here are 3 deep cycle batteries for alt delete, what are the differences+BIG pics

[Daox]

You have the numbers right there for the batteries plus batteries (thats what I'm running in the Paseo, a group 24). Lets look at the group 24 for example. It is rated for 150 minutes at 23A. 23A is .3C for a 75Ah batter. C rating will allow you to more easily compare to other battery sizes. So, you get 23A for 150 minutes. 150 minutes is 2.5 hrs. So, 2.5 * 23A = 57.5Ah of capacity @ 23A discharge. So, you only get 76.6% of the rated battery capacity at a .3C discharge rate. You can probably use this as a general rule but I'm sure it will differ from battery to battery. I know of no chart that will tell you the losses at different discharge rates. So, you can very easily imagine that "125Ah" battery from walmart is actually way lower at any significant rate of discharge. If it were just between the walmart and batteries plus batteries I'd definitely go for the batteries plus batteries.

[California98Civic]

Originally Posted by mans

Wal Mart has a 125ah deep cycle battery for $81. It's 125 ah @ 1amp.
they have a 100ah@1amp for $70
And a 75ah@1amp for $60

Batteries plus has a group31 100ah @23amps for $110.
They say it goes 225 mins@23amps +a reserve of an additional 185 min before its depleted(emergencies only I guess)

Batteries plus has a group 27 for $100
It's 90ah at 23amps it goes 200 min+reserve of 175 min.

And a group 24 for $90 it's 75ah at 23amps it goes 150 min with a reserve of 140 min.

If the wal mart batteries are Only slightly inferior to the batteries plus ones i'd go in that direction(of course) but im having a difficult time comparing them cuz the Walmart ratings are at 1amp and the batteries plus ratings are at 23amps.

How severe is the "peukert"Effect ?
Is there any type of chart that I could use to help figure out the power a battery would give at 23amps from the given numbers of 1amp?

I agree with daox that the batteries plus units sound quite superior. Frankly, the walmart battery sounds like crap. But no matter what you buy Brucepick is right. You don´t want to run these batteries down too far, below say 20%, before charging them fully or you will shorten their life and defeat the purpose of saving money on gas. That means you wil not get to use the full amp hours you are seeing on the labels. Night driving will deplete the battery faster. Get a good charger. Mine is 6amps and on the small side though the Odyssey reps tell me that is adequate if I do not discharge the battery below 20% much. Good luck!

[Ladogaboy]

I wouldn't recommend going further than 50% depth of discharge on a lead acid battery, even if it is a deep cycle.

[mans]

Peukert's law - Wikipedia, the free encyclopedia

under "external links" there is a calculator showing that a battery that gives 100ah at 1 amp gives only a tiny fraction at a higher load of 20 or so amp draw.

according to the chart a battery that is 125ah at 1 amp is absolute total dirt at 23amps, due to the peukert effect allowing for a battery to last an incredible amount of time when discharged so slowly. have a look at the calculator.

it's hard to believe the wal mart battery is so bad, I'd love to try a $60 battery from wal mart and a $60 battery from batteries plus and see how it goes...

[Tesla]

Here's a sit I stumbled across, thought I'd do a quick search before posting.
Deep Cycle Battery FAQ
Have a read and do even more research.
Not sure what your CCA requirement is, but if you plan to go from a starting battery to alternator delete and a deep cycle, plan to go at least 2, if not 3 times the weight to do it properly.
I would not advise going two 12V in parellel as when they, and they always do age and become unequal the can go into cyclic charge and discharge of each other till both batteries are flat, otherwise you will need to include high amp isolators so batteries are disconnected when engine or charging is off. A better system would be to use 2x 6V deep cycle batteries in series, still giving 12 V, but no need for isolators, if one fails you replace it, still ok to continue with two unequal batteries, just maximum current is governed by weakest battery, but doesn't affect efficiency of system.
You probably need to extend your research into the traction battery area/ stand alone power supplies.

[California98Civic]

The Odyssey PC1200 battery was designed for cars, weighs about 40lbs, rated 44amp hours, has 78 minutes reserve at 25 amp load, and offers 1200 cranking amps in first 5 seconds. Three year warranty. It costs more, but properly treated and charged it has a design life of 8-12 years. I'm running one of these now (for just a couple days) with my alt cut-off switch and so far I'm very very pleased.

[mans]

Originally Posted by Tesla

Here's a sit I stumbled across, thought I'd do a quick search before posting.
Deep Cycle Battery FAQ
Have a read and do even more research.
Not sure what your CCA requirement is, but if you plan to go from a starting battery to alternator delete and a deep cycle, plan to go at least 2, if not 3 times the weight to do it properly.
I would not advise going two 12V in parellel as when they, and they always do age and become unequal the can go into cyclic charge and discharge of each other till both batteries are flat, otherwise you will need to include high amp isolators so batteries are disconnected when engine or charging is off. A better system would be to use 2x 6V deep cycle batteries in series, still giving 12 V, but no need for isolators, if one fails you replace it, still ok to continue with two unequal batteries, just maximum current is governed by weakest battery, but doesn't affect efficiency of system.
You probably need to extend your research into the traction battery area/ stand alone power supplies.

tesla, thanks for the excellent link.
as per the chart in the link a wal mart battery with a 125ah rating at 1 amp is likely no better then 100ah when placed at a 20amp draw.

these batteries are made for wal mart by johnson controls. i don't know much about them but i will likely go with something else.

[Daox]

Originally Posted by Tesla

Not sure what your CCA requirement is, but if you plan to go from a starting battery to alternator delete and a deep cycle, plan to go at least 2, if not 3 times the weight to do it properly.

I have a group 24 which really isn't that much heavier than my stock battery. It can easily put out the amps to start my 1.5L engine in the Paseo. I have measured the amps required to start the engine and it spikes up to about 200 for a split second and quickly comes back around 90 before the engine starts. I wouldn't worry about cranking amps unless you truly have a massive engine or perhaps diesel.

[mans]

Originally Posted by Tesla

Here's a sit I stumbled across, thought I'd do a quick search before posting.
Deep Cycle Battery FAQ
Have a read and do even more research.
Not sure what your CCA requirement is, but if you plan to go from a starting battery to alternator delete and a deep cycle, plan to go at least 2, if not 3 times the weight to do it properly.
I would not advise going two 12V in parellel as when they, and they always do age and become unequal the can go into cyclic charge and discharge of each other till both batteries are flat, otherwise you will need to include high amp isolators so batteries are disconnected when engine or charging is off. A better system would be to use 2x 6V deep cycle batteries in series, still giving 12 V, but no need for isolators, if one fails you replace it, still ok to continue with two unequal batteries, just maximum current is governed by weakest battery, but doesn't affect efficiency of system.
You probably need to extend your research into the traction battery area/ stand alone power supplies.

I think I am going to go with 2 golf cart 6v batteries. They are rated around 225ah each one , when wired in series it should produce 12v and --> 450ah


Correct?

[Daox]

Nope.

series = add voltage, same amp hours
parallel = same voltage, add amp hours

Sorry, can't have both.