battery selector

[eplanet]

hello
i want 3 or 4 battery sequent work. if no1 battery will be end no2 start and no2 will be end no3 start and .... do u have any idea?

 

[audioguru2]

You can make a complicated circuit that measures the battery voltage and if it gets low then the circuit replaces the battery with a new one, 4 times.

Or you can simply connect 4 batteries in parallel. They will last 4 times as long as one battery, the same as sequencing them.