Can DC circuit breakers be used in reverse?

Kwik Decision

Kwik Decision

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We don't have a "plumbed in" battery charger on the boat, but do carry a cheap and cheerful car charger, which gets used occasionally. Rather than connecting the charger direct to the batteries with croc clips, which involves crawling down the quarter berth, it would be much easier to put a plug on the cable, and plug it into the socket used for charging mobiles etc. This socket is protected by a circuit breaker, hence my question, can DC circuit breakers be used in reverse? If it were a good old fashioned fuse, no problem..... Oh, the charger is rated 6 A, and the circuit breaker is 15 A.
Cheers
Andy
 
Most work by thermal rise with the trip set to operate at a temperature corresponding to the designed current rating. They don't have diodes so should work in either direction. Simple thermal trips such as the Eta 1610 range I am fitting can be fitted either way around.
 
andrewbroadbent said:
We don't have a "plumbed in" battery charger on the boat, but do carry a cheap and cheerful car charger, which gets used occasionally. Rather than connecting the charger direct to the batteries with croc clips, which involves crawling down the quarter berth, it would be much easier to put a plug on the cable, and plug it into the socket used for charging mobiles etc. This socket is protected by a circuit breaker, hence my question, can DC circuit breakers be used in reverse? If it were a good old fashioned fuse, no problem..... Oh, the charger is rated 6 A, and the circuit breaker is 15 A.
Cheers
Andy
Click to expand...

I have done this for many years and it works.
 
Can the ('cigarette lighter'?) socket cope with 6A without over heating? I tried the same with my little genny, 12v output, hot!
Secondly, I'm sure you have factored in the losses when charging via some length of thin-ish cable?
Thirdly Do you have a splitter or 1-2-both switch you can get at? croc clips or permanent tails there would allow you access to starter type cabling.
N
 
NickRobinson said:
Can the ('cigarette lighter'?) socket cope with 6A without over heating? I tried the same with my little genny, 12v output, hot!
Secondly, I'm sure you have factored in the losses when charging via some length of thin-ish cable?
Thirdly Do you have a splitter or 1-2-both switch you can get at? croc clips or permanent tails there would allow you access to starter type cabling.
N
Click to expand...

My 'lighter sockets' are the 'marine' type ( http://www.ecs-marine-equipment.co.uk/marine-equipment/sutars-recessed-socket-item-2411.html ) and rated at 16 amps. I have used at least 27 amp cable if not bigger and 15 amp fuses. So far no problems.
 
Should be fine if circuit breaker is thermal type, which it probably is. Only initial reservation was quenching any arc (often uses blow out coil), but at 12 volts, not enough to sustain an arc, so that's OK too. Plus, any short circuit on charger side of the breaker will limit battery current in the design direction anyway, and charger is harly likely to be able to produce enough fault current to be of concern, go for it.
 
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