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

They all run $58.
but the numbers on each label are different. which of these is best suited for an alt delete?

Sorry - can't read the spec info from the pics posted.

I suggest you write the actual information to a web post and then it could be read.

You want:
12V = 12 Volt battery (I think one of them is marked 24?? But maybe it's a 24 month warranty)

Marine batteries will give "marine cranking amps". As long as you have several hundred MCA you should be able to start a small car's engine as long as it's not a diesel.

Amp Hours is the big important spec. Also called AH. More is better. 10 AH capacity means the battery could provide 10 Amps of current for an hour. Or, could provide 1 Amp for 10 hours. Same thing. Plan on buying 1-2 batteries of somewhere around 50-60 AH capacity each if you want to cover any serious distance in your car with alt delete.

Seems my car draws somewhere around 10A, running with headlights off. Headlights themselves seem to be about 15A or a bit more. So you can do some math and you get the idea of how much AH of capacity you need to drive for an hour or two or three.

Plan on using only about 20% of a lead acid battery capacity before recharging it. If you discharge more deeply, you'll get very few charge/discharge cycles before the battery is "toast".

In this price range, you might be best off buying two of them, as big as you can stand to use. Hook them together in parallel (so you get the same 12 volts, but double the AH). You'll probably get 3x or 4x the life for 2x the cost, because you'll discharge the double pack less and won't kill it off so soon.

Yup, can't read the specifics based on the pictures. Also, it doesn't help that the pictures are rotated sideways. I would say that a number of factors are involved, but generally speaking, the higher the Ah (amp hours) the better. Just be cautious because, in my experience, battery companies don't always list the Ah consistently. Basically, if it looks too good to be true, it probably is.

Ah ratings are typically at a 20hr discharge rate which is a very slow discharge. The faster you discharge a battery, the less Ah you can get out of them. If you discharge a 10Ah lead acid battery at 10A, or 1C (1C = 1X the battery capacity, 2C = 2X battery capacity would be 20Ah for this specific battery, etc.) you'll only get around half the capacity, or 5Ah out of it. This is called the Peukert effect. Lithium is a lot better than lead this way, but still it still suffers from the Peukert effect.

Also, it is alright to discharge a lead acid more then 20%. Most EV guys say 50%. The lower the better though.

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

sorry about the poor pics in the other thread.
I've resized them now. the 3 batteries seem similar in size, they all run around $60 i now see one is $68

they are all group 24 size batteries as it says on the label "24" , and I'd buy 2 batteries but I don't know the difference between the "24 dp" and the "24ms" etc.

http://imageshack.us/g/69/battery1x.jpg/


hope these pics in the link above work better

one says "dp" could that mean "dual purpose"? than its not a true deep cycle battery and no good for us. the another says "ms"

.

I checked it up.
dp is dual purpose. no good.
ms is "marine starting". no good.
24 dc is "deep cycle". GOOD.

@ Daox: Ive seen many LA batteries listing their 100hr discharge Ah rating. That's why I steer clear of 100 Ah batteries listed for ~$50. If it looks too good to be true... as the saying goes.

I'm not sure why you thing the DP is no good compared to the DC. The DP you have shown has a much higher Ah rating (105 Ah versus 75 Ah).

The structure of the lead plates are different. "Starting" type batteries have more porous plates to create more surface area and thus can put out more amps, but the lead degrades much quicker under deep cycling. You need a true "deep cycle" lead acid battery if you're even thinking about putting many cycles on them.

I also combined the OP's two threads in one to keep the info all together.

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?