Sorry so long. Thought this would be a good share. Email received from XS Power:
Thanks for contacting us regarding the proper way to charge sealed lead acid (AGM) type batteries like the ones we produce. Unlike conventional lead acid batteries, AGM batteries are completely sealed, meaning that all of the gas and electrolyte is safely stored inside the battery. In order to keep AGM batteries in good health, and to maximize their performance and life expectancy, it is important to properly charge and maintain them.
Leaving a battery (conventional or sealed) in a low state of charge over a long period of time is bad for the battery because it allows the electrolyte the opportunity to crystalize, or dry out directly on the surface of the lead plates of the battery. Once this material (lead sulfate) is produced, the battery loses its capacity and performance, and the charge acceptance of the battery is greatly reduced.
More importantly is making sure that when the battery is being recharged, either in a vehicle, or with a battery charger, that the charging voltage is not too high, relative to the ambient temperature around the battery. On a daily basis, when customers ask us what voltage to charge their battery, our standard response is 14.4V, but as you can see in the illustration below, the optimal charging voltage really depends on how and where the battery is being used. For installations where the temp exceeds the limits of our chart, we recommend XS Power PN 500, which is our heat reflecting wrap that helps reflect some of the heat in high temp applications.
For your alternator customers who chose to disregard our charging voltage recommendations, it is likely they will start to experience problems within the first year of ownership of their AGM battery, and none of the AGM battery companies offer warranty against improper charging, so it would be an expensive lesson to learn if they chose to charge outside of the factory recommendations.
If you have any questions, or would like any further info, please do not hesitate to let us know!
Technical Service Team
XS POWER
2847 John Deere Dr.
Suite 102
Knoxville, TN 37917
tel: 865.688.5953
fax: 865.281.9844
(Here is our info on how to properly hook up an XS Power https://www.iraggialternator.com/xs-power-vcm-hook-up)