Regardless, relying on the constant-rate integral voltage regulator that came with your engine will earn you a charge of gross negligence against your new high-tech batteries. To maximize your battery return on investment, you need a programmable voltage regulator and will want to set up temperature monitoring at least at the batteries and, if you’re using a high-output unit, preferably at both the batteries and the alternator. The Pro-Digital regulator offers output settings for a range of batteries: conventional flooded-cell batteries, on which you have cell access for topping up depleted electrolyte; sealed flooded and certain A.G.M. batteries; and some gel-cell models. There’s also an additional setting for other gel or A.G.M. batteries, depending upon the battery manufacturer’s specific voltage requirements. It also has inputs for temperature sensors. The software within the regulator automatically calculates the battery-bank size, charge state, and alternator output, and it sets the microprocessor to adjust appropriate charge phase-time durations.