The 4 Position (Dual) Battery Switch - How to Choose Wisely
Apr 18, 2016 03:44 pm
Skier’s Choice installs a 4-position battery switch on any boat equipped with dual batteries. Choosing the proper position can either be the start of a great day on the water, or the start of a bad day. Here are a few tips to help you have a good day.
A good day on the water starts with the last time you used your boat. We always recommend that both batteries be fully charged between each use to insure they can deliver the electrical demands required for each outing. That is why we install chargers on all dual battery models. Keeping both batteries charged will not only make them last longer, it will help ensure uniform performance for your electrical system each time you are on the water. Simply plug the charger into an outlet when you return home, to keep the batteries fully charged for your next trip. It does not matter which position the selector is in while charging. Both batteries will charge until fully charged, then the charger will monitor them so that they stay topped off.
Proper Battery Installation - The proper battery cable configuration is important. All of the boat’s Negative Grounding leads (engine, dash, stereo) need to be on the same battery. This insures that everything is at the same ground potential also referred to as the ground plane. The terminals need to be installed so the biggest is on the bottom and the smallest terminal is on the top. The second battery should only have the battery charger leads and the Black 2/0 Ground strap that connects it to the first battery and the 2/0 Red positive battery lead that goes to the battery switch.
If the ground leads are not all put on the same battery, the ground plane difference between the batteries can wreak havoc on electronics in the boat (The difference in Ground plane is due to non- matching batteries, corrosion, loose connection, etc.). When the boat’s circuits have multiple ground planes, the electrical flow in the circuit can be erratic and the result can be electronics do not process signals correctly. This can range from dash screens freezing up, to GPS signals being dropped and even to stereo systems acting crazy. The result may be temporary, or it may damage or fail a component.
The 4 positions available on the battery switch are: Off / 1 / 2 / 1&2 These choices indicate which battery is being used to power the boat and which battery is being charged by the engine’s alternator. We recommend using only position 1 or 2 while boating. The purpose of our recommendation is to utilize one primary battery for all operational needs, and have the other as a backup if the primary battery discharges. This situation could occur if you run your accessories such as ballast or stereo for a long time, without running the boat.
Battery switch position 1&2 is available but not recommended as power will be drawn from both batteries and the alternator will have difficulties keeping both batteries charged simultaneously. It can ruin your day on the water and potentially leave you in dangerous situations. The only time you may need Position 1 & 2 would be in an emergency situation where you might be low on both batteries and need both to help start the boat.
NEVER CHANGE BATTERY SWITCH POSITIONS WHILE THE ENGINE IS RUNNING – THIS WILL DAMAGE THE ALTERNATOR AND IS NOT COVERED UNDER WARRANTY. Also, in order to avoid damage to electronics, it is best to turn your key off completely when changing battery switch positions
In summary, to ensure trouble free time on the water, make sure you charge up between trips, know what battery position to choose, and power down before changing battery positions.