I have a setup with Solar PV, battery, inverter, and AC load. Between the battery and inverter I have connected a custom circuit with DC power/energy/charge measurement, and a relay.

Problem is, circuit traces are limited to 4.5A, and the inverter charging current can go as high as 10A (and even if the amperage wasn't an issue, the circuit won't measure reverse current anyway).

To get around this, I am planning to connect two branches between the battery and inverter with diodes to control where current flows, like this:

enter image description here (Not shown is the MPPT solar charger, and the back-up AC source to the inverter).

Normally, when solar is charging the battery, current will flow through my measurement/control circuit, to the inverter, and on to the load. When I switch on the backup source to the inverter to charge the battery, the higher current will bypass my measurement/control circuit.

Assuming I can find the right diodes, is there anything wrong with this setup? Anything I'm not considering?

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    \$\begingroup\$ Have you considered leaving the trace uncovered and putting a good layer of solder all along it? \$\endgroup\$ – Ignacio Vazquez-Abrams Jul 12 '16 at 0:46
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    \$\begingroup\$ Or, for an even beefier trace, solder some copper wire on the top of the uncovered trace. Just make sure your vias/connectors can handle. \$\endgroup\$ – uint128_t Jul 12 '16 at 1:23
  • \$\begingroup\$ I hadn't thought of that, and it would work for quick and dirty... but I'd have to do it 20 times. Also, there'd be no way to tell if I'd done it right, until it failed. \$\endgroup\$ – LShaver Jul 12 '16 at 2:23
  • \$\begingroup\$ Just squeeze the paste out from a tube before reflow and let surface tension do the rest. \$\endgroup\$ – Ignacio Vazquez-Abrams Jul 12 '16 at 3:45
  • \$\begingroup\$ Let's say, for argument's sake, that's not possible... how does my diode scheme sound? \$\endgroup\$ – LShaver Jul 12 '16 at 4:30

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