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Update - AAA told me that they'll tow me 3 miles, and it's $4.50 a mile after that. Rudtner's is 68 miles away, making it a proposition of $300 to get it there.
So, if I were to put in a new battery and just wrap a garbage bag around it, even if it dies, that's about $120, making me lean toward the sacrificial battery option. Thoughts?
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i forget that a lot of you are pilots. i meant for the engine generators at the facilites like he said above
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Quote:
Listen, Optima batteries take a 15 volt charging voltage, that's what they like. To blow one up requires that the charging voltage is WAY in excess of that number, maybe 17-18 volts. The reason it blew up is that when the battery charges, gas is released from the cells which leaks out of the battery through calibrated vents. (they aren't really "sealed." When the charging rate goes too high, "somethin's gotta give." If you want to use a new battery, that's OK, but you should absolutely monitor the charging voltage, either with a plug-in cigarette lighter voltmeter, available for like $25, or put your voltmeter set to the volts scale on the battery terminals with the car running. My guess is, it's off the scale. It's a VERY common failure mode for the later voltage regulators to fail in the full-field position. The problem, as I said, is frying everything electrical in the car. I suppose you could change the VR yourself, pull the alternator, look at what you have, order replacement VR from our host, install (takes a few minutes) and then reinstall a new battery and test. That would take probably four hours if you've never done it before with coaching from the Board. I would call Billy, a calm professional is a good asset at a time like this.
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I have owned many Optimas and they all failed quickly.
They do not charge well. If you dont use a trickle charger and do let it go down it will not charge back up from a regular charger. I used to have to use jumper cables just to get them charged up enough to let a regular charger finish them up. I have had several friends report the exact same thing thay also gave up on Optima. I even took two of them in to the dealer that sold them to me and they tried to charge them for days and gave up and gave me two new batteries which a year later also pooped out. Optima=JUNK For everyone who loves them, fantastic keep buying them, for me after four trys 2 red tops,1 yellow top and 1 blue top never ever again. I will stick to Odyssey.
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My suggestion, take a borrowed battery and connect to the system with jumper cables. Connect a voltmeter to the + and – terminals, then start the engine. Observe the charge voltage. If it's much above 15 volts, don't drive the car as the battery will overheat, perhaps rapidly. A battery will withstand a slightly increased charge voltage for 300 miles, but to increase the safety margin (reduce the charge rate), switch ON the following accessories: headlight high beams, fan, A/C. radio and rear window defroster.
Understand the higher charge rate causes the alternator to operate outside of normal operating conditions which may reduce its service life. Sherwood |
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Well, the plot thickens. I used a meter and I'm getting an almost dead even 14 volts across the rpm range (up to 5k), checked both at the cigarette lighter and at the battery.
I had used a battery charger on the dead optima, after jumping it twice (died but held a small charge after the first attempt, got me around with several stop and starts for a day following the second jump). attached the charger just to top it off, before reading that it was bad to let the car charge it on its own here. So this gives me a measure of confidence that I can at least get to Bill on my own steam. But it also takes out? the primary suspect in the issue, which was a faulty vr. Could the vr be on the fritz, and be going in and out? or do they typically fail catastrophically and that's it? Again, thanks for all the info.
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As I said earlier - you damaged the Optima by deep-cycling it. Then, the charging circuit on your car got really confused because the damaged Optima had a high internal resistance. This caused the overvoltage and the Optima responded less than adequate to that......
Chances are once you get a new battery all is fine. Just monitor your voltage from time to time. There are those gadgets that plug into the cirgarete lighter plug. Maybe get one of those. And if you have a planned non-op time of more than 2 weeks do yourself a favor and get a trickle charger. Works perfect and the battery will thank it with long life. Ingo
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If you want to kill the alternator, remove it from the car and throw it off the GW bridge.
