Will the below circuit act as a one-way current restrictor to allow 100A to flow out of the battery, but limit charging current to 10A into the battery from the alternator?

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    \$\begingroup\$ .Your circuit will make lots of heat and will charge the battery very slowly \$\endgroup\$ – Autistic Jan 24 '19 at 0:21
  • \$\begingroup\$ It will limit the charging current to 10A only if your alternator is a 24V source. \$\endgroup\$ – user2233709 Jan 24 '19 at 0:24
  • \$\begingroup\$ In short: no, that won't work the way you think. Also, you should really explain what you need that specific current limiting for. Sounds dangerous. \$\endgroup\$ – Marcus Müller Jan 24 '19 at 0:29
  • \$\begingroup\$ If you're outputting 100A, use a diode rated for at least 150A. \$\endgroup\$ – Hearth Jan 24 '19 at 0:49
  • \$\begingroup\$ If this is a car with a regular high CCA car battery, you may find this question worth a read before you clarify your question. \$\endgroup\$ – K H Jan 24 '19 at 1:24

No, the only thing limiting the current charging the battery is the 100A fuse, put a 10A fuse in series with the resistor, like this:


simulate this circuit – Schematic created using CircuitLab

This way, if current tries to flow out of the battery, discharging it, it can go through the diode, skipping the 10A fuse, and only being limited by the 100A one, however, when charging it, it can go through both fuses, so below 10A, the battery will charge, above 10A, the 10A fuse will blow, above 100A, maybe both fuses blow, maybe just the 100A one, depends on your luck and on how fast they blow.

Also you should probably use a slightly higher current value for the diode, like 150A, just to give the margin of error.

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    \$\begingroup\$ I suspect this technically answers the question, but not necessarily in the way the OP intended. \$\endgroup\$ – Simon B Nov 26 '19 at 8:21

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