Smith-Root LR-20B Backpack Electrofisher

The lightest weight and lowest cost backpack electrofisher (while still providing ruggedness and industry leading capabilities!).

A benefit of the LR-20B is the simplified manual control knobs and streamlined settings that allow for rapid adjustment of output frequency, voltage, and duty cycle. These rapid controls are housed inside of a non-conductive, waterproof enclosure with a shatter resistant cover. The externally accessible anode and cathode plugs and battery connector make the connection of electrodes and battery packs quick and easy.

At 400 Watts of Power, the LR-20B backpack is the most affordable Per Watt electrofisher on the market.

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All Smith-Root Backpack Electrofishers come with a free voucher to enroll in our industry leading course: Electrofishing Principles and Safety Certification Course.

The LR-20B has the following features:

  • 400W continuous output power
  • Easy to use rotary style controls
  • Rugged and safe design
  • Standard 1 year warranty
  • Made in the USA

LCD Display

The easy-to-read backlit LCD display shows real-time status of output voltage and current, fuel gauge-type display of the battery life, output time in seconds, unit temperature and waveform settings.

Output Controls

The rotary Output Frequency switch controls the frequency (pulses per second) of the LR-20B in 5 and 10 hertz increments. The Duty Cycle switch controls the percentage of time the output pulse is on. It also allows switching to straight DC or gated bursts of either 2 or 3 pulses. The timer reset button resets the number of seconds the output of the LR-20B has been active.


Operator safety is a primary concern in the design of Smith-Root electrofishers. Tilt sensor, water immersion sensor, and cover open sensor will automatically shutdown the electrofisher. A power output audio alarm and flashing light let all members of the collection crew know the electrofisher is active.

Packframe and Suspension

Adjustable suspension harness and packframe can be customized to fit most people. Quick release latches allow the LR-20B to be removed quickly if the operator falls or becomes injured.


The LR-20B uses the same electrode, cathode, and battery connectors as the LR-24 and Apex backpack electrofishers. This will increase your flexibility in large field operations and increases the versatility of your inventory of electrofishers.

LR-20B Electrofisher Specifications

Output Power 400W continuous, 39,600W peak
Output Voltage 50 to 990V in 11 steps (50 to 400V in 50V steps, 500V, 700V, 990V)
Output Frequency 10 to 120Hz in 16 steps (10 to 50Hz in 5Hz steps, 50 to 120Hz in 10Hz steps)
Duty Cycle 5 to 50% in 5% steps, 60 to 80% in 10% steps, Gated Burst 2 pulse, Gated Burst 3 pulse, DC
Overload Protection Automatic electronic and 40A safety fuse, High output current, Output voltage out of regulation, Over temperature
Safety Features Emergency shut off switch, Output active super-high brightness red LED, Output active audio alarm, Output off immersion sensor, Output off tilt sensor, High output current protection, Pole mounted output control switch, Electrode out-of-water shut down sensor, Non-conductive lightweight pack frame, Quick release harness
Timer 6 digit computer controlled seconds counter
Metering Mean current, Peak output voltage, Average output power, Battery voltage, Battery current, Battery fuel gauge, Timer
Battery Choice of 24V lithium or lead-acid batteries
Size Height: 29.75 in.
Width: 13.75 in.
Depth: 13 in.


Contact Information

Tammy Lucas
Phone: (360) 573-0202


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