Battery dead after 21,000 miles

[Mad Hatter]

Heard a slight whistling sound from the engine bay on the way home from a track day. Was not sure what it was so stopped by my mechanics shop and had him take a listen. He said check the battery, looks like the alternator is working harder then is should. Sure enough 2 cells are all black inside and a computer battery checkup gave only 45% charged. Is the battery the same as the stock GT? and are their any even lighter options??

 

[TMSBOSS]

Heard a slight whistling sound from the engine bay on the way home from a track day. Was not sure what it was so stopped by my mechanics shop and had him take a listen. He said check the battery, looks like the alternator is working harder then is should. Sure enough 2 cells are all black inside and a computer battery checkup gave only 45% charged. Is the battery the same as the stock GT? and are their any even lighter options??

If the charging system is "Cooking" the battery, a battery swap will likely result in the same results.

Have the systems checked while/before replacing the battery.

Has your tech added fluid to the battery, recharged and retested?

Running a cell dry or low on fluid does reduce the life span of the battery some what. Does not kill the battery every time.

The GT battery is different than the Boss battery.

The Boss battery is lighter and therefore probably less durable.

Yes, there are several light weight batteries on the market. Cost to return has never been positive for me. The few pounds saved are expensive.

Good luck with the repairs.

 

[Pitt302]

My Battery was getting hot to touch in the engine bay,bought a thermal protection kit to wrap the Battery.Dont know if the could be the cause, but my Battery was getting very hot before the thermal wrap.

 

[Darth Boss]

Mine died last week, they are crap but under warranty.

 

[seca954]

I only got about 6000 miles on my factory battery. I didn't get it warrantied because it was easier to have my wife pick me up and drive me to the auto parts store.

 

[WinterSucks]

I would relocate it to the trunk. you don't save weight and add the weight of the wires, but at least you are getting weight from up high in the front to lower in the rear. I think those kits will pay for themselves considering the weight distribution benefit and the cost of a lighter battery in the stock location. Plus engine heat isn't a concern anymore. Which might shorten the lifespan of an expensive battery anyways.

 

[F.D. Sako]

Question for you guys with the dead batteries. How do you drive your boss, is it DD, or only a weekend/summer car and has been put away for a couple of winters?

 

[seca954]

I would relocate it to the trunk. you don't save weight and add the weight of the wires, but at least you are getting weight from up high in the front to lower in the rear. I think those kits will pay for themselves considering the weight distribution benefit and the cost of a lighter battery in the stock location. Plus engine heat isn't a concern anymore. Which might shorten the lifespan of an expensive battery anyways.

Perhaps if it's a race car. If it's a street car, it's not worth the effort. You'll need an oversize battery to always get you started after it gets hot. You also need a kill switch mounted externally. I was actually happy to see the current placement of the battery. It's a big improvement over previous generation mustangs.

 

[Mad Hatter]

Question for you guys with the dead batteries. How do you drive your boss, is it DD, or only a weekend/summer car and has been put away for a couple of winters?

Mine is driven about 3 days a week as a semi DD as well as 1 to 3 track days a month

Sent from my GT-I9100 using Tapatalk 2

 

[WinterSucks]

Perhaps if it's a race car. If it's a street car, it's not worth the effort. You'll need an oversize battery to always get you started after it gets hot. You also need a kill switch mounted externally. I was actually happy to see the current placement of the battery. It's a big improvement over previous generation mustangs.

Street car vs track car there is a convenience issue, sure. I get the impression that Mad Hatter tracks more than enough to not mind having a battery in the trunk as long as he can still fit track tires somewhere. I am not sure what you mean about needing a bigger batterywhen it gets hot, though. It will surely stay a hell of a lot cooler in the trunk. And I can't believe I had to add "hell" to my android dictionary...whaaa?

 

[So Boss]

If Motorcraft batteries are not that good, then what are the better alternatives?
-i.e anyone using Optima?

 

[seca954]

Street car vs track car there is a convenience issue, sure. I get the impression that Mad Hatter tracks more than enough to not mind having a battery in the trunk as long as he can still fit track tires somewhere. I am not sure what you mean about needing a bigger batterywhen it gets hot, though. It will surely stay a hell of a lot cooler in the trunk. And I can't believe I had to add "hell" to my android dictionary...whaaa?

