Programmable Voltage Monitor

After installing the series regulator, I decided the SV650S needed something to monitor the charging system. A bit of google searching turned up the Programmable LED Voltage Monitor from Gammatronix in the UK. If you need to monitor something other than a 12V system, it can also handle 6V and 24V systems. More importantly, for each of these nominal voltages, you can choose from 6 different voltage maps and they're quite relevant for motorcycles. Autospeed has a helpful review covering operation and programming.

For example, mode 3 lights up solid green when charging and green/red flashing when overcharging (>15V). When charging stops and the voltage drops a bit, the operation changes to a low power mode with a brief blink every couple of seconds to indicate battery condition, green blink = happy descending thru yellow blink to red blink to completely unlit as the battery voltage decreases past 11.8V. This blinking takes about 1/2 ma and is suitable to leave connected to the battery voltage indefinitely.

The one I like is stealth mode 4. When things are healthy, the LED is off completely, nothing lit up on the dash. Overcharging is indicated by red/green flash, while lower voltages (<12.4V) cause yellow, slow yellow, red, slow red and fast red as the voltage decreases towards 10.5V. This integrates nicely with the SV650S which has no indicators on (except maybe high-beam) during normal running.


The voltage monitor requires a 14mm hole (1/2" drill and a bit of filing) and I located it towards the right of the dash under the other indicator lights. To change modes, I snake my thumb under the dash and push on the little programming button.


For a voltage source, I spliced wires with female bullet connectors into the leads for the front running light. The voltage monitor wires travel under the instruments to connect to this switched voltage source with male bullet connectors. On the SV650S, this light and the voltage across it are live in RUN and PARK positions.


With only a gentle hint, my darling daughter got me this for Christmas from the Gammatronix  eBay store. They sell other voltage monitor variants but this is the only one with stealth mode.


The voltage monitor has been exercised in the basement with the Suzuki battery and a charger to check out the modes, then installed and wired into the SV650S in the cold garage (January 2015, Ottawa). I briefly installed the battery to check out the bike wiring. Test rides will come in the Spring after the snow and salt leave the streets.

This little gizmo is working out fine (May 2015). It's set on stealth mode 4, so the light is not lit when the charging voltage is greater than 12.5 volts and less than 15 V. When you first turn on the ignition, it lights up yellow or red to show that the charging cirtuit is not charging, and more importantly, to let you know that the voltage monitor is really working.

Once the engine is running, the light is off most of the time. If I'm stopped and the engine is idling, it stays off unless the brake or turn signal is activated, dragging the voltage down.

Couldn't ask for more.