Thread: AGM Batteries

They would work but not sure how they would last. I’d sure take my time and look for the best deal I could find on marine or RV battery.

For the trolling motor you want a battery designed for "deep cycle." The ones designed for golf carts are usually the best.

AGM batteries can be used to about 50% power before charging. You don't want to drain it completely as it will lessen the life of the battery. LIFEPO4 Lithium Batteries and be run down to less than 5% before charging without hurting the charging cycles. If you can afford lithium for your TM it would be best but AGM sealed batteries work fine. Just watch the charge level while using.

Originally Posted by SlabSlider

AGM batteries can be used to about 50% power before charging. You don't want to drain it completely as it will lessen the life of the battery. LIFEPO4 Lithium Batteries and be run down to less than 5% before charging without hurting the charging cycles. If you can afford lithium for your TM it would be best but AGM sealed batteries work fine. Just watch the charge level while using.

I have an AGM and that is contrary to published data. The AGM has a lower cycle rate than flooded cell and charges much faster.


The following excerpt is from this link: Absorbent Glass Mat (AGM) Battery Information - Battery University
There are several other sources that state the same info. I did a good bit or research before I bought mine.

Learn what differentiate AGM from other lead acid battery types

AGM technology became popular in the early 1980s as a sealed lead acid battery for military aircraft, vehicles and UPS to reduce weight and improve reliability. The sulfuric acid is absorbed by a very fine fiberglass mat, making the battery spill-proof. This enables shipment without hazardous material restrictions. The plates can be made flat to resemble a standard flooded lead acid pack in a rectangular case; they can also be wound into a cylindrical cell.

AGM has very low internal resistance, is capable to deliver high currents on demand and offers a relatively long service life, even when deep cycled. AGM is maintenance free, provides good electrical reliability and is lighter than the flooded lead acid type. While regular lead acid batteries need a topping charge every six months to prevent the buildup of sulfation, AGM batteries are less prone to sulfation and can sit in storage for longer before a charge becomes necessary. The battery stands up well to low temperatures and has a low self-discharge.
The leading advantages of AGM are a charge that is up to five times faster than the flooded version, and the ability to deep cycle. AGM offers a depth-of-discharge of 80 percent; the flooded, on the other hand, is specified at 50 percent DoD to attain the same cycle life. The negatives are slightly lower specific energy and higher manufacturing costs than the flooded, but cheaper than the gel battery.

From Searay post,

""" While regular lead acid batteries need a topping charge every six months to prevent the buildup of sulfation,"""

Is this for batteries that are in a more or less standby situation or is this necessary for batteries that are used and recharged at least once a week???