This is what I meant by hot. I've owned three different mustangs with the battery relocated to the trunk. I live in South Florida. All three of them were slow to start when the ambient temperature and the car was hot. IMO it's not worth the effort to relocate the battery to the trunk unless it's a race car.

 

[TMSBOSS]

Heat effects not only the battery. The cables and starter are degraded by heat.

So when under hood heat goes up, more power is needed to crank the starter.

Older big block Vettes were nitorious for not starting when hot. Let it cool down and it would crank right up. I have had two, both had this problem.

 

[576]

Wondering if anyone has an operating voltage reading at the battery terminals with car warmed to operating temperature? Or does anyone know of a spec. Just changed the battery in my '12 and seems like I may have an over-charging situation. But, I have no comparison. I did put in the GT battery. I guess I won't have that breakfast burrito before the next track day to balance out the extra weight. Thanks.

 

[VoodooBoss]

Does anyone have a recommendation for a battery similar to the stock Boss battery? Mine's due to be replaced as well and the indicator light is now orange.

 

[Senderofan]

Does anyone have a recommendation for a battery similar to the stock Boss battery? Mine's due to be replaced as well and the indicator light is now orange.

Well....I had Three wonderful FOMOCO batteries give up on my this year. The Boss and then my two in the F 350. I went with Odyssee for all three. For the Boss...I have a PC1200MJT....1200 cca...which is a more robust battery that should hold up better in cold as well as hot temps. It weighs more than the OEM....but is built much better. Just my 2 cents worth.

Wayne

 

[bullitt]

My Boss battery just died -- went out to take grandson for a ride, and all I got was a click and dead as a hammer -- but upon sitting for a few minutes read 12,8 volts on volt/ohm meter. Tried to start again and same click, no lights, radio, etc. Battery is 3-1/2 yrs old, as is car, purchased 11/2012, and has always been on battery monitor. 10k miles on Boss now. Would NOT jump start with a fresh battery! Any info will be appreciated!?????

 

[thehueypilot]

I like the Odyssey batteries for long life and no free acid. These batteries were developed first for military applications and spread into the civilian market. They are pricey but if you have ever kept a car long term you will see a lot of rust develop around the battery tray from the free acid filled battery. I have these in all my hobby cars with 10 plus years of staying power. The part number below is supposed to fit a 96R BCI battery group which fits the Boss. Note: the price I got was $247 from the manufacture but Summit will match it. I had to modify the nylon hold down strap by adding a new hole with a hot soldering iron tip and added (epoxied) delrin blocks to the left and right battery tray stops. I epoxied them on and painted them black with spray paint for plastic. The insulation for the stock battery is a little big on this smaller battery but it should still insulate the battery from direct heat.

http://www.summitracing.com/oh/parts/ody-pc1200mjt
http://www.batteryweb.com/bci.cfm
http://www.odysseybattery.com/battery_search.aspx

Tim
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[LikeABauce302]

My Boss battery just died -- went out to take grandson for a ride, and all I got was a click and dead as a hammer -- but upon sitting for a few minutes read 12,8 volts on volt/ohm meter. Tried to start again and same click, no lights, radio, etc. Battery is 3-1/2 yrs old, as is car, purchased 11/2012, and has always been on battery monitor. 10k miles on Boss now. Would NOT jump start with a fresh battery! Any info will be appreciated!?????

I had the same issue 2 weekends ago. My 2012 Boss has 18,000 miles on it. I took it to an autocross and ran the car all day without issue. When I went to leave at the end of the day, my car wouldn't start. I tried jump starting it, but it wouldn't even crank. I had to have the car towed home.

Once I got the car home, I checked the voltage across the terminals and it was 12.8 volts. I then load tested the battery with a cheap Harbor Freight load testing tool and it failed. Voltage dropped immediately once a load was applied.

I went to Autozone and bought a Duralast Gold battery. It started right up once the new battery was dropped in.

 

[WinterSucks]

I have never heard of such an immediate failure of a battery before. I have always had plenty of warning signs in the past. Sounds like a good preventative maintenance item to do now... Or at least buy one, charge it, and leave it tied down in the trunk lol.