@swoop

Here is some info on battery ratings that might help you.

"AH (Ampere-Hour) Ratings
6 Hour vs. 20 Hour Ratings:
Rating a battery over a longer time period always means a lower current draw over a longer period of time. The lower the continuous amperage during discharge, the more efficient the battery becomes. The opposite is true when the continuous current draw is increased.

· Forklift applications usually use the 6hr rating."
FYI in Japan and I believe Europe too industrial batteries are rated at a 5 hour rate.

That rating is when the battery is continuously discharge over a 5 or 6 hour period. In actuality a lift truck is not continuously discharged and the time they are used in a single 8 hour shift is much less than 8 hours probably about 3.5 hour meters hour on average high ball operation like break bulk operations (high usage) at ABF, Road Way, etc are about 5.5 hours per 8 hour work shift.
Here is a link for more info.
gbindustrialbattery(dot)com/Battery_Options/AH_Ratings(dot)html - do teh remove the (dot) an replace it with a. close all gaps