dan;
How are your wiring skills? A couple ideas come to mind. How about a
relay to disconnect the charger from the battery? Two things to keep in
mind, the contacts must be rated greater than the charger output. I
would go with twice the current rating. Second the  coil voltage . I
would use 110Vac and hook it up in parallel with the input to the
chargers transformer. That way when there is power to the charger the
coil will be energized and its contacts closed connecting the charger to
the battery. when the charger is off the contacts would be open and NO
battery drainage would result.If something went wrong with the circuit
hopefully the chargers fuse would blow also disconnecting the relay.
Good Luck
Ken Lewis
kdlewis@juno.com
86 VW crewcab
85 VW Vanagon GL
60 356 coupe

On Mon, 4 Nov 1996 13:05:54 -0600 Rocko Flamefart <-@--.--> writes:
>Ron had asked if anyone has added a charger to their battery system.
>
>aa-yup.  sorta.  for a while.
>
>but my primary purpose was to assist winter starting.  in the 
>passenger side
>battery box i had added a battery blanket (works wonderfully) warmer 
>and
>also wanted to add a charger to keep the battery topped up.
>
>i just connected the leads of the charger right to the cable clamp 
>bolts,
>ran the leads outside the battery box thru an indentation in the box 
>i'd
>made for the battery blanket cord.  plugged the charger into a flat, 
>HD
>extension cord i have running from the 110v outlet inside the cabinet 
>under
>the sink over to the battery box.  was pleased as punch.  i plug in 
>the van,
>the battery warms and charges.
>
>then i thought "i wonder how much leakage the charger diodes have" as 
>they
>are made to be connected only when it is plugged in to 110v.  
>measuring the
>reverse current going back into the charger, the diodes allowed about 
>3 mA
>leakage.  not much but it bothered me.  so i unhooked the charger :(  
>
>i may reinstall it with a better blocking diode in place and would be
>grateful for any PN suggestions.  should be able to handle about 10 
>amps.  i
>realize the clock, radio, and ECU parasitic draw probably exceeds 3 mA 
>but
>since this is so easy to hook/unhook i thought i'd experiment a little 
>with
>getting the leakage to near zero.  
>
>-dan
>