssey. Link to comment Share on other sites More sharing options...
tommypenguin Posted March 18, 2008 Share Posted March 18, 2008 If you had actually read the posts you would have read that what you desire is ampere-hours (aH), which represents the capacity of a battery. Brand preference is just that, preference. Check the raw numbers of what you're buying. However, you're from CO, so I would highly recommend a good combination of CCA and aH since it's a cold climate. Also don't make a habit of discharging your new battery beyond 75%, they don't like that (unless they're deep cell)! What is stock battery's ampere-hours (aH), and what is the yellow top's? I did read the thread and understand what I need, but no one has said which specific batteries will fit the bill I'm looking for. I could invest some time and search on google looking up several batteries, but I figured I would get the opinions of those with aftermarket batteries. from here first What can I say I'm in a lazy mood for once. If an instate battery ampere-hours (aH) is substantially higher than stock I might just be best off with that. Help me decide guys. I read earlier the yellow top has 650 CCA compared to stock 550CCA. Lets assume I will run the battery down 75% because of my habits. The yellow top will recharge better because it is deep cell? And it will have more ampere-hours (aH) than stock? If so, I will buy the yellowtop. I was hoping since f85 actually has it in his legacy I could get his opinion on how its worked for him... Link to comment Share on other sites More sharing options...
tommypenguin Posted March 18, 2008 Share Posted March 18, 2008 This is from a member of another club I am in: I'm going to be Mr. Miser and say "DON'T BUY AN OPTIMA!!!!" http://www.chevyavalanchefanclub.com/cafcna/Smileys/cafcna/thumbdown.gif While I was in the auto parts industry I sold many and warrantied almost the same exact batteries with in a years time. Optimas quality well to poopoo about 5 years ago. All the batteries that were sold before about 2002ish were great, and I can emphasize that enough. I have one of the older red tops for like 8 years before it took a crap. If you are looking for more cranking amps or you have a stereo then you can series a couple of 6 volt batteries or there is a REALLY great battery on the market called ODYSSEY. they have some good options for the batteries and their CCA's are far superior to Optimas plus they last much longer. Exide also has a really good wet cell battery called the Nascar E108. It had a 40 month free replacement and a 108 pro-rated warranty. These batteries are designed for long periods of idle conditions with electronics on, they're targeting police cars and small fire vehicles because of the demands on the batteries when they are in use. Now I know that are may be quite a few of you that have some luck with you're newer Optimas but I've seen MANY frustrated costumers when it comes to these batteries. I would save yourself the headache and buy a really good wet cell or and Odyssey. Where can I get an Odyssey battery? Link to comment Share on other sites More sharing options...
CzarDestructo Posted March 18, 2008 Share Posted March 18, 2008 What is stock battery's ampere-hours (aH), and what is the yellow top's? I did read the thread and understand what I need, but no one has said which specific batteries will fit the bill I'm looking for. I could invest some time and search on google looking up several batteries, but I figured I would get the opinions of those with aftermarket batteries. from here first What can I say I'm in a lazy mood for once. If an instate battery ampere-hours (aH) is substantially higher than stock I might just be best off with that. Help me decide guys. I read earlier the yellow top has 650 CCA compared to stock 550CCA. Lets assume I will run the battery down 75% because of my habits. The yellow top will recharge better because it is deep cell? And it will have more ampere-hours (aH) than stock? If so, I will buy the yellowtop. I was hoping since f85 actually has it in his legacy I could get his opinion on how its worked for him... I will be the first to say I'm completely ignorant when it comes to battery brands. I still use the stock battery because it suites my purposes fine (although its a little weak on cold mornings). Don't get stuck on a brand name preference, check out stats, prices, and warranties. Batteries are pretty simple devices, I wouldn't lose sleep over making a decision. When I briefly looked into yellow and red tops I realized there are many variations, all with different properties. It's a matter of finding the size that fits our Subaru (I'm sure this info is floating about the forums somewhere), and checking up on it's relevant numbers (CCA aH). I can't say with 100% certainty, but I'm rather sure any decent aftermarket battery will have more aH than the stock battery. I don't think the stock battery even has the aH stamped on it. Furthermore, your battery is old AND you've completely discharged it several times it sounds. Basically your battery is totally cooked which is why it doesn't hold a charge anymore. In regards to your discharging beyond 75%, this damages electrodes and severely handicaps the battery if its not a deep cell. Deep cells have beefier plating and electrodes to handle that kind of stress, as a result they're heavier and more expensive. I'm not sure you'll honestly need that though, and the yellow top isn't a deep cell (although I know Optima makes deep cells). I doubt an hour of loud music will ever kill a half decent aftermarket battery, my stock battery (although still only a few months old) can handle a 1500watt amp cranking a decent volume for well over an hour no problem. Please, don't listen to anything F85 says, it will only be a detriment to your ultimate decision. Everything he has done and said thus far has confirmed his complete incompetence. Sorry for the long ramble and I hope this aids your decision. Godspeed! Link to comment Share on other sites More sharing options...
