Interference is a common sonar issue. Excitement turns to confusion when the owner of a brand new sonar suffers from electrical interference. Its extremely frustrating when fit up is on point and it appears your hard earned has been wasted.
There can be many reasons for electrical interference. Many I can touch on later, but there is one which seems to be a common trend since the introduction and surging popularity of electric trolling motors and the use of inline DC to DC chargers.
Inline DC to DC chargers are a great invention. They’re simple to fit and quite inexpensive given their purpose. They allow on the water charging of trolling motor batteries using the output of the outboard.
Firstly, This is not to designed to brand bash Sterling Power Chargers, they are fantastic, durable and IP68 rated chargers. However, during the last few years I have seen a common trend form with them.
The issue is when the trolling motor when in use, causes severe electrical interference on the sonar. But why?
Although chargers should have a non return voltage regulator built in, to prevent discharge of power from the charged battery. It seems that for the Sterling Power charger continues to produce this fault. The electrical interference appears when the trolling motor is in use or under load. I believe it is due to the link between trolling motor batteries and house/accessories battery. While the trolling motor draws current, power leaks back to the house/accessories battery causing electrical interference on the sonar.
So is there an easy fix? Yes, install a switch or idolater in line to isolate the connection from house/accessory battery to trolling motor battery. All this means is that while the trolling motor is in use the charger is switched off and only switched on while travelling from A to B with your outboard. This will ensure you are taking advantage of that precious outboard power output.
So if you are looking to install a Sterling DC to DC charger, take the time to put in a switch. It will save you the heartache and frustration later!
TIME & TIDE WAIT FOR NO MAN…