I guess the bigger question you guys mabye can help with , is I have heard while running in a parallel with two 12v batteries it won't charge right and vehicle manufacterers don't recommend it, that is why they make the switch to charge and use one or use one while charging the other.




Most all of diesel pick ups in the U.S. run two batteries in parallel without an isolator switch. They charge the batteries at the same time with the alternator. The batteries need to be in good condition. If one is week it will take the good one down with it.

It's recommended that if one battery fails that both should be changed, although I know of many that don't do that.

 

what is a good place ato put a secondary batterie in a 96 f150 4.9

 

I goofed that up. That first statement is a quote from a previous post.

STUPID COMPUTER!!

 

No problems, I am not important enough to be quoted, lol.

Yeah that is what I was refering to one of the problems with a 2 battery set up (why it is more expensive and will cost near what an upgraded alternator would be) is if one battery is weaker than the other the current flows to the weaker one. If one goes definately replace both, period.
You need 2 of the same rated battery, preferably same age, same brand and conditions. So, that would mean two new batterys which would be close to if not the same as the cost of a new HD alternator.

I have just heard that from people saying it won't charge right and vehicles manufacturers say do not do it, but i can't think of how it doesn't unless one battery's rating is different or its physically weaker. I think they don't know what they are talking about. I just figured newer light pickup diesels had "smart" charging technology built in, but probably not.

I still am partial to the switch idea, keeping one in reserve, i think it prolongs the life (as long as you keep the 2nd one topped off every now and then) and it allows you to use two different rated batteries or batteries from different ages or backgrounds which saves you $$ in the long run. (I am from AZ where in the heat most batteries last 1.5-2yrs, 3yrs if you are lucky, even the mighy optima doesn't last too much longer)

Most of the people I know that 4x4 and do this use the switch system, but then again the switches are promoted by 4x4 magazines and clubs etc and again its AZ.

 

Noneshere,

For whatever reason Wal-mart batteries have lasted the longest in my experience too, but I only bought or my dad's bought others from Auto-zone or checkers/advance auto.

The problem I have had and seen with wal-mart batteries is they last longer but when they died they did weird things....... ie faking it like it is a starter problem, acting like a short, and the list goes on.

A good load test never fails. I have been conditioned now to have a load test done everytime a starting/elec problem is present. (Its cheaper than having it towed only to pay premium at the mechanics for a battery job thought it was the starter(it wasnt me it was my dad that did that lol

Oh, one time it (wal-mart batt) corroded a near new battery cable stock rating... arghh, put in a new heavier gauge cable and now my dad only uses auto-zone year in half batteries. lol (Says he likes the pro-rating warranty better) I think he likes to look like he is doing car work and is jealous of all the cool "easy" car work I get to do becuase these fords are easy to work on

 

To find out the draw that your amp has just look at the fuses and their ratings. My amp has two green 30 amp fuses so thats sixty amps at full power. Needless to say at full power it dimms everything in the poor old truck.

 

Oh yea, I agree optimas are expensive but I've gotten two free replacements so I'm not complaining. 3 year free replacement for the win. Oh and just so you know I think I murdered one of them. Lol.

 

well, im having to replace my battery cause i killed it with my sound system. I drained it so badly everytime i drove and i guess the alt couldnt charge it back up. But it got ruined in 2 years of running good and 3 months of having a sound system.

 

RoadVirus how did you murder your optima???

Sounds like it would be an intersting story or a good don't do that lesson for us

 

you NEED to upgrade the alt
www.fordfuelinjection.com
this site will give all the info needed for the upgrade
I feel you should also add the second battery
you can do this with switches or with an isolator (diode pack)
the batteries need to be isolated when not charging
this prevents one battery from draining the other
when the cells are unequal in quality
this is the same thing that happens when one cell of
a battery dies but the other 5 still work well
over nite the one weak one kills the other 5
it is probably advisable for you to go up to at least the 130 amp alt

while the engine is running the electrical system is operated by the alt.
the battery is recharged to its full capacity and only
used when the alt. does not produce enough to keep up with demands

 

i've gone through about 3 optimas so far...

nothing wrong w/ my electrical... my errors...left headlights on door open etc. But battery woulden't hold a load after it went dead. Luckyly the optimas have an amazing 3 year free replacement warranty which has ALWAYS been a plus so far..