RE: [PSUBS-MAILIST] More Batteries....power configuration?

["Alec Smyth" <Asmyth@changepoint.com>]

Agreed. I'm using a pair of 24V trolling motors that draw 45 amps each, with batteries in the hull. If anyone is using a similar rig, you might find it useful to know that Subconn offers a penetrator that is exactly right. It has 4 conductors rated at 50 amps each. Here's the link: 

http://www.subconn.com/subconn.asp?page=pow04

This violates ABS rules (the same penetrator should not carry both polarities) but I suspect the reason for the rule is that commercial subs use much higher voltages, and I feel safe knowing I have only 24V across insulation designed to withstand 600V.

rgds,

Alec

-----Original Message-----
From:	Dan H. [mailto:JMachine@adelphia.net]
Sent:	Mon 4/28/2003 10:22 PM
To:	personal_submersibles@psubs.org
Cc:	
Subject:	Re: [PSUBS-MAILIST] More Batteries....power configuration?

Sounds right Alec,

Also components like relays and speed controllers are larger and more
expensive as the current goes up.  There's really isn't any more danger from
electrocution from 36 volts then there is from 12.  If you carry it farther
and series batteries up to 72 or 120 volts then you could have a problem if
things gets wet. Especially with salt water.

There is an upside to 12 volts though.  You can find a lot of components
available in any auto or boat shop.

Dan H.

----- Original Message -----
From: "Alec Smyth" <Asmyth@changepoint.com>
To: <personal_submersibles@psubs.org>
Sent: Monday, April 28, 2003 4:31 PM
Subject: RE: [PSUBS-MAILIST] More Batteries....power configuration?


> I'm not an expert on this, but here's my understanding. If I'm off,
> somebody please correct me.
>
> Choosing series or parallel does not change the amount of energy stored
> in your batteries, so in principle there is no difference in range,
> speed, or duration. However the currents carried will change
> significantly, as Amps * Volts remains constant.
>
> Therefore a series battery bank (i.e. higher voltage) lets you use
> smaller conductors. That means cheaper cable, and saved weight. If going
> through the hull, the conductors on a penetrator might not be able to
> carry the currents you would need at low voltages. The downside of
> series arrangements is of course that you have to pay more attention to
> electrical insulation, as you get into ranges that are a potential
> health hazard.
>
> Rgds,
>
> Alec
>
>
>
> -----Original Message-----
> From: steve [mailto:steve@kobol.worldonline.co.uk]
> Sent: Monday, April 28, 2003 4:22 PM
> To: personal_submersibles@psubs.org
> Subject: Re: [PSUBS-MAILIST] More Batteries....power configuration?
>
> Hi All
> i have a question, how do you decide how the power systems are
> configured on
> a sub?
> I was wondering if anyone can tell me why there are different voltages
> used
> and what benefits / disadvantages there are.
> for instance, say my sub has 10 x 12v 110AHr batteries as its main power
> source, if they were all connected in parallel, i potentially have over
> 1000AHrs to play with.
> Why would i want to connect the batteries to give a higher voltage at a
> lower current capacity?  does a motor running at 48v work more
> efficiently
> than a motor running at 12v or is it something more technical than that?
>
> to put it simply, if most (or all) of the on-board systems will run on
> 12v
> is there any benefit in running thrusters at a higher voltage?
>
> Steve Bosworth
> UK
>
> ----- Original Message -----
> From: "Garry Muir" <garry.muir4@virgin.net>
> To: <personal_submersibles@psubs.org>
> Sent: Monday, April 28, 2003 9:23 PM
> Subject: [PSUBS-MAILIST] More Batteries
>
>
> > Hi Folks
> >
> > Try this URL for battery specs and US prices has most makes including
> > Optima
> >
> > www.batteryweb.com/manufac.cfm
> >
> >
> > Reagrds, Garry
> >
>
>

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