18-03-2019, 08:48 PM
(This post was last modified: 18-03-2019, 08:58 PM by Bob Culver.)
What constitutes a charge? As batteries age the ah capacity effectively diminishes. Even so if genuinely fully charged should hold better than that. Usually one cell fails before others, recharging then overcharges the rest reducing their lives. If you can draw acid, a hydrometer usually reveals odd cells. Or great differences in gassing stages.
Regular deep discharging is very damaging (Gaurantees do not apply to vehicles without regualtors.) In a past life I had contact with telephone cable jointers. Once a lead wiped joint was open they worked around the clock to complete. Used batteries for lighting, regularly flattening them. The batteries had an extreme short life.
A modest charge rate in the car backed by a good float charger seems the ideal. Perhaps with a traditonal 4 or 5 amp for occassions when significantly flattened, as prolonged charging from low at low rate is not ecommended..
The advent of more or less sealed Low Maintencace batteries has complicated things. Sources state not supposed to be charged beyond 14.2/7.1 at reasonable rate, yet modern regulators apparently operate at 14.6. These batteries hold charge with almost no loss. Ironically, in modrn cars the diodes and computer etc drain significantly!
(Even with traditonal batteries tolerant of overcharging, I dont know how owners of other old cars get along. Ford 8s for example have no voltage regulator and no Summer charge. must hammer batteries on trips.)
Regular deep discharging is very damaging (Gaurantees do not apply to vehicles without regualtors.) In a past life I had contact with telephone cable jointers. Once a lead wiped joint was open they worked around the clock to complete. Used batteries for lighting, regularly flattening them. The batteries had an extreme short life.
A modest charge rate in the car backed by a good float charger seems the ideal. Perhaps with a traditonal 4 or 5 amp for occassions when significantly flattened, as prolonged charging from low at low rate is not ecommended..
The advent of more or less sealed Low Maintencace batteries has complicated things. Sources state not supposed to be charged beyond 14.2/7.1 at reasonable rate, yet modern regulators apparently operate at 14.6. These batteries hold charge with almost no loss. Ironically, in modrn cars the diodes and computer etc drain significantly!
(Even with traditonal batteries tolerant of overcharging, I dont know how owners of other old cars get along. Ford 8s for example have no voltage regulator and no Summer charge. must hammer batteries on trips.)