better cycling and depth of discharge over the wet or gell batteries. While most wet batteries are supposed to only go to about 50% depth of discharge, the AGM's are able to go to about 20% depth of discharge without harming them PROVIDED that you don't overcharge them at too high a voltage on their return. What does this mean in numbers? If you have a Golf Cart battery that is 220 amp/hours for both the wet and the AGM, then the AGM would be able to have 176 ah of useful capacity (220 X .80) vs. the wet battery at 110 amp/hours
AGM's need no watering and will receive a charge faster than wet batteries or Gell batteries. How much faster?
AGM will charge over twice as fast. Throw Peukert's law out the
window: the physical compression of the plates in the cell compartment, when coupled with the better quality of materials in an AGM give it far less internal resistance than the other types. Practically speaking this
means less time to recharge your batteries while underway.
AGM's can be mounted in any position, require no room for venting and therefore can be installed in living quarter sections of your boat. This can
be especially important if you already have a cramped space in mind for your batteries. Also, because of the low internal resistance of the batteries, they were tested by the Coast Guard for their potential for
explosion and they passed with flying colors (excuse the pun) by not exploding when heated to 200 degrees f., then dead shorted! So these are some amazing batteries.
AGM's also are virtually maintenance
free: although everyone should visually check the terminals and general condition (for swelling, corrosion, black post, or high temperature) of a battery at least every six months. How long will they last? Who knows?
"Batteries don't die, their owners kill them."
The AGM has a design life of 10 -12 years.
Trojan 6v battery design life 3 – 5 years
Price is pretty stiff when compared with the wet lead acid batteries--generally by 2 times. This difference begins to fade if any of the above items listed are important to you: cramped space, no maintenance, difficult mounting, rapid recharge, explosion-proof and non-gassing.
Wet Lead Acid Battery Con's: Slower to recharge than AGM, require maintenance more often, and don't cycle as deeply as the AGM batteries.
The wet cells need to have space and volume around them to allow the flow, cool and allow transfer of ions and acid back and forth in the liquid solution.
You’ll have something "cooler" than a regular battery: you will have the latest, greatest battery.
NO hassle of standing on your head to fill 'em with distilled water, sitting in or flicking acid on yourself.
¥ Faster recharge time, less engine or generator run time, safety from explosion, and more storage options.
Longer design life
There! You are, the reasons to buy an AGM battery: