I just ran across something that may be useful for folks replacing/upgrading batteries:
Convert Reserve Capacity to Amp Hours (http://www.ehow.com/how_8681870_convert-reserve-capacity-amp-hours.html)
It seems more battery specs list Reserve Capacity now instead of the old familiar Amp-Hours. For example for the NAPA 8D Gel Battery (https://www.napaonline.com/napa/en/p/NBP8275/NBP8275):
475 Reserve Capacity (minutes) x 60 = 28,500 seconds x 25 amps = 712,500 coulombs of charge.
712,500 coulombs / 3600 coulombs/amp-hour = 198 amp-hours.
Or, just multiply the Reserve Capacity by 0.4167 to convert to Amp-Hours.
WHAT?
I thought it was amp-hrs per pound. About 1.5 I think. Fun with math! 🤓