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Battery Discharge

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Hey guys,

I have parked my car since December 20th and now the car is dead every time I try to start her up. I was starting the car every two weeks and taking it for a short drive around the block, and it would start up just fine. Then one time, i accidentally "Armed" the car (I have a Clifford alarm) and after two weeks it died and wouldnt start. That wasnt a surprise so I boosted her, drove a little bit and then parked her again making sure not to ARM, but just lock the doors. That was about 10 days ago.

I tried firing up last night and the car dead again. She doesnt start and instead crazy ticking noises happen. The RPM and Speed needles raise a little or go below zero and vibrate and then go back to normal when the ticking stops. I boosted her again and she fired up. The on-board track aps screen is showing 14 volt charge while the car is running.

My question is if anyone else has experienced this and what the best way would be to keep this from happening? Battery charger? Any good brands?
+2. Also most modern cars have a small backup battery that is for management systems with volitile memory. The main going flat sometimes can take out the second. Put the car on trickle charge for more than four to six hours and see if it corrects your problem.
You could also find out what's causing the problem by measuring the current draw between the Neg. term of the battery and gnd, start pulling fuses to anything that was installed after you got your car. I'm not sure what the parasitic current draw should be on the battery, but less then ~ .250 amps, might be a good starting point. If that doesn't help I'd leave fuses out and let the dealer check it, you may have a problem in your electrical system that should be repaired under warranty. Chances are it's your alarm system, doesn't matter whether it's armed or not, it's still in standby mode. These batteries aren't as robust as a regular car batteries because of their weight savings.


#LS-378 - So many Porsche's, so little time....
Sounds like that Clifford alarm is drawing a little more current than one might think. +1 on the battery tender...


Save the dawn for your dishes!!!
yeah I have a battery tender. good investment. as for it going dead. in the manual it says if you leave the keys in the ignition it will drain the battery. so take the keys out of the ignition if you leave them in while its parked.

And I have found that factory batteries once drained to a point where the car wont start almost never recover. I would get a nice battery like a optima yellow top or red top. or since it is more than likely still under warranty take it to the dealer and get a replacement battery under warranty
Another vote for the battery tender, they are great. I have one for the Boss and the bike.

One question though, you said you drove the car around after jumping the battery, how long did you drive it around. If the battery was mostly dead it can take a long time for the charging system to fully charge the battery.

You could also take the battery up to the parts store and have them load test it for free. These battery's aren't meant to be completly drained and charged multiple times. I had it happen on my beater jeep. I left the interior light on while it was parked at the airport for two weeks. I got it jumped and drove home. But when I measured the voltage drop on a full charge it would drop to 7 volts, hardley started the car. It was just downhill from there.
I drove it for a few minutes and then the second time left it on in the garage for 10 mins. I will test it in a couple days. Will get a new battery from the dealer when I start driving in the Spring.

Any idea what the Mustang battery size is, the Optima website doesnt have Mustang as an option in their application search. Any other good brands out there?

Thanks guys for the response.


Save the dawn for your dishes!!!
sadil said:
I drove it for a few minutes and then the second time left it on in the garage for 10 mins. I will test it in a couple days. Will get a new battery from the dealer when I start driving in the Spring.

Any idea what the Mustang battery size is, the Optima website doesnt have Mustang as an option in their application search. Any other good brands out there?

Thanks guys for the response.
yeah I cant find a part number to one for the 11+ only to the 10 model
this is also a good battery I am told but they are expensive
odyssey part number PC1200MJT
The battery group size for the Mustang is 96R. I believe the R suffix denotes the terminals are reversed; that is the positive is on the right side. The heavy duty version is a size 40R. I just went round and round with CJ Pony Parts on an Optima Yellow Top they have listed as fitting the Mustang. The group size on the battery is 34, and the Optima Part Number is 8012-021. Optima does not make a group size 96R or 40R battery, and the 34 battery which will fit the battery tray has the terminal polarities reversed. So Optima will not show a drop-in replacement battery for the Mustang in a Yellow Top flavor on their website.

Please note that you have to remove 2 small insets on the bottom of the battery tray for the battery to fit (they just slide out). Also, the little blanket they have on the factory battery won't fit around the Optima, so you have to slice one side and either tape it on or cable tie it on. The Optima is about an inch higher as well, but this is not a fitment problem with hood clearance.

The big problem with using the Optima battery is the terminals are reversed. To get the positive terminal inboard on the right side you have to turn the battery around. Once you do this, the terminals are closer to the firewall and the battery cables will not reach. You either have to replace them, or use a set of battery cable extenders. I did manage to find a source for the battery cable extenders. They are available from REMY Battery Company, Milwaukee Wisc. (413) 384-0340. The cables have the standard post clamp on one end, and a stud on the other. They are about 6 inches long and have 4 ga cable connecting the ends. Part number is 5505-010 for the cables ($23.00), and 5515-2002 for the 2 posts ($3.00). They are very well made and will do the job.

As CJ Pony Parts was busy being less than no help, the folks at REMY also recommended another battery AGM type that is reputed to be as good as, if not better than the Optima. It is a DEKA Intimidater. The part number is 9A34R, and as you can tell from the R suffix, the terminals are right where you need them to be so you do not have to fool around with the battery cable extension. I did get the DEKA Intimidator for $146.00, and have been extremely pleased with it so far. Spec's and size are identical to the Optima, except the positive terminal is on the right side where you need it to be.

I'll try to post some photos of the cable extensions so you can see what I am talking about.

On a less happy note, I have to tell anyone who is interested NOT to buy ANYTHING from CJ Pony Parts. Not only are they not very knowledgeable about what they sell, they will not stand behind the products they sell. I ordered the Optima Yellow Top from them, and as soon as I saw that the battery cables were going to be too short I contacted them about it. Not only did they deny there was a battery cable length problem when using the Optima, they refused to issue an RMA to take it back. I rarely return items, but when I do, it is for a good reason. I rarely get a run-around like I did from CJ Pony Parts followed by an outright refusal to take the product back. When I have encountered this problem in the past, the business who is giving me grief about a return is usually either in financial distress or is very poorly managed. In any event, they should not list the Optima Yellow Top as an option for the Mustang with the only fitment note being about minor adjustments to the battery tray. CJ Pony Parts can go to he double hockey-sticks as far as I am concerned.
Hopefully I finally figured out how to upload photos. Here are the photos of the REMY Battery Cable Extenders and their use on the Optima Yellow Top:

IMG_2841_zps6e772f73.jpg ][/img]


IMG_2843_zpsbe22e896.png ][/img]

IMG_2845_zps59ab7af6.jpg ][/img]
Would desulphating the battery maybe bring it back? A few of the CTEK charger/tenders have that feature. And can be permanently installed.

This is interesting, too. I might use it on my dd so I don't get stuck anywhere.

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