Hard rubber container
Battery case made from hard rubber (Ebonite). The lid is sealed with asphalt. Still used for special applications and in third world countries,
where batteries still are repaired instead of replaced.

Heat sealing machine
Machine with hot plates, welds the >> cover onto the battery case.

Heavy Duty
Battery type with an above-standard cycle stability and shock resistance. Applications: Commercial vehicles, construction and farm machinery. Often manufactured
with a glass mat laminated separator.

High current charging
Charging with a current strength greater than 1C.

High current discharging
Discharging with a current strength greater than 5C.

High rate discharge tester
The battery is discharged with a very high current for a very short time. The tester can find out, whether the battery has the necessary cold cranking capacity.

High volt leakage tester
With this test it is possible to detect very small holes in the battery case and in the welding area between the cover and the case, used voltage up to 12 kV.

Hole punching machine
For punching holes in the walls of the >> battery case. Necessary for the intercell connection.

Hydrometer
A floating instrument used to determine the specific gravity of liquids.