A link to the site to see what the heck is going on?
317 ampere hours is quite normal for a flooded L-16
Something to chew on....
In a history of several thousand alike flooded batteries those that had more active plate area per quantity of acid had a higher warranty percentage factor. And the difference was not insignificant. This included six or seven different manufacturers. It's a shame I have no idea if this is true with absorbed glass mat.