Something Draining Cranking Battery

I work offshore & when I come home after 3 weeks, my cranking battery is completely dead. This is a new boat & motor ( 250 Pro XS S/N - 18791261 ), so this may be normal for the new outboards, but here is what I have found so far. I hooked my meter in series with the positive leads from the battery & found that the only thing drawing current is the #6 awg wire going to the outboard. It is pulling 160 ma with nothing turned on. I pulled the cowl & removed the blue wire feeding the Smartcraft Monitor & the current dropped to 80 ma. I then unhooked the cannon plug on the main wiring harness & the current dropped to zero. I hooked both these harnesses back up & went to the Smartcraft Monitor & unhooked the connector from it to see if the current was coming from the wiring or the Smartcraft Monitor. The current dropped from 160 ma to 80 ma again, which told me the Monitor itself is pulling 80 ma. The main wiring harness is going to be a little harder to chase down so I wanted to ask the experts these 2 questions before I get too involved with it.
1) Should the Smartcraft Monitor & the main wiring harness be pulling any current while it is turned off?
2) If this is normal, will it hurt to install a switch on the main wire feeding the motor, so I can disconnect it while I'm offshore.

Thanks in advance

Normal with new motors, its the buss system for data that's always pulling power.

Yes, you can install a main cranking batt. shut off switch.

JAZII

You can indeed install a battery cutoff switch (choose wisely.... current carrying capacity is just as critical as battery choice).

160 mah draw is actually pretty low for this system. I think if you dig deeper, you're going to find that something else is drawing your battery down at a higher rate... perhaps intermittently. http://www.bassboatcentral.com/smileys/wink.gif

Thanks for the info. I will keep looking for other things. I turn off the main switch feeding the keypad when I leave, but the auto bilge pump could be the culprit also. If I can't find anything, I will unhook just the motor feed & see what happens. The battery that came with the boat is not on your recommended list, so that could be a contributing factor also. I was thinking a 50 amp switch, since the wire size is 6 awg. Is that sufficient?

<table width="90%" cellspacing=0 cellpadding=0 align=center><tr><td>Quote, originally posted by my492vs &raquo;</td></tr><tr><td class="quote">I was thinking a 50 amp switch, since the wire size is 6 awg. Is that sufficient?</td></tr></table>

I would recommend a MUCH higher amperage switch. This is a DC circuit (not AC). http://www.bassboatcentral.com/smileys/wink.gif

Something more along the lines of 375-450 amp current capacity would be in order. http://www.bassboatcentral.com/smileys/wink.gif