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Old 06-26-2017, 10:53 PM   #12
dhays
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City: Gig Harbor
Vessel Name: Kinship
Vessel Model: North Pacific 43
Join Date: May 2015
Posts: 9,046
Quote:
Originally Posted by menzies View Post
My thinking, what percentage of boat time are you using thrusters and windlass, and even davit?

Why dedicate batteries to those causes?

Dave, what pitfalls do you foresee, other than depleted batteries not allowing you to run those items (again these seem to be things that you would use when the engine is running)?

There are several issues.

-To combine the two banks properly I would need to use two rather long parallel links between the batteries. This would certainly be possible but would not be ideal

- The thruster bank are expensive batteries in good shape but are different than the new house batteries I am adding. This would be OK but it makes a lot of purists really uncomfortable to combine different age, size, and manufacturer of batteries.

- I would need to come up with another way to measure SOC for the batteries. The SOC meter I have maxes out at 1000 Ah. The combined bank would be 1190 Ah. I could install a Balmar SmartGuage but that would require a lot of very long wiring runs as well as cutting new holes in my Pilothouse dash. I'm lazy so that doesn't sound fun.

- I have Vetus 95kg thrusters. They recommend a battery bank of 165-286Ah. They specifically warn against using a battery bank that is significantly larger than recommended because that reduces the maximum operating time. They also warn that if the Ah capacity of the bank is 5x or greater than the recommended size that the increase in thrust can actually damage the connection between shaft and motor or shaft and propeller. 1180 is about 5x the recommended Ah capacity range they recommend.

- Can my alternator handle sending that much current to that large a bank with a controller?

Those are just some of my thoughts.
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Regards,

Dave
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