Re: (ET) Solar charging, part 2 :using a stationary pack

["Christopher Zach" <czach computer org>]

Yes, that is another possibility. I use a 100 watt grid-tie inverter hooked
to my main battery pile (300amps at 24 volts) to divert surplus sun power
from my panels into the grid. I do like inertae: it is the best way to get
efficiency out of a solar panel setup.

However I will say that the efficiency of my solar charger is pretty close
to 100%. The efficiency of the Elec-Trak's on-board charger is nowhere near
as good (lot o' heat). Thus by using the grid-tie approach, it is not as
efficient as charging directly from the panels.

The typical "solar" way is as follows:

Tractor gets top priority for charging
Bringing the shed batteries to 25 volts gets second priority
Rest is sold to the grid.

The batteries in the shed typically get a full charge during the morning
(the panels can put in up to 15 amps, the inverter takes out 4 tops) and
then get discharged down to 70% or so during the afternoon. The size of the
battery core is large enough that I can run tools, toys, lights in the
evening without dropping the pack below 40%.

Works pretty well actually.
Chris

----- Original Message -----
From: "Jim Coate" <jbc coate org>
To: "elec-trak" <elec-trak cosmos phy tufts edu>
Sent: Wednesday, April 23, 2003 9:13 AM
Subject: Re: (ET) Solar charging, part 2 :using a stationary pack


>
> Another variation is to use a grid-intertied system. For those of us
> already on the grid, this can be done with out any stationary battery
> pack (although won't have the blackout backup). Any solar power
> available goes into "the grid" when the sun shines and the ET is plugged
> in and charges from the grid (regardless of the amount of sun shine at
> that moment). I have just two smallish panels and an intertie controller
> (Chris Zach may have had one first that I read about??) for a 100 watt
> system. Similar to what Jeremy and Eric and all have been saying, this
> gets the most power possible from the panels as there is always some
> place for it to go.
>
>
> Eric wrote:
> >    In my opinion I think charging a stationary pack instead of directly
> > charging the Elec-trak gives you the freedom to do more (than just
charging
> > the ET). Coupling together the ability to recharge the ET along with
other
> > uses makes the investment in solar panels a wise investment. Don't
forget to
> > explain to the wife how if the electricity goes off again at least we
have a
> > back up system to hold us over till the electricity in our area is
restored.
> --
>
> _________
> Jim Coate
> 1992 Chevy S10
> 1970's Elec-Trak
> http://www.eeevee.com
>
>
>