Seriously now, jump starting? Automotive starting batteries are designed to drop to about 97% of full charge during a prolonged starting attempt in the winter-- then be recharged back to full in normal operation. When you deep cycle them down to 25% charge (12.2v or lower) they undergo physical changes, shorted plates, all kinds of problems. The car's alternator, too, is designed to top the car up from a "long start" situation and handle the normal running loads. When you use it to bring the battery back from the dead, it goes to maximum output in an effort to do that-- which also means maximum heat. The fact that this whole operation is going on 4" from the engine block inside a fiberglass shroud makes it worse-- particularly when you turn the engine off- the heat then builds up and cooks the diodes and the regulator. This heat-soak of the regulator is the reason why the Paris-Rhone setup gets such a bad rap by the way-- heat is the enemy of electrical components. Anyway, don't jump start your car except in an emergency-- then find out what the problem is and correct it immediately so you don't end up writing a BIG check instead of a small one. . . Can you make our next McSorley's outing? You deserve a cold beer after suffering through this. (not my post, that's bad enough, I mean the exploding battery syndrome)
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How do you know this? Do you know someone at Valeo?
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Here is the factory workshop manual page with specific guidance on the point.
![]() I will check the Bosch Automotive Handbook tonight, I think the same information is presented there (I have the Seventh Edition). I don't have a friend at Valeo but I do have one at Bosch. It shouldn't take long to establish that trying to charge a battery with shorted internal cells, or one that has been discharged to 11v, wasn't part of the design criteria.
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'66 911 #304065 Irischgruen ‘96 993 Carrera 2 Polarsilber '81 R65 Ex-'71 911 PCA C-Stock Club Racer #806 (Sold 5/15/13) Ex-'88 Carrera (Sold 3/29/02) Ex-'91 Carrera 2 Cabriolet (Sold 8/20/04) Ex-'89 944 Turbo S (Sold 8/21/20) |
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I was going to say that you guys are mean, but then you said beer so we're friends again. I am glad to hear your opinions. I also checked with Matt over at Bill's shop. His thoughts echoed yours, both in the cause and the prognosis.
I'll keep an eye on things, and take it slowly from here. They're going to do some analysis at Bill's shop while they have it in for other work, so I'll let you guys know if we find anything. When is the next Mcsorley's outing? is there an email chain or something?
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89 Carrera 3.4 "There is a right way to go around a corner - it's called the line." -- PCA DE speaker bryteside.com - good things happen. |
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Quote:
![]() I'm absolutely SLAMMED at the moment but I think early August looks promising. I'll try to get Gytis to bring some original bits from his 68 TR barn find. . .
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Does it take more to charge the yellow top. Will that tax our alternators too much so that it will never get fully charge? I am in the process of replacing my 3rd red top and am thinking about going with a yelow because it is design to charging and discharging.
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oh no! should I panic? I just installed a new red top.
with the help of the forum posts about the cool cutting board holder. It is all fine and happy now. but if I ever think I need to put it on a trickle charger, like a battery tender, should I take it out of the car, or leave it in?
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Here is further information from the Optima batteries website:
Quote:
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Quote:
http://www.optimabatteries.com/product_support/charging.php Generally speaking, even though the Bosch voltage regulator has a set-point of around 13.8v, the high resistance connections found in most old Porsches could result in a reduction in charging voltage.
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'66 911 #304065 Irischgruen ‘96 993 Carrera 2 Polarsilber '81 R65 Ex-'71 911 PCA C-Stock Club Racer #806 (Sold 5/15/13) Ex-'88 Carrera (Sold 3/29/02) Ex-'91 Carrera 2 Cabriolet (Sold 8/20/04) Ex-'89 944 Turbo S (Sold 8/21/20) |
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Here's some tech information from Optima I got recently when a Blue top exploded at work. We also use them at AT&T for emergency generators start batteries.
Hello Bob
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Quote:
I am thinking that a deep cycle battery like a Yellow Top will take an alternator longer to charge then a normal battery? |
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Quote:
If the battery is not defective (shorted cells) its terminal voltage will be 12 volts pretty quick. I wouldn't think there would be much power difference between that and 12.6 volts, fully charged. I remember the gold Porsche guy asked a Delphi engineer and he scoffed at the idea charging a discharged battery was bad for the alternator.
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