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[Clansgian AT wmconnect.com]

> >I had no idea of how large a 50 watt panel was so I searched around and
> 
50 watts for a fence charger???  Way overkill!  And I don't care how heafty 
the charger is.  A fence charger (in terms of power, and watts are a measure 
of 
electrical power) uses very very very very little electrical power.  Under 
perfect conditions it would use none at all.  At each cycle it would present 
the 
kilo-volatge along the wire with no current at all.  Any volatage x no 
current = no power.  (This of course does not count when an animal touches 
the 
fence, then a LITTLE power is used).

But there are no perfect conditions.  The very high voltage discharges very 
slightly and the longer the fence the more the discharge.  More importantly 
the 
fence wire has a characteristic impedence and this makes the charge a bit out 
of phase along the fence and uses up some power in the process.  And the 
internal circuit and mechanism of the charger uses a trace amount of power.

Many wimpy battery powered and solar powered fences have very wimpy 
batteries.  It isn't the power capacity of the batteries that's the problem 
but how 
quickly the batteries can  deliver the current to charge the charger's 
capacitive 
circuit for the next cycle.   Weak or wimpy batteries or systems designed 
around batteries with too low a voltage can only charge up the capacitive 
circuit 
of the charger part of the way for each cycle and so the shock is weak.

Solar fence charges need an adequate battery.  With that, a 50 watt pannel is 
super way overkill.  The battery could be fully maintained  for 24 hours if 
it could be charged for 10 hours at half a watt.

Also keep in mind that they design some of these elephant scorcher charges to 
charge 100 miles of wire.  If you want a reasonable shock at the end of that 
100 mile circuit, you need some current (and hence some power [wattage]) to 
maintain that.  But if you are fencing in a dozen acres or so, the power 
requirements for a good shock are many magnitudes less.

James