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Old 01-06-2017, 05:38   #1
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Engine battery need to be connected to house ground?

The alternator only charges the start battery. There are no other charge sources connected to the start battery. Do the house battery bank and start battery need to be ground together?
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Old 01-06-2017, 08:11   #2
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Re: Engine battery need to be connected to house ground?

Yes it does
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Old 01-06-2017, 10:37   #3
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Re: Engine battery need to be connected to house ground?

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Yes it does


Can you explain why?
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Old 01-06-2017, 10:46   #4
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Re: Engine battery need to be connected to house ground?

I would argue that they don't NEED to be. And, that "ground" is a poorly chosen and arguably misused word in the marine environment as well.

The starting battery NEEDS to be "grounded" to the engine block, or else directly to the starter and alternator in any case. The house bank does not need to be connected to the engine or the starter at all. It does not need to be connected to the starter battery at all. But it will make life more complicated if it is not connected to the alternator positive and ground, which is normally going to mean it is sharing a ground point with the starter battery.

Anyone who doesn't grasp that, really should get and read a couple of the inexpensive and well-recommended books on basic boat wiring and electrical systems, because not knowing about the basics can wind up costing you very dearly when something goes wrong. Firing questions on web forums will not get the comprehensive systems approach that the books have.
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Old 01-06-2017, 10:52   #5
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Re: Engine battery need to be connected to house ground?

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The alternator only charges the start battery. There are no other charge sources connected to the start battery. Do the house battery bank and start battery need to be ground together?
If you ever need to start using the house battery, its negative will need to be connected to the engine also. The end result is that both are connected to the same ground point. Also if you ever want to charge the house bank using the engine alternator, the house bank and start bank will need both their negtives connected to the engine.

so in a round-a-bout the answer is YES

But if under no circumstances ever will the engine charge the house bank, then "Technically" the starter battery could be completely isolated from the house with no common ground.
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Old 01-06-2017, 11:14   #6
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Re: Engine battery need to be connected to house ground?

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If you ever need to start using the house battery, its negative will need to be connected to the engine also. The end result is that both are connected to the same ground point. Also if you ever want to charge the house bank using the engine alternator, the house bank and start bank will need both their negtives connected to the engine.



so in a round-a-bout the answer is YES



But if under no circumstances ever will the engine charge the house bank, then "Technically" the starter battery could be completely isolated from the house with no common ground.

I want to keep the engine/alternator/ start battery isolated. If the start battery is dead, I have a long set of jumper cables that will reach the house bank.
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Old 03-06-2017, 09:59   #7
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Re: Engine battery need to be connected to house ground?

There is no reason your house bank "needs" to share a common ground with the engine.
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Old 09-06-2017, 00:13   #8
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Re: Engine battery need to be connected to house ground?

How do you will charge the house battery?

Pascal
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Old 09-06-2017, 03:26   #9
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Re: Engine battery need to be connected to house ground?

Greetings and welcome aboard the CF, Pascal.
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Old 09-06-2017, 04:10   #10
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Re: Engine battery need to be connected to house ground?

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How do you will charge the house battery?



Pascal


Primarily with solar and a wind generator. A Honda 2000 with a battery charger as backup.
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Old 09-06-2017, 08:04   #11
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Re: Engine battery need to be connected to house ground?

If the charge circuits are totally isolated, the ground circuit can be separated too.
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