I have the dual battery arrangement shown in the attached diagram in my 50cc RC plane. B1 and B2 are Lithium Iron Phosphate (LiFe) batteries. The third circuit shown in the diagram is a little battery sharing circuit configured on a piece of stripboard.
The diodes prevent current flowing back into the batteries should one fail. The LEDs are just reminders to shut the switches OFF. Battery voltage is 6.6 volts.
So here is what’s happening:
When SW1 is closed, I read 6.36 volts at TP1 and 1.65 volts at TP3
When SW2 is closed I read 6.43 volts at TP1 and 1.65 volts at TP2
When BOTH switches are closed I read 6.53 volts at TP1 and 6.6 volts at TP2 and TP3. So far so good.
Now here is the really odd thing – when both switches are open I read 0.16 volts at TP1, even when the batteries are disconnected!
I have two questions: Why am I reading voltage (1.65V) at TP2 and TP3 when only one battery is on line?
The second, and most puzzling question is why am I reading 0.16 volts at TP1 in the OFF state? I have used two different DMM and get the same result. Any ideas?
The diodes prevent current flowing back into the batteries should one fail. The LEDs are just reminders to shut the switches OFF. Battery voltage is 6.6 volts.
So here is what’s happening:
When SW1 is closed, I read 6.36 volts at TP1 and 1.65 volts at TP3
When SW2 is closed I read 6.43 volts at TP1 and 1.65 volts at TP2
When BOTH switches are closed I read 6.53 volts at TP1 and 6.6 volts at TP2 and TP3. So far so good.
Now here is the really odd thing – when both switches are open I read 0.16 volts at TP1, even when the batteries are disconnected!
I have two questions: Why am I reading voltage (1.65V) at TP2 and TP3 when only one battery is on line?
The second, and most puzzling question is why am I reading 0.16 volts at TP1 in the OFF state? I have used two different DMM and get the same result. Any ideas?