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[dbdb]

I now have a battery minder installed.  On test it cuts the battery off when the voltage under load drops to 10.9V for a period of time.  That is Ok, believe it or not it easily leaves the battery with enough power to start the car (returning to 12.3V if left to rest).  I wouldn't mind if the cut off was higher but my main aim is to reduce the draw of the device which is 17ma.  Not a lot but seems to defeat the purpose if the device itself is draining the battery. The device is potted so I can't get at it but I assume the 17ma standby draw is a small solenoid. Obviously I can't get the draw to zero but a bit lower would be good. 

So what I'm planning to do is put a small resistor inline between the device (which is bolted onto the 12V+) and its wire to the negative terminal to reduce the draw and probably up the cut out voltage.  I'll just play around with a few different resistors but can anyone suggest a starting Ohm figure? I assume 1/4W rated resistor will be OK but may use two 1/4Ws in parallel.

[zirk]

Assuming the Voltage sense is different to the 12v feed for the minder you could try your resistor idea, problem is if the sense feed is the same as the supply Im guessing your then have a resistor in line with the cut out relay so your end up with different Voltage potential difference across the resistor as it draws different currents.

One thing you could try is to put high amp'ish Diode in line with it, that should in theory drop the feed  voltage by 0.7 volts, ie Battery Voltage drops to 11.6 V, sensor thinks its 10.9 V after the diode etc.