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Regulator Comparison ...SAR V3 and Next Step, NS2


The NS2 is the latest Ample Power Regulator. It was designed as an entry level regulator but with a series of options. With all the options, the NS2 has the functionality of the SAR V3, however the optional serial port is required for many of those functions. A computer with a serial port is also necessary.

For those with a computer, the NS2 with options is easier to use. For instance, current limit in the V3 is set by a potentiometer and requires an ammeter to measure alternator or battery current. With the NS2, current is programmed as a percentage of alternator maximum.

The table below lists functions and their implementation on the two regulators.


AGM and liquid electrolyte batteries require periodic equalization. A cruising vessel which can't rely on shore power for this purpose should select the V3, or go with all the NS2 options.

The V3 can equalize via an internal jumper selection and an external input to start the equalization cycle. The NS2 requires a computer to start the cycle. Those comfortable with a computer will be best served with the NS2.

Regulating Two Alternators

The V3 can drive the field of two alternators directly. If the two alternators are on separate engines then a Dual Alternator Controller, DAC is required. The V3 and DAC combination work well in power boats where the two engines are side by side. In multi-hull vessels, where the engines are a great wiring distance from each other and the house battery bank, problems with RFI noise and regulator stresses from transients on the field wire make the V3/DAC method less than optimum.

The NS2 addresses this problem by utilizing an Alternator Driver Module. The NS2 itself is located near one engine, and the Driver near the other engine. High power field connections are short and thus RFI and transient problems are much less. Wiring is also simpler.

Regulator Setpoints

The V3 has a dipswitch to select the type of battery in the system. It bases absorption time on the battery selection and other dynamic measurements. In most cases the V3 does an excellent job of delivering a fast full charge.

The NS2 provides potentiometers for absorption and float voltages, and absorption time. They can also be set via the computer and saved in non-volatile memory. The NS2 should be selected if you want to use non-standard setpoints.

Regulator Size

The NS2 is about 1/4 the size of the V3.


The NS2 can communicate using a subset of the Remote Access Protocol, RAP. With the optional serial port, the NS2 will be compatible with future displays offered by Ample Power and others.

Feature SAR V3 Next Step NS2
Battery Combiner Mode Standard Optional
Temperature Sensor Standard Optional
Equalization Standard Optional Serial Port
Absorption Lock Standard Optional Serial Port
Adjustable Setpoints Dipswitch, 8 types Yes
Two Alternator Drive Standard Optional
12/24 Volts One or Other Works on Either
32/36/48 Volts No Yes
Computer Interface No Optional Serial Port
Firmware Upgrade Replace Chip Re-program Flash
Pluggable Terminal Blocks Yes Yes
Short Circuit Protection Electronic + Fuse Fuse
Read Battery Voltage No Optional Serial Port
Read Battery Temperature No Optional Serial Port
Duty Cycle Current Limiting Standard Optional Serial Port
English Status Messages No Optional Serial Port
Remote Status LED Standard No
English Error Messages No Optional Serial Port
Remote Error LED Standard Optionl

Ample Power products are manufactured by Ample Technology, 2442 NW Market St., #43, Seattle, WA 98107 - USA