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on my design, I am using two coin batteries in parallel and each battery has a Schottky diode in series to block the reverse current, in theory, it will avoid the higher potential battery "charge" the lower potential battery. enter image description here

But I am facing a higher current consumption when the two batteries are connected to the circuit, probably in reverse leak

Single Battery connected avg consumption 2.6uA

Two Batteries Connected Average Consumption 7.8uA

What should be the recommended to avoid that probable reverse current leak?

Change diodes, add a second diode in series (2 diodes per battery), replace diodes per an ideal diode IC?

update

diodes:MBR0520L The voltage at uC e.g: 3V it takes higher voltage between the two Batteries, usually exist few 1-15mV in the difference between each battery

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    \$\begingroup\$ Is the supply voltage different when you use two batteries instead of just one? Please measure the actual voltage at the microcontroller. Also, please provide a link to the manufacturer's datasheet for the diodes you are using. \$\endgroup\$ Commented Mar 25, 2019 at 17:43
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    \$\begingroup\$ Schottky diodes typically have much higher reverse leakage current than normal diodes. That low forward voltage drop and fast switching are nice, but come with that serious consequence. Before placing 2 in series, I would first look into changing to a regular diode with better reverse characteristics. \$\endgroup\$ Commented Mar 25, 2019 at 17:57
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    \$\begingroup\$ Using two Batteries like the setup in the image above, the power consumption increases 3-6 times depending on the uC load, then this could be related purely to the reverse leakage? \$\endgroup\$
    – Kirito-kun
    Commented Mar 25, 2019 at 18:08

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The reverse leakage current is not drawn into the datasheet diagrams for such low reverse voltages, but extrapolating the curve does indicate near 5uA of current could flow. For example a BAS40 would have 3 nanoamperes of reverse current at matching conditions so changing the schottky diode to a better might help.

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    \$\begingroup\$ I am able to replace to a BAS40 you are mentioning or some diode with lower reverse leakage current, what do you think about Ideal diodes IC? \$\endgroup\$
    – Kirito-kun
    Commented Mar 25, 2019 at 21:24
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    \$\begingroup\$ There is no such thing as an ideal diode. BAS40 is a good choice for you. A silicon diode would have even lower leakage than BAS40, if you can accept the higher forward voltage drop. \$\endgroup\$ Commented Nov 19, 2019 at 16:28
  • \$\begingroup\$ Can reverse leakage current damage battery? \$\endgroup\$ Commented Jan 26, 2022 at 20:06

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