[PSUBS-MAILIST] batteries

[Rick Patton via Personal_Submersibles]

Sean,
I have about 8' from battery to selector switch and then about 10' from
switch to pos buss so around 18'.

On Sun, Oct 29, 2017 at 12:21 AM, Sean T. Stevenson via
Personal_Submersibles <personal_submersibles at psubs.org> wrote:

> Rick, what is the length of the wire run? Sizing a cable appropriately
> involves keeping the overall voltage drop in the circuit to 2.5% - 3% of
> the nominal source value, maximum, and of course, lower is better. This is
> dependent on length, so for a longer run you need a bigger cable, etc.
> There are calculators available for this purpose. One of my favourites is
> an Android app called "ElectroDroid". There are also online tools.
>
> Sean
>
>
> Sent from ProtonMail mobile
>
>
>
> -------- Original Message --------
>
> On Oct 28, 2017, 13:27, Rick Patton via Personal_Submersibles <
> personal_submersibles at psubs.org> wrote:
>
>
> I am trying to size my wire for the 36v side from where the power comes
> into the sub to selector switch to hot buss bar and was wondering if that
> was something that someone could answer. Also I was told by Minn-Kota that
> they recommend group 27 marine batteries.
> I have a couple of deep cycle (marine batteries) on my boat and they are
> 550 cca and 125 amps reserve capacity.
> My plan is to run all three Minn-kota thrusters off of one side at a time
> and their max draw is 46 amps max so there is 138 amps if all three
> thrusters are wide open. I doubt I would ever have all three maxed for more
> than short spurts but want to be repaired for the worst case scenario like
> if I am bucking a strong current.
> I also will be running 6 outside LED lights off the same bank and though I
> can dim them and selectively use them, all on at max would be about a 16.6
> amp draw as well. Now most of the time I will be using the thrusters at
> minimal draw and not all 3 at the same time and the 6 lights will probably
> never all be on at the same time.
> If everything was wide open, I would be pulling about 155 amps from a bank
> that has a reserve capacity of 125 so it would deplete the bank rather fast
> and may even damage the batteries due to a quick drain? So,,, first
> question...would 2 OTT wire be sufficient from battery source to bus bar as
> long as I am not running full tilt on everythig and second... since I have
> to stick with a lead acid system due to design, can I get a group 27
> battery that can deliver much more than the 125 amps I have on my boat?
> I also have the option of putting the battery selector switch on both
> banks if I have to but would rather deplete one bank at a time if can.
> Comments appreciated.
> Rick
>
>
> _______________________________________________
> Personal_Submersibles mailing list
> Personal_Submersibles at psubs.org
> http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://www.whoweb.com/pipermail/personal_submersibles/attachments/20171029/839b70c8/attachment.html>