That's right, absolutely NAC. Electrical question

[Paul Caouette]

Most Marine batteries are deep cycle. 

Sent from my iPhone

On May 30, 2013, at 8:55 PM, Huw Powell <audi at humanspeakers.com> wrote:

> The only problem with that is that "starter batteries" are not designed for "deep cycle" needs, which this is.
> 
> - Huw
> 
> On 5/30/2013 7:37 PM, Tony Hoffman wrote:
>> Or add a second battery, wired in series to the stock one for the purpose
>> you need and pull from the two of them for 24V, and plenty of amperage so
>> it won't go dead in short demand. This is exactly how older Cummins were
>> wired, 24V starter and alt, 12V everything else.
>> 
>> HTH,
>> Tony
>> 
>> On Thu, May 30, 2013 at 3:45 PM, Richard J Lebens <rick-l at rocketmail.com>wrote:
>> 
>>> Start out in a perfect world - 100% efficiency.  The rated output of the
>>> supply is 24 @ 3.75 Amps which works out to 90 Watts.  (It probably does
>>> not run at it's rated output)  90 Watts at 12 volts will require 7.5 Amps.
>>> 8 hours would use 60 Amp-hours which seems to be within a 12 volt deep
>>> cycle battery capability.
>>> 
>>> Now the real world   Guess (I have no clue) that the 24 volt supply is 85%
>>> efficient, the inverter 60% which will require 177 Watts at 12 volts or
>>> 14.7 amps, beyond the capability of a battery.  Now if the device only
>>> needs half that 3.75 Amps you have a much better situation.
>>> 
>>> Of course a boost regulator that gets rid of all that inefficiency would
>>> work a lot better but that would cost money.
>>> 
>>> Somebody check my math.
>>> 
>>>    1. NAC.  That's right, absolutely NAC.  Electrical question
>>> 
>>>       (John Larson)
>>> So I have this former customer, a charity case, pretty much, with a
>>> sleeping/breathing problem.  He lives in a 1970 VW bus with only
>>> occasional access to 110v power.  He uses a respiration helper device
>>> when he sleeps.  I have the label for the power supply (which has a 24v
>>> output at 3.75A), and I need to figure out what kind of load that'll put
>>> on a 12 battery through a 400w 90A inverter.  He already has the
>>> inverter so we want to try to use it.  I'm planning to install some kind
>>> of battery isolator, possibly a Ford starter relay (of which I have a
>>> number) activated by the KOEO position on the ignition switch.  If it
>>> would be better, I can purchase a dedicated component.  I'm planning on
>>> using a deep cycle battery and keeping it charged with the alternator
>>> (and possibly a solar panel, if necessary).  I know there are some of
>>> you that can do the math while walking and chewing gum, so this one
>>> should be a breeze!  I'm not one of those people ...................
>>> Would it be better to just use a 12vDC>24vDC device and forgo the
>>> 12vDC>110ACv>24vDC?
>>> 
>>> Cost effective way?  Best way?
>>> 
>>> Thanks!  John
>>> 
>>> 
>>> 
>>> _______________________________________________
>>> quattro mailing list
>>> quattro at audifans.com
>>> http://www.audifans.com/mailman/listinfo/quattro
>>> _______________________________________________
>>> quattro mailing list
>>> http://www.audifans.com/mailman/listinfo/quattro
>>> http://www.audifans.com/kb/List_information
>>> 
>> _______________________________________________
>> quattro mailing list
>> http://www.audifans.com/mailman/listinfo/quattro
>> http://www.audifans.com/kb/List_information
>> 
> _______________________________________________
> quattro mailing list
> http://www.audifans.com/mailman/listinfo/quattro
> http://www.audifans.com/kb/List_information