battery switch

[Rod Johnson]

With reference to auxiliary battery charging discussion, as mentioned in the meeting last night:

 

 Brad showed a nice example of a sophisticated battery switch, which allows running radios off either the engine or an auxiliary battery.

  For a less exotic setup., I have used these $25 voltage controlled switches ( or similar)  with good results.  They sense the vehicle charging system voltage, and automatically cut-in at a little over 13 volts to charge the aux battery.  If the charging system voltage drops below about 12.8 (IIRC) the relay drops put, disconnecting the vehicle system from the aux system.   The relay is rated at 140 amps, so that should provide plenty of reserve capacity for the relay contacts under normal use.

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