Primary

Alkaline

Lead-acid

Edison

Hydrogen

Methane

Oxygen

Carbon dioxide

1.25 V

1.50 V

1.00 V

2.00 V

lower e.m.f.

smaller quantity of electrolyte

higher internal resistance

compactness of the cell

its charge efficiency is low

it takes comparatively long time to charge a battery fully

in it, per cell charging voltage should not exceed 2.3 to 2.5 volts.

all the three problems stated above