Voltage Regulators are one of your best investments in your power system.  A good one will extend battery life, maintain a full charge, and save you a lot of money on batteries, which are more expensive than a good regulator.  They reduce running time to a minimum saving on fuel, oil, and maintenance.  Let us decrease your carging time if you don’t have a smart regulator.  Let’s look at some definitions and types. 

Smart regulators definitely relieve you of charging chores, allowing more pleasurable cruising.   Today’s smart regulators are really mini-computers containing microchips which think for you.  They sense battery voltage and change charging stages automatically.  Some “soft start” the charging regime in stages allowing the engine oil to circulate before loading the engine.  Some have manually adjustable voltages and currents, others requires the selection of the battery type and then automatically adjustment voltages.   These regulators provide proper charging and float voltage points.  Most have light emitting diodes (LEDs) and self diagnostics which alert you when a problem exists.  Here are the different stages of charging. 

Bulk Charge: The regulator drives the alternator to full output, or bulk charge, and keeps it there until the adsorption voltage of 14.1 to 14.4 volts is reached depending on battery type.  During the first hour of charging, 60 to 160 amp hours (AH) can be put into the battery system depending on the alternator.  The bulk charge will provide 85% charge. 

Adsorption Charge: After the bulk charge the regulator switches to holding the adsorption voltage constant, batteries continue to charge, taking all the amps the battery will accept at that voltage.  Charging amps will slowly drop off an amp or two a minute until it reaches 5 to 15% of the bulk charge rate.  Once the adsorption charge is complete, the battery should be floated at a lower voltage eliminating overcharging.  This transition is what the non-adjustable and internal voltage regulators cannot do.  The adsorption cycle will add another 13% charge leaving your batteries about 98% charged. 

Float Charge: A float voltage of 13.2 to 13.8 volts, slightly lower than the adsorption voltage, should remain on the batteries while charging as long as the batteries are near full charge.  A float voltage will allow charging current to increase to meet various loads, but still not overcharge the battery. 

Equalizing Charge: To lengthen battery life, periodic equalizing charges are desirable on liquid lead batteries only.  DO NOT equalize gel cell batteries and Lifeline batteries do not need equalization.  After batteries are full, a charging current of 3 to 7% of amp hour capacity is applied letting voltage rise to 15 to 16 volts but keeping the current constant for 3 to 5 hours.  This equalizes cells and eliminates any small amount of sulfation, which may have occurred.  CAUTION: all electronics, even lights, must be off during equalization.

Sensing Voltage & Temperature: Voltage regulators must sense battery voltage.  Some sense at the alternator output while others at the battery post.  Battery post sensing is more accurate; and isolators can be used without changing regulator calibration.  Sensing voltage is usually done on the house battery.  The SAR includes temperature sensing to prevent damage when battery heat rises too high, or it increases charging voltage in cold climates. 

Timers: Some voltage regulators incorporate internal timers to prevent overcharging batteries already charged, as well as, those with bad cells. 

Regulators not recommended: Internal or non-adjustable voltage regulators are inadequate for deep cycle batteries and the high AmpHour consumption of modern boats using DC refrigeration.  If you already have one, we will show you how to wire it as a spare for emergency use.  If a smart regulator fails, flip of a switch will resume charging.