BigMattyD Posted July 22, 2011 Share Posted July 22, 2011 0.56A is 560 milliamps not 56. More than enough to discharge a partially charged battery overnight. Can't believe that the computer said that was normal. Yeah, that's what I said. So you may need a new battery, but I would still be on the lookout for a current drain. Perhaps that's why your new battery died after a year. Most Car batteries are shallow-cycle batteries, meaning that they work well outputting a lot of amperage for a short period of time to start the car, but don't take well to prolonged current drain to low voltage levels. Matt Link to comment Share on other sites More sharing options...
idosubaru Posted July 22, 2011 Share Posted July 22, 2011 nice - i just saw the 56 and assumed 56 milliamps, good call guys. i still haven't gotten to mine yet. tracked mine down to the same circuit as the trip computer (but the trip computer was not the culprit). i have an aftermarket stereo in mine too though i unplugged the radio fuse which did not help, i suppose i may have tapped into a different wire for power or something....hmmm......be funny if we ended up with the same cause! good luck, this thing has been annoying! Link to comment Share on other sites More sharing options...
bstone Posted July 22, 2011 Author Share Posted July 22, 2011 Yeah, that's what I said. So you may need a new battery, but I would still be on the lookout for a current drain. Perhaps that's why your new battery died after a year. Most Car batteries are shallow-cycle batteries, meaning that they work well outputting a lot of amperage for a short period of time to start the car, but don't take well to prolonged current drain to low voltage levels. Matt The battery is an Optima Red Top, which I have always been told is the best type to have. Link to comment Share on other sites More sharing options...
BigMattyD Posted July 22, 2011 Share Posted July 22, 2011 The battery is an Optima Red Top, which I have always been told is the best type to have. Here is from optima website: "The OPTIMA® RedTop® high-performance AGM battery is the ultimate high-CCA starting battery designed to deliver the strongest 5-second ignition power for a reliable start-up every time. The RedTop will outperform and outlast traditional batteries in demanding cranking/starting applications. With unparalleled high power delivery and extreme resistance to the most common causes of battery failure, the RedTop is idea for trucks, SUV's, luxury cars, hot rods, off-road vehicles and other applications that require a leak-proof starting-only battery." I think this battery is optimized for high cranking amperage, but may not do so well for long term low level drain. It looks like their yellow top battery is designed for that: "The YellowTop® high-performance AGM battery is one of the only true dual-purpose automotive batteries available. With premium cranking power and unparalleled cycling capability (rechargeability), it is perfect for modern accessory-loaded vehicles. The YellowTop can repeatedly bounce back from deep power drains to full energy capacity, so it can power plenty of electronics and still start you up time after time. Lower internal resistance also provides more consistent power output and faster recharges." Their Blue-Top Marine/RV battery seems even better suited to long term current drain, but has less initial starting capacity. So, as far as Automotive batteries go, it seems that there is a trade-off between high initial cranking power and long term drain and recharge capability. If you have a modest, but noticeable current drain, and you are effectively deep-cycling your Red Top battery that is designed to be a shallow cycle battery, it will wear out much more quickly than a yellow or blue top. Matt Link to comment Share on other sites More sharing options...
bstone Posted July 22, 2011 Author Share Posted July 22, 2011 Matt, It appears you're right. I gotta find the source of this drain. Link to comment Share on other sites More sharing options...
bstone Posted July 22, 2011 Author Share Posted July 22, 2011 Just tried to use the ammeter on a multimeter. Nothing. Please see this video: http://www.youtube.com/watch?v=7lPwNc3VjuQ Link to comment Share on other sites More sharing options...
BigMattyD Posted July 22, 2011 Share Posted July 22, 2011 Ok, here's why it didn't work: You need to put the ammeter in series with the circuit you are testing. That is, you need to disconnect the positive battery terminal, then put one probe on the battery terminal, and one probe on the battery connector you just took off. The current actually has to flow THROUGH the meter. You have it in parallel, which is what you do to check the voltage. Do it like this: [(+)bat terminal ]<pos probe---meter----neg probe>[(+) Battery lead wire] So again, the connector on the battery must be removed, and you put the meter in between the battery and the battery connector you just removed. Matty D Link to comment Share on other sites More sharing options...
bstone Posted July 22, 2011 Author Share Posted July 22, 2011 Ok got it will try again once the sun begins to set and it gets below 110F. Thanks for setting me straight. Link to comment Share on other sites More sharing options...
BigMattyD Posted July 22, 2011 Share Posted July 22, 2011 Ok got it will try again once the sun begins to set and it gets below 110F. Thanks for setting me straight. Why are you being so lame? Get out there and work, man!! No way, I'm just kidding. No need to undergo heat exhaustion for such a thing. I am at work, and it is over 80 degrees with the AC on in here. Matt Link to comment Share on other sites More sharing options...
bstone Posted July 22, 2011 Author Share Posted July 22, 2011 UPDATED NEWS FLASH: After driving 130 miles from New Haven, NH to to Boston, MA I went right to Advance Auto Parts and had them test the battery. It again came up bad, 530CCA or 720CCA. They replaced it under warranty. I hooked it up and let the car run. Then they came out and did a new battery and drain test. The new results! Battery Test: Voltage: 12.34V Measured: 1256 CCA Rated: 800CCA Temp: 116 F Drain Test: 0.02A "PASS" The new drain is WELL within spec. The old drain was 0.5A, way above spec. I am going to see how things go, but I think it highly likely that the old battery was simply bad. I hope this is the end of the saga. Link to comment Share on other sites More sharing options...
bstone Posted July 22, 2011 Author Share Posted July 22, 2011 Why are you being so lame? Get out there and work, man!! No way, I'm just kidding. No need to undergo heat exhaustion for such a thing. I am at work, and it is over 80 degrees with the AC on in here. Matt 80 sounds lovely! It's 92 in my apartment WITH THE AC ON! Link to comment Share on other sites More sharing options...
BigMattyD Posted July 22, 2011 Share Posted July 22, 2011 Well it sounds good now. 0.02 amps is 20 milliamps. That is a normal amount of current drain. Good job getting a replacement battery. Link to comment Share on other sites More sharing options...
bstone Posted July 25, 2011 Author Share Posted July 25, 2011 Well folks, I think it's solved. Several days of driving, letting it sit for 24+ hours and another battery test shows that everything is hunky dorey. The old battery was just a dud. I think (hope) this one is licked! Link to comment Share on other sites More sharing options...
Rpm90001 Posted July 26, 2011 Share Posted July 26, 2011 Great! Glad to see it was just the battery. That's an easy fix. Link to comment Share on other sites More sharing options...
idosubaru Posted July 26, 2011 Share Posted July 26, 2011 who wants to continue battery drain diagnosis? mine (XT6, i know wrong gen) was off the charts until i unplugged my aftermarket stereo last night. i only unplugged the harness though - all the sliced in wiring is still in place. the drain is now 200 mA is the spliced in hack job wiring enough to cause a drain or is this something completely different? i narrowed it down to one fuse and have just about every item powered off of that fuse unplugged. Link to comment Share on other sites More sharing options...
Cougar Posted July 27, 2011 Share Posted July 27, 2011 If the splice is suppling power to something else then it could be tied to the trouble but if there isn't anything tied to the splice then that won't be a problem. You need to track down whatever else is tied to the fuse circuit and find what is causing the extra current draw. Normal current draw should be around 20 milliamps. Link to comment Share on other sites More sharing options...
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