Almost all 24V power systems in
trucks, 4WDs, RVs, boats, etc, employ two series-connected 12V
lead-acid batteries. The charging system can only maintain the sum of
the individual battery voltages. If one battery is failing, this
circuit will light a LED. Hence impending battery problems can be
forecast. The circuit works by detecting a voltage difference between
the two series connected 12V batteries. Idle current is low enough to
allow the unit to be permanently left across the batteries.
Battery Equality Monitor Circuit Diagram
Battery Equality Monitor Circuit Diagram
Parts:
R1 = 2.K
R2 = 4.7K
R3 = 39K
R4 = 39K
R5 = 1.5K
R6 = 1.5K
Q1 = BC547
Q2 = BC547
Q3 = BC557
D1 = 3mm Red LED
D2 = 3mm GreenLED
B1 = DC 12 Volt
B2 = DC 12 Volt