Prime Power Posted March 19, 2008 Share Posted March 19, 2008 The yellow top is a deep cell. The red is the one that is not. Link to comment Share on other sites More sharing options...
tommypenguin Posted March 19, 2008 Share Posted March 19, 2008 After reading for a while I'm going to pick up an exide deep cycle battery tomorrow sounds like the best bang for the buck. Link to comment Share on other sites More sharing options...
whobaru Posted March 19, 2008 Share Posted March 19, 2008 Optimas quality well to poopoo about 5 years ago. All the batteries that were sold before about 2002ish were great, and I can emphasize that enough. If this is true, it would explain why my yellow-top experience was so great and I feel I must constantly defend them to other members that rant about their issues. I bought mine in 2001 and it is still going strong in my Acura I sold to my little brother. He's got a bigger system than I did and never has any problems. Link to comment Share on other sites More sharing options...
biz77 Posted March 19, 2008 Share Posted March 19, 2008 Where can I get an Odyssey battery? I see you've already found an alternate, but anybody looking for an Odyssey battery should look into the Die-Hard Platinum batteries. It is an Odyssey battery in a Die-Hard case and to top it off they are less expensive than the Odyssey branded variant. Warranty kicks a$$ too. Link to comment Share on other sites More sharing options...
tommypenguin Posted March 20, 2008 Share Posted March 20, 2008 Interstate Megatron for me... never let me down... ever. http://www.interstatebatteries.com/estore/search.asp?details=1&mscssid=V3DULR8THEF38J8URA520UARM0HP31H8&Ntt=MTP%2D35&N=0&Dx=mode+matchboolean&part_number=MTP%2D35&Nty=0&D=MTP%2D35&Nu=Part+Number&Ntx=mode+matchboolean&part_desc=Mega%2DTron+Plus+%2D+85+Months+%2D+640+CCA&Ns=product+Type%7C0%7C%7CRank%7C1&Ntk=SearchGroup&js=1 http://www.interstatebatteries.com/estore/zoom_image_pop_up.asp?Image_Name=ibs_MTP-35.jpg Manville Smith JL Audio, Inc. Change in plan guys, I went to go pick up the orbital deep cycle battery, but the terminals were located on the side of the battery closest to the bumper. My cables weren't quite long enough to reach, and then I got to thinking, 200+ is a lot to shell out on a battery. Instead, I'm going to go with mssmith's recommendation to get a interstate mtp-35 battery. For 90 bucks, seems like best way to go. For the money if it dies I could buy another battery and still come out ahead over the deep cycle. I will post my reviews on it in a couple months or so and let people know how its panned out for me. Link to comment Share on other sites More sharing options...
msmith Posted March 21, 2008 Share Posted March 21, 2008 You've chosen wisely, Grasshopper. Link to comment Share on other sites More sharing options...
Cossey Posted March 21, 2008 Share Posted March 21, 2008 I only read the first 20 or so posts, but CCA isn't the guy's real problem. It's the RESERVE CAPACITY. Reserve Capaciy- BCI defines it as "the number of minutes a new, fully-charged battery at 80ºF (27ºC) can be discharged at 25 amps and maintain a voltage equal to or higher than 1.75 volts per cell" (i.e., 10.5 volts for a 12-volt battery). This rating represents the time the battery will continue to operate essential accessories in the event of a charging system failure. At Advance, we do a TON of warranty claims for Optima batteries, yellow top specifically. Too many people don't understand that it's not a normal battery in terms of usage. It really should be taken care of. This is why the yellow tops only have a one year warranty, and not a 3 year like the red tops. Yellow tops can be great if taken care of, and used in a car that will actually use the deep cycling properties the battery was intended for. People bring them into Advance alllllllll of the time to get them warrantied because they won't start their car, and they leave with a new battery every single time. Our charger's only intended to make a battery work after charing it for a max of 55minutes. So someone brings in a drained yellow top, and when we put it on the charger, it pretty much says "there's no way I can charge this thing in 55minutes, it's a bad battery." So after that, I put it on a trickle charger over night, test it the next day and it's a good battery again. Next time you go to Advance Auto, ask if they have an Optima's in their used battery program. I know my store has about six. -Disgruntled Advance Auto employee lol Link to comment Share on other sites More sharing options...
whobaru Posted March 21, 2008 Share Posted March 21, 2008 That may be why my yellow-top worked so well. The only two times I completely killed it, I did an overnight trickle-charge and it came back 100%. That's why I like deep-cycle. Link to comment Share on other sites More sharing options...
coyote_5 Posted July 2, 2008 Share Posted July 2, 2008 Change in plan guys, I went to go pick up the orbital deep cycle battery, but the terminals were located on the side of the battery closest to the bumper. My cables weren't quite long enough to reach, and then I got to thinking, 200+ is a lot to shell out on a battery. Instead, I'm going to go with mssmith's recommendation to get a interstate mtp-35 battery. For 90 bucks, seems like best way to go. For the money if it dies I could buy another battery and still come out ahead over the deep cycle. I will post my reviews on it in a couple months or so and let people know how its panned out for me. *bump* for Tommyp if you're around.... I'm curious how the battery is working for you. I'm going to be upgrading my battery soon along with my stereo. Link to comment Share on other sites More sharing options...
msmith Posted July 2, 2008 Share Posted July 2, 2008 Well, if you want a testimonial on the Interstate, I've had one in my LGT (with a big stereo in it) for three years now and it's still perfect. I live in South Florida where the heat can be pretty hard on batteries and the Interstate Megatron series has always been the last battery I've ever bought in each of my cars. I've had one in my 92 VW Corrado, in my 98 VW Passat, in my 99 Mercedes ML320... I have one in the wife's 03 VW van... and all those vehicles had or have aftermarket audio systems. I've tried Optimas in some of our demo cars... I've tried "batcaps", I've tried all kinds of "car audio" batteries that make big claims but when it comes down to putting a battery in one of my own cars I always go back to Interstate Megatrons. When I find something that works and does so at a reasonable price I tend to keep doing using it. Call me crazy. Your mileage may vary, but that's been my experience. Manville Smith JL Audio, Inc. Link to comment Share on other sites More sharing options...
whobaru Posted July 7, 2008 Share Posted July 7, 2008 ^^^ Why can't I PM you? Link to comment Share on other sites More sharing options...
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