westend wrote:
I would bet those 52 anp scooter batteries are AGM and not gel. Gel is a more expensive battery and usually isn't used in scooters. This is a good thing.
Not always.
Per
HERE"Two types of deep-cycle batteries are used in power chairs and scooters: AGM or Gel. Both are a good choice, but AGM has two distinct advantages — it lasts longer and is approved for air transport."
So it IS possible to get high Ahr GEL batteries for scooters and wheel chairs.
Gel cells TEND to be CHEAPER than AGMs per Ahr capacity since Gels have been around for MANY years longer than AGMs..
It only has been recent in the last few years that AGMs have gotten less expensive to manufacture but they are still more expensive and you tend to get LESS Ahr capacity for the size and weight of the battery when compared to a wet cell.
If you don't believe me about the possibility of GEL cells in scooters and wheel chairs then take a look at the following link..
HEREUnless you REALLY NEED spill proof batteries, wet cells will get you the most Ahr capacity for the money.
If money is not object then have at it with the AGMs..
As far as running an inverter from three 52Ahr batteries, it can be done but you will not run it for long.. That is 156 Ahr capacity, AGMs take a major hit in life if you discharge them to 50%.. For longest life most AGMs should not be discharged more than 40% DOD..
That would be 62.5 Ahr capacity out of three of those batteries..
If you are not careful there are AGMs which have even LESS DOD capacity which is 15% - 20% DOD..
Hard to beat a Golf cart wet cell which can be discharged to 80% DOD and survive..
You CAN buy AGM golf cart batteries if you like, they do cost a bit more than a wet cell version and you do get a bit less capacity..
By the way, UPS batteries also tend to make for terrible deep discharging.. They are designed to be float charged all their life and will lose a lot of capacity quickly if charged/discharged a lot.. Typical life of a UPS battery which lives most of it's life in float charge is 2-3 years, get more than that you should celebrate.
On edit.. adding extra info.
Sams club 6V AGM golf cart battery
HERE20 amp hour rate:190
50% DOD gives you 95 Ahr, although 40% or less DOD will result in much longer life of the battery.
$100 per battery ($200 for 2 so you get 12V)
Sams club Wet cell golf cart battery
HERE20 amp hour rate:215
50% DOD gives you 107.5 Ahr
$84 per battery ($168 for 2 so you get 12V)
One should also note that many AGM battery manufacturers WILL list much lower discharge rates ON THE BATTERIES instead of the 20 Ahr rate. This skews the Ahr rating A LOT and makes the battery appear to have more capacity.