Dead Battery

[tylerzaath]

Originally Posted by Yom

keep believing it will last forever dude lol.

is a fault in the JK's programming. it simply sends too much voltage to the battery. the genuine optima will last a bit longer but it will suffer a premature death when fitted to a JK as well.

where is your source for this information? link??

[davidd]

as eugej posted the chrage rate for the optima is up to 15v and the optima website verifies this. my first battery buckled very early in life and went snafu not long after. the new one which is the genuine article charges at between 13.8 and 14.9 volts and works fine and no buckling. i'm sure there is the chrysler influence here in the factory battery.

[bbodybenny]

I believe that a lot of the problem is in the amount of vibration that the battery endures in the JK especially. Batteries dont like being bounced and jolted around, which is why there are 4wd and Marine batteries for sale at battery world. These 4wd batteries are braced internally to ensure the plates dont come loose of come into contact with each other. They are specifically designed to withstand harsh vibrations and jolts, and will stand up to a much harder treatment than the el cheapo factory units. Even sealed Gel batteries arent immune to these problems.
I used to go through big cranking batteries twice a year in my boat, until the battery guy asked me what kind of "car" i was using them in. I told him it was in a boat and he put me right onto the marine/4wd batteries and they have held up well for 2 years now. I have two in the boat, so replacing two at a time was costing me $400 each time!!!!
Dual battery system with a redarc dc/dc controller/charger is the way to go. Spare down the back in a battery box, with anderson plug charge wires, if theres no room in engine bay. ARK make a good battery box for $179.

[JAG811]

My factory replaced Optima just gave up the ghost. So second one in 3 years. In saying that they say 2 years tops out of a battery in the tropics ... in saying that PLENTY of people can prove that false...

A couple of points to add to the thread are that normal cranking batteries are designed for big shunts to start a motor but stop working once they're down to about 80% charge. Deep cycle batteries are not designed to take the starting shunts, but run effectively down to around 50% charge.
If deep cycle batteries are continually used for starting they eventually shit themselves.
So I can't work out WHY fit a deep cycle from factory ??

So in a dream world of no bills, money worries and or children, we all run duel battery systems starting the vehicle on the normal starting battery that can take the continuous shunt and then run all accessories (winch, fridge, converter, ect) off the deep cycle battery wired in .... I wish.

So I dragged out an old 720CC battery I had on the bench for the last year and I've been trying to reserect it from the dead over the weekend. Hopefully we'll see tomorrow if it can start the JK ... if 720CC is enough ??

[anthonygubbin]

Hey Jeep to Be, if it buggars up for good let me know and I can put you onto a bloke at Glynde. He sells marine ones 50-70 cheaper than anywhere else I can find in SA. These are not generic ones either they are proper brand name ones, like Century and Exide.

regards Anthony

[Yom]

Originally Posted by tylerzaath

where is your source for this information? link??

stick your multimeter onto it and watch the volts rise after its been running for a few minutes.

Charing specs for the Optima D31A. who knows what the mopar/chrysler version has been spec'ed for but its most likely the same.

Optima Yellow Top D31A Charging Recommendations.

Alternator: 13.65 to 15.0 volts; no amperage limit
Battery Charger: 13.8 to 15.0 volts; 10 amps maximum; 6-12 hours approximate
Float Charge: 13.2 to 13.8 volts; 1 amp maximum current (indefinite time at lower voltages)
Rapid Recharge: Maximum voltage 15.6 volts. No current limit as long as battery
temperature remains below 125°F (51.7°C). Charge until current drops below 1 amp.


My alternator will push up to about 15.8v according to my multimeter. 51.7 degrees celcius...I think it gets that hot just sitting in the sun!

Also the Mopar/chrysler optima D31A is a hybrid deep cycle.

But then the Mopar/Chrysler part is different to what you buy off the shelf here. Mine went from an 800 something CCA to a 975cca which is silly huge. Off the shelf at your local shop the D31a is 900cca.

Who knows what we're actually getting in them.

[Tassie Jeeper]

glad u made it home in 1 piece mate god that thing stunk (and u blamed the dog LOL)