05-07-2026, 09:18 AM
The 12.6V (or 6.3V) is nominal, like 1.4V. The Zinc carbon are about 1.6V dropping quickly to 1.5V with an endpoint of about 1V (for valves). Henct recommendation to use 1.35V on a power supply.
Older Lead Acid was 13.8V fully charged dropping to 11V (or 10V for greater risk of damage) at point where you should stop. Newer peaks at 14.2V so stops charging which would give off hydrogen and oxygen.
"as 4V and 2V heaters were commonplace in the heyday of lead-acid batteries, they're not quoted as 4.2V and 2.1V respectively. "
But those were never on charge while in use. The cell(s) were often charged at a cycle shop. The cell peaked at 2.3V on charge and quickly dropped to 2.2 on load. About 1.8V was end point, so 2V is the average.
Older Lead Acid was 13.8V fully charged dropping to 11V (or 10V for greater risk of damage) at point where you should stop. Newer peaks at 14.2V so stops charging which would give off hydrogen and oxygen.
"as 4V and 2V heaters were commonplace in the heyday of lead-acid batteries, they're not quoted as 4.2V and 2.1V respectively. "
But those were never on charge while in use. The cell(s) were often charged at a cycle shop. The cell peaked at 2.3V on charge and quickly dropped to 2.2 on load. About 1.8V was end point, so 2V is the average.
