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current limiting circuit vs. fuse protection

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robismyname

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Im working on an application where I am charging a 12V battery with a generator that has 12VDC output. In order for the generator to charge the battery I need to close the contacts on my relay board using a signal from my microcontroller.

The relay is rated for 16A at 24VDC. the generator dc output is rated at 12v, 100w, 8.3 A. Do I need any type of protection in front of my relay even though the relay current rating is double the current from the generator? The relay board vendor recommends a fuse but i dont see why if the current from my generator is no where close to the relay current capacity.

If I do need protection would I use a current limiting circuit like the one I attached or is a simple fuse good enough?


https://www.centralsemi.com/PDFs/selection/leaded/CLD_HighCurrent.pdf
https://www.centralsemi.com/PDFs/other/ec051semiconductora.pdf

Please advise someone.
 
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You need to protect the generator - relay contacts - battery loop because of a possible short circuit between cables or in the battery -- this could overload the generator and the relay contacts (in case of a short circuit, the generator could deliver more than the rated 16A). Use a simple fuse!
 

I will also recomment to use fuse in series with the relay contact not only bcz it will prvent short circuit protection....but if you chose proper value it may also give you over current protection too.....
 

A 12V generator will not charge a 12V battery. The source voltage must be higher than the battery voltage, e.g. about 14V for a lead-acid battery.
 

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