What battery do you guys recommend ?

[BBKNARF]

Or doe's it matter, right now I'm using a Optima red top 720 c.c.a. its over 6 years old and its loosing its charge, the alternator is fine its pushing out 153 amps.
The battery will be mounted in the trunk, it will be feeding a MSD system, duel electric fans, and electric fuel pump, maybe electric water pump in the future.
Any suggestion, thanks.

Frank

[tradercraig]

trunk mount? do yourself a favor- get the kit to make sure you get the right size wire...proper connectors, mounts, etc...btw why are you going trunk mount?

[BBKNARF]

trunk mount? do yourself a favor- get the kit to make sure you get the right size wire...proper connectors, mounts, etc...btw why are you going trunk mount?

Yes I'm using the proper trunk mounting kit from Taylor, I love taking my car to the track when I get a chance, by moving the battery to the rear is good for weight transfer to the rear for better lauches.

[RD]

optima's are great due to their spiral cell design and ability to mount anywhere (to include upside down if you are creative).  They hardly ever go bad.  I am talking up o'reilly's right now, but they have an AGM battery (absorbed glass mat) that is very comparable to a red top but is a little cheaper.  you may want to check it out.

i have always used the 65EXT or 34/78EXT battery from o'reillys.  they are 3 year free replacement 84 month prorated batteries that have nationwide warranties.  they are around 94.99 exchange.  There is a 27-72 battery that is a direct replacement for a old style big mopar battery, has around 1000 cranking amps.

[Big Sugar]

While yourinto the electrical You may as well go the Mad Electric route  and get a start em up kit a Amp bypass and relay your front headlights.


Ron

[elacruze]

Or doe's it matter, right now I'm using a Optima red top 720 c.c.a. its over 6 years old and its loosing its charge, the alternator is fine its pushing out 153 amps.
The battery will be mounted in the trunk, it will be feeding a MSD system, duel electric fans, and electric fuel pump, maybe electric water pump in the future.
Any suggestion, thanks.

Frank

Do you mean 15.3 volts? If so, that's a little high for any battery, and AGM batteries like a little less than standard wet batteries. Are you sure you don't have some parasitic drain on the battery? 6 years is old for a battery these days, but not a record for AGM.
Whether you go new or not, I'd look into my voltage regulator and get it to 14.5 volts max.
I keep all my stuff at 14v max, but the tradeoff is that it takes longer to regain full charge; so if all your driving is short-trip you run the risk of keeping the battery less than full which is bad for battery life and I-left-my-headlights-on-now-my-car-won't-start.

Here's a great link, showing just how complicated battery charging really is; this is why new cars have computer controlled alternators instead of simple regulators like ours.

http://www.bdbatteries.com/mcharging_procedures.php

[BBKNARF]

Sorry its not 153 amps its 132 amps and yes maybe your right about the short trip drives is this why my battery is not keeping a full charge ? according to the shop I took my alternator to the guy said its pushing out 14.1 volts and 132 amps.

[greenpigs]

Rather than relocate the weight in the rear does anyone use something like this? http://www.jegs.com/i/Braille+Auto/147/B129/10002/-1

[elacruze]

Sorry its not 153 amps its 132 amps and yes maybe your right about the short trip drives is this why my battery is not keeping a full charge ? according to the shop I took my alternator to the guy said its pushing out 14.1 volts and 132 amps.

Your alternator is fine then, and not overcharging. Keep in mind that 132 amps is max, at an unknown engine RPM. It will have much less capacity at low RPM.

The old rule of thumb used to be 1/2 hour run time to completely recharge a battery from a single start.

Consider that your starter may draw 200 amps for 15 seconds while starting, so if your alternator is only making 15 amps at idle it would take 6 minutes to recharge the battery IF the battery could charge as quickly as discharge, which it cannot. Plus, your ignition, radio, headlights, wipers, blower motor etc. all take current away from charging the battery. Only a calibrated inline amp meter can tell you how much current is actually going back into the battery.
If you suspect not enough run time, let the car run in the driveway for 5 minutes before you leave, and a minute or two after you arrive and see if it gets better.

[Rolling_Thunder]

Odyssey   

[68charger383]

Right now I'm using a Optima red top 720 c.c.a. its over 6 years old. Any suggestion, thanks.
Frank

You got 6 years out of the old one, so buy another Optima.