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Hi Brent,
Your idea sounds good to me as it is similar to what I
will be using. I think you will have battery life issues. After calculating mine
I will have less life than I was hoping for and I will have 3 - 36 volt minkotas
and two banks of LARGE 6 volt batteries hooked in series.
Tha batteries that I will be using and are U3050S with 305
amp hours. They have 175 miniutes reserve capacity at a 75 amp draw and 675
minutes reserve capacity at 25 amp draw. At full power with all three thusters I
will be drawing 46 X 3 or 138 amps. I originally thought you could add the
reserve capacity of all batteries up, but my battery says the draw is the same
and you can add the voltage.
In my case with VERY rough interpolation I think one bank
of 6 of these large batteries will last me about 100 minutes with all three
thrusters at full power. Two at full power will give me about 145 minutes. and
one at full power will give me about 360 minutes. Then I will need to switch
banks.
I believe that your intended batteries are much smaller
and you might be better with smaller thrusters.
Before you buy thrusters you probably talk to someone
knowledgable in the battery area.
Best Regards,
Jim K
----- Original Message -----
Sent: Monday, December 08, 2008 11:22
PM
Subject: RE: [PSUBS-MAILIST] Lifting
K-250 Off Trailer the Hard Way
Hey
Frank,
I'll be waiting with
baited breath for the pictures. No snow yet, which is really weird. Last
year we got hammered. I was at one time thinking of monkeying with the
old housings, but the guys tell me they are worth big bucks on ebay, so I'm
planning on installing 36 volt Minnkota's like you are using. They are easier
to install and more stream lined. That way I can go really really fast.
I want to have two sets of
three 12 volt batteries set up in a series configuration to get 36 volts. This
way I can run the front two thrusters on one set of batteries, and the two new
rear thrusters on the other set. Alec told me that the 12 volt Minnkota's he
uses on the side of his K-250 are plenty good, so I was thinking about going
that route, but since I want to be able to switch which bank of batteries the
rear thruster or side thrusters run on, so if one bank is dead, I can just use
the other if any thruster issues come up. I've read that the Minnkota
power management system will let me use the 36 volt units, at slow speeds and
not pull any more power out of the batteries then needed, so I should be ok if
that is really the case. Also if I need a burst of speed I can put all four
thruster on full power at the same time. Does that sound
reasonable?
Regards,
Szybowski
From: ShellyDalg@aol.com
Date: Mon, 8 Dec 2008 18:38:08 -0500
Subject:
Re: [PSUBS-MAILIST] Lifting K-250 Off Trailer the Hard Way
To:
personal_submersibles@psubs.org
Hi Brent. Got snow yet? Your sub is looking good. I continue the FRP work
on mine and hope to get new pics up soon. Will you be using the old motor
housings or making new ones ( or Minnkotas)?
Keep up the restoration, and happy holidays. Frank
D.
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