Off-Season Storage: Fish Finder, Battery and Transducer Checklist

To store a fish finder for the off-season, clean and dry the display, transducer and cables, take the battery off the boat, look after it according to its chemistry, and keep everything in a cool, dry spot out of direct sun. Then write down what needs attention in spring while you still remember it.

This is a layup checklist for anglers who put the boat or kayak away for months. It is general care; your unit's manual and your battery maker's instructions are the final word on storage temperature, charge level and cleaning products.

01Clean and dry before you store

Put things away clean and dry, because dirt and moisture are what cause trouble over a long layup. Start with the head unit, then the transducer and cables.

• Display and case. Wipe the screen and housing with a soft microfiber cloth. Use only cleaners your manual allows on the screen coating. Our cleaning supplies guide covers what to look for.
• Transducer face. Remove film or growth gently, with a soft cloth and plain water, unless the maker says otherwise. Do not scrape the face with a hard tool.
• Cables and connectors. Wipe them dry and let them air out before you cap or coil them. Moisture sealed into a connector can cause corrosion over months.

If the unit was used in salt water, rinse it with fresh water as the manual directs, then dry thoroughly. Our maintenance guide has more on year-round care.

02The storage checklist, step by step

1. Save your data. Copy waypoints, tracks and sonar logs to a card or your phone before you power down. Our guide to sharing waypoints between devices explains the options.
2. Power down and disconnect. Turn the unit off and unplug the power lead. Leaving a unit connected to a battery for months can drain the battery and is not what the manual intends.
3. Remove the display if it is removable. A bracket-mounted or quick-release unit is safest indoors, away from freezing air, heat and thieves.
4. Inspect the transducer and cable. Look for cracks, nicks, frayed jacket or a loose plug. Note repairs now rather than in spring.
5. Cap or cover open connectors with the plugs or caps that came with the gear, so dust and moisture stay out.
6. Coil cables loosely. Avoid tight kinks and sharp bends, especially near connectors.
7. Store in a cool, dry place away from direct sun and heat sources. Check your manual for the unit's storage temperature range; we quote none because it varies by model.
8. Write your