[PSUBS-MAILIST] 48VDC generator

Tue Sep 11 15:39:02 EDT 2018

Brian,
it could be complicated. I was going to suggest having a switch to
switch from charging the batteries to running the motors, as you
may need to restrict the amps going in to the batteries depending
on their rating. However you may recall me posting about keeping
battery to controller wire length short to avoid large voltage
spikes in DC systems. You would have a very long wire length from
the generator to the motor controller carrying DC. A battery can act
like a large capacitor to absorb voltage spikes, so maybe it does
need to be incorporated in the system. It may be that you need an 
AC generator & a rectifier nearer the motor controller. Voltage spikes
from the motors could be a problem but I guess your motor controller
takes care of this. Some motor controllers have regenerative breaking
that feeds power from the motor as it slows down, back to the battery.
This is probably not a problem with a sub as you wouldn't get back
emf like you would from a car running down hill, however I test my
motors from a 48V rectifier & they advise to turn off regeneration on
my motor controllers in case it wrecks the rectifier. 
There should be a lot of information available as off grid people 
combine generators, battery banks & other forms of power generation.
Cheers Alan

> On 12/09/2018, at 5:17 AM, Brian Cox via Personal_Submersibles <personal_submersibles at psubs.org> wrote:
> 
> Hank,    I remember you talking about that,  I was thinking of getting a dedicated 48 vdc generator and hooking into the battery bank through the hatch and then disconnecting to submerge.
>  
> Brian
>  
> 
> 
> --- personal_submersibles at psubs.org wrote:
> 
> From: hank pronk via Personal_Submersibles <personal_submersibles at psubs.org>
> To: Brian Cox via Personal_Submersibles <personal_submersibles at psubs.org>
> Subject: Re: [PSUBS-MAILIST] 48VDC generator
> Date: Tue, 11 Sep 2018 11:34:06 +0000 (UTC)
> 
> Brian,
> That was my plan at one time also, I was going to use alternators with internal regulators.  It should work, but I am not sure how long the alternators will last if they are not sized correctly.
> Hank
> 
> On Monday, September 10, 2018, 11:20:59 PM MDT, Brian Cox via Personal_Submersibles <personal_submersibles at psubs.org> wrote:
> 
> 
> Hi All,
>                      Does anyone know what's involved in linking a 48 volt dc generator to ones 48 Volt drive system?   Is it as simple as connecting to the batteries?  If the generator senses a voltage draw then it engages, this is how most generators are set up .  Seems like there's got to be some sort of protection for the batteries so they don't see too much voltage.   I was thinking of having a 48 V dc generator in an inflatable secured to my deck and feeding my motors for surface transit.  Then once at the dive site leave the inflatable floating at the dive site. 
>  
> Brian
>  
>  
> _______________________________________________
> Personal_Submersibles mailing list
> Personal_Submersibles at psubs.org
> http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles
> _______________________________________________ Personal_Submersibles mailing list Personal_Submersibles at psubs.org http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles
> _______________________________________________
> 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/20180912/3859961b/attachment.html>