[RE-wrenches] Charging with "no contact" systems

[robert ellison]

Walt,
Probably about the best bet is another set of inverters just as chargers.
Look at the Magnu 4448AE inverters, they have a great charger that draws
less incoming ac that any of the other chargers that I have tried. Seems
that 2 of the 4448 inverters will each put about 60 amps DC into a battery
bank with only 17 amps in @ 240 volts or 34 amps ac @ 120 volts.

Just another wrenches opinion,
Bob
On Tue, Sep 30, 2008 at 10:57 AM, Walt Ratterman <
wratterman at sunenergypower.com> wrote:

>  Hello all,
>
>
>
> We have an application in Haiti (and some African countries as well) where
> we have inverter /battery systems on a lousy (very lousy) grids.  The grid
> is good enough to charge batteries, but not sufficient for sensitive
> electronic loads.
>
>
>
> Therefore, the systems we are using are three Outback FX 3648 inverters.
> If they are connected with AC IN from the grid and the grid is on and is
> lousy (but good enough to get through the voltage and frequency limits),
> then this power will be passed on to the computers.  (The reality is that we
> have to open the voltage window too wide to let the grid in at all, and thus
> unacceptable to the electronics.)  So, we DO NOT connect the AC IN to the
> inverters.  In other words, the FX units become inverters only, and never
> pass AC current from the grid to the loads.  (This is what we are calling
> "no contact" system – similar to a double conversion UPS system.)
>
>
>
> So – we need to add separate battery charging to the battery bank that will
> put in roughly equal amphours to what we feel the daily usage will be during
> the day.
>
>
>
> The load is about 8000 watts, which might translate to 140 to 170 amps of
> discharging.  We might not have to put in the full amount of charge, since
> our charging can continue in the night hours when the load is not
> discharging, but we should probably try to charge the batteries at around
> 100 to 140 Amps DC (48V).
>
>
>
> Does anyone have a recommendation as to the type of charger that might work
> best for this, either bulk, or smart, or a combination?  OR……other
> suggestions for this system that I am just missing??
>
>
>
> We would plan to monitor this system by using the FlexNET DC system, adding
> a DC shunt on the negatives of the feed going from the charger TO the
> batteries.
>
>
>
> Thanks,
>
>
>
> Walt
>
>
>
> *Walt Ratterman*
>
> *SunEnergy Power International***
>
> * *
>
> 11 Laurel Lane South     Washougal, WA   98671
>
> (360)-837-3680   ▪   fax (360)-837-1315   ▪   Skype  Walt-Mobile
>
> wratterman at SunEPI.org   ▪   www.SunEPI.org <http://www.sunepi.org/>
>
>
>
>
>
>
>
>
>
>
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