[RE-wrenches] unique battery bank design question

[mac Lewis]

Glad I asked!  Do these converters have a decent expected lifetime?  If
anyone has any good DC-DC converters to peddle, please contact me off list.

Thanks for the help.

On Thu, Sep 1, 2011 at 2:48 PM, Jason Szumlanski <Jason at fafcosolar.com>wrote:

> 1a x 12V x 24hrs = 288 watt-hours on a 48,000 watt-hour battery. My math
> shows 0.6% of the nominal capacity. And that assumes there is no
> charging source present.
>
> That being said, I would agree that avoiding it altogether is the wise
> decision, but there has to be a level at which the tapped load is
> inconsequential. I'm just curious what that level is!
>
> Jason Szumlanski
> Fafco Solar
>
>
> -----Original Message-----
> From: re-wrenches-bounces at lists.re-wrenches.org
> [mailto:re-wrenches-bounces at lists.re-wrenches.org] On Behalf Of Hugh
> Sent: Thursday, September 01, 2011 4:21 PM
> To: RE-wrenches
> Subject: Re: [RE-wrenches] unique battery bank design question
>
> At 15:57 -0400 1/9/11, Jason Szumlanski wrote:
>
> >  A 1A @ 12V fan on a 1000aH @48V battery bank can't make any real
> >difference. Correct me if I am wrong!
> >
>
> Yes that is wrong, because after 4 days you have removed 10% of the
> nominal capacity or about 20% of the usable capacity.
>
> Tapping off batteries is bad practice as universally agreed.  One way
> to mitigate it could be to use separate shunt regulators (diversion
> load controllers) for each 12-volt portion.  This would probably be a
> healthy feature for 'balancing' any 48 volt battery and would
> possibly rescue a tapped battery, given enough surplus energy
> availability (which is usually the key thing for battery health).
>
> Just a thought.
>
> The snag is the cost.  ho hum.
> --
> Hugh Piggott
>
> Scoraig
> http://www.scoraigwind.co.uk
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-- 



Mac Lewis

*

"Yo solo sé que no sé nada." -Sócrates
*
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