[RE-wrenches] unique battery bank design question

[Jason Szumlanski]

Dan,

 

What kind of efficiency level (%) can you get out of a DC-DC supply on a
small load, say <5A @ 12V with a 48V->12V converter? Is the efficiency
level highly variable depending on load as a percentage of the
converter's maximum capacity, or is it pretty constant?

 

I run into this once in a while, so this piece of information would help
me make some better decisions.

 

Thanks,

 

Jason Szumlanski

Fafco Solar 

 

 

From: re-wrenches-bounces at lists.re-wrenches.org
[mailto:re-wrenches-bounces at lists.re-wrenches.org] On Behalf Of Exeltech
Sent: Thursday, September 01, 2011 3:58 PM
To: RE-wrenches
Subject: Re: [RE-wrenches] unique battery bank design question

 

Mac,

Don't tap the battery.  Bad idea.  Uneven loading = unequal
charge/discharge, which leads to shortened battery life and other
troubles.

Better idea:  If you know the maximum load current, use high-efficiency
DC-DC supplies of adequate current and other ratings to step 48V down to
12 or 24V.


Dan
Sr. Engineer
Exeltech


--- On Thu, 9/1/11, mac Lewis <maclewis1 at gmail.com> wrote:


From: mac Lewis <maclewis1 at gmail.com>
Subject: [RE-wrenches] unique battery bank design question
To: RE-wrenches at lists.re-wrenches.org
Date: Thursday, September 1, 2011, 2:52 PM

Hello wrenches,

 

I have a battery bank questions.  I have an Oil & Gas client interested
in setting up an off-grid control system that has a various DC loads at
12VDC, 24 VDC and 48 VDC.  My thought is to build a 48 V battery bank
and tap off the bank at various points to create a 12V bus, 24V bus and
48V bus.  I am a bit concerned about unequal loading of the batteries.
Has anyone dealt with something like this that would like to share some
insight?

 

Thanks


 

-- 

 

Mac Lewis

 

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