batteries, batteries, oh we we love theeeeee...

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I'm upgrading the truck again... sort of.

I'm ripping the bench / speakers out of the bed and building something that's more like what I wanted in the first place. And I'm using one of my old subs in there as well with a 70A DPDT relay to switch between subs in cabin and subs in bed...

Anywho... I've got it all figured out, and I'll need somewhere around 500 amp hours reserve to get through two 2 hour movies at the drive in (4 hrs total obviously) and not have dropped the batteries below 60% depth of discharge.

So, I'm considering these guys --> http://www.partsamerica.com/ProductDetail.aspx?MfrCode=ATC&MfrPartNumber=27DC2&CategoryCode=3583

They're 95 amp hours each... so I'd be getting 5 of them... and my discount price would be about 55 bucks each. They're made by Johnson Controls so I'm not worried about the quality.

However, I don't want to deal with wet batteries of I don't have to -- I'd like to get sealed lead acid, but I can't find any that aren't $200 bucks a pop.

Anybody know where I can get sealed lead acid 100 AH units for a reasonable price?

P.S. - I don't want AGM batteries (ie. Optima), in order to get the reserve capacity that I need, I'd have to get something like 7 D34 yellow tops at $225 each. Standard lead acid trolling / marine batteries are far cheaper and will last just as long.

audiobliss

Just out of curiousity, and I don't mean to threadjack here, but what exactly is the benefit of an Optima battery?

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all the optimas are absorbant glass mat. instead of having sloppy liquid between plates, you've got a fibrous glass mat that absorbs that liquid and holds it in place. the result is that if you punch a hole in one, it's not gonna leak.

also, a certain amount of gell substance is added to the acid mixture. it's not a true gell battery, and that's probably a good thing because true gell cells suck... but anyway, this 'just a dash' of gell makes sloshy acid into 'not so sloshy' acid. it adds to the spill resistance and helps with recombination of gases.

further, all the optimas are sealed lead acid batteries... so you can tip them upside down and not worry about it. also, you never have to water them, whereas 'maintenance free' lead acids still need to be watered, even tho no one does -- if they did the damn things might last 10 years.

that's the end of the benefit for the red top optimas...

the yellow tops and blue tops are identical (except some of the blue tops have wing nut terminals instead of car sae posts -- but the guts are the same)... these batteries have thicker and more 'spongey' lead plates (which are actually in a spiral since all the optimas are spiral cell, hence the little 'beer can' look to the battery's case), that can handle being discharged more deeply. if you dump a red top (or any other starting battery) down to 50% or 80% depth of discharge, you're beating the crap out of it. you an only do it 2 or 3 times before you've caused damage. do it enough times and the battery just plain won't take or hold a charge. but after 2 or 3 times you start to loose reserve capacity... the battery stays charged for shorter periods of time under load. the yellow top and blue top can take 50% depth of discharge all day long - every day... and 80% depth of discharge once or twice a month .... under those conditions, the battery will last about 5 to 7 years... and that's considered a 'brutal beating' in my book... the red top or other starting batteries would be killed in a year.

but, if you don't care about whether or not you can punch ah ole in your battery, then a standard sealed lead acid hybrid deep cycle will give you the exact same performance (although admittedly a little more heat due to a greater internal resistance) as an optima yellow top. and a standard sealed lead acid starting battery will act the same as a red top. if you want to get really picky -- you can take a hybrid deep cycle wet battery and stretch its life out to 10 years at the same brutal pounding... but that requires you to constnantly monitor the water level between cells and all that ****.

audiobliss

Wow. Thanks for all that info. I didn't mean for you to spend nearly that long on it, but thanks. I appreciate it.