I have 5 Norsk batteries (2) 36V for trolling motor, (2) for starting, (1) dedicated graph battery. This is my first year with them and the research I have done says take them to 50% before putting them to sleep. I charged them about a month ago and never made it back out. They are all mostly charged still. Wondering if there is a way to discharged them before I put them to sleep. I am in North Dakota and have pulled them out and have them on a shelf in the heated shop for the winter already.

For optimal performance and longevity, store your Norsk Lithium Marine batteries in a cool, dry location with a charge level between 50–60%.

Since your batteries have already been removed from your boat, you may either discharge them to the recommended range using an external source or store them at their current charge for this season. When preparing for storage in the future, aim to maintain the 50–60% charge level. Storing batteries at a higher charge for a single season will not cause harm; it would require multiple years of high-charge storage to negatively impact the lithium cells.

If you choose to discharge your batteries before long-term storage, the simplest approach depending on your setup is to connect them to your boat’s equipment (such as the trolling motor or electronics) to draw down the charge. If the boat is already in storage, you can use a high-voltage LED light bar (rated up to 48V) connected to the battery terminals to safely reduce capacity.

Once your battery is charged and ready for storage, we recommend placing it into Deep Sleep. This function completely disconnects power from the terminals, preventing any drain from electronics or accessories and helping preserve the battery’s charge.

Deep Sleep can be activated through the Norsk Guardian App or by pressing the Power Management Button located on top of the battery case until 3 lights are illuminated.

For additional details, visit the Norsk Lithium website.

**Storing your batteries at the 50-60% battery capacity is ideal conditions. Storing your batteries at a higher battery percentage will not harm them for one season; it would take multiple years of long-term storage at a high battery percentage to negatively affect the lithium cells.