Hi,
I have some differential amplifier for hi-side current sensing that did'nt work, the output is always sitting on 3.8V whatever the condition is (no current/current flow), the one that did'nt work is the bat and load side (same symptoms), the diagram is on the attachment, i used 10k/220k for 22 gain for both amp (bat and load) instead of what is showed on the diagram, the amp is powered with 5V single supply, i have tried to replace the IC with other LM358, but the problem remains the same.
However, i had differential amplifier with 47 gain (1k/47k) that did work, it powered with 5V too, the diagram is attached too.
What probably is the problem?
NOTE : The bat diff amp and load diff amp is on different IC, not like what is showed on diagram.