[cgtech]

I see the value of the proof offered by a hydrometer (and I have a refractometer that I rarely need). I really feel that a volt meter will tell you everything you need to know if the measurements are taken correctly, with reasonable measuring equipment. The specific gravity tells you when a cell in a battery is bad, or out of balance, so you can do what? Change that individual cell out of that battery? They don't come out individually at the dealer/repair level of service. Yamaha & Ezgo seem to at least partly agree with this, they only require specific gravity readings for battery warranty under few circumstances. Like unusual failures, and very young batteries, but the requirements are not well defined (fill out this form, we will get back to you if we want SG readings). Yamaha is a little different about fleets, they want SG readings for those, because they want you to grade all batteries​ (A, B, C, D) and group like batteries together in carts. I agree about the "Lester Discharge Tester", anyone who will be regularly servicing carts, or calls themselves a golf cart shop needs one. If I were operating a fleet, I would want one too.