Posted by Neon John on August 2, 2008, 6:28 am
Does anyone know of a source of inexpensive 24 or 48 volt input modified sine
wave inverters? I'm not interested in the high dollar Outbacks and Xantrexes
and stuff. I'm looking for a higher input voltage version of the $49 2500
watt inverter that Harbor Freight sells. Neither output waveform quality nor
a built-in charger is important in this application. Just a simple 48 volt
in, 120 volt out inverter will do. Mild googling hasn't found me anything.
John De Armond
See my website for my current email address
http://www.johndearmond.com <-- best little blog on the net!
Tellico Plains, Occupied TN
Hell is truth seen too late. -Hobbs
Posted by Ken Maltby on August 2, 2008, 8:23 pm
I don't know how much help this will be, but I picked up a
Datashield AT-1500 for $.95 when a local electronics
supply outfit was cleaning out one of their warehouses.
It is an UPS that runs from an external 48v battery bank.
The one I've got was never used (or sold, I expect) but it
is as solid as a rock and I can't see much that would make
a used one go bad. You might get lucky, with an old 48v
UPS at a low price. Just another option you might not have
Posted by Vaughn Simon on August 2, 2008, 9:37 pm
For a variety of reasons, UPSs generally (there may be important exceptions)
don't make good substitutes for inverters.
Posted by Ken Maltby on August 2, 2008, 10:46 pm
I'll take your word for it, that there could be issues for such
broad classifications as "UPSs" (which would cover a range
of devices) and what being "good substitutes for inverters"
might involve. (The one I mentioned weighs over 35#, so
it might not be the best choice to power a laptop in your truck.)
[ but with 1500watts to work with ...]
In general, I don't see a lot of difference between an inverter
and an UPS that is unplugged/disconnected from mains power.
The one I mentioned and a number of the older office appliance
commercial grade UPS were designed to use external battery
banks. Admittedly the charging circuits would go un-used, but I
don't see how that would prevent them from functioning as
Then there is what "Neon John" actually asked for in his post:
"Neither output waveform quality nor a built-in charger is
important in this application. Just a simple 48 volt in, 120 volt
out inverter will do." The old UPSs can certainly meet that
list of requirements.
Now the UPS will have "a built-in charger", but you don't
have to plug it in. (You might have to disable the alarm circuit,
though. [ I'd wire in a disable/shutoff switch for the alarm, in
case I wanted it when/if I occasionally charged the battery bank
from the mains or a generator.]
Now, I am very curious as to what those "variety of reasons"
might be. If nothing else, they can be things to look out for when
I finally put the one I have to use.
Posted by Bob F on August 3, 2008, 12:07 am
The (smaller) UPSs that I've played with don't turn on the output unless A/C
power is on. Then, when it goes off, they continue to output.