Here are 4 lead acid battery charging circuit projects, for 6V battery or 12V automotive, it is easy to use, with automatic charger control circuit [...]
This is the simple solar solar radio battery charger circuit. A solar cell radio used a 3V (or two 1.2V) Ni-Cad battery in it. The battery can not be removed. It use a mini jack socket for charging. Its quiet difficult to find such a voltage charger.
This stop current give battery, when Voltage of battery tall arrive at the level that load with full speed already ahead for protect something charger too much poor distilled dry…
Here is Universal nicd and nimh battery charger circuit. It use IC LM317T ( Hot IC) Control Current less 300mA, Size battery 2.4V,4.8V,9.6V. Low cost circuit
This is IC 7805 constant current circuit for battery charger, It is advantage that we have IC- 5-volts 1A positive voltage regulator as current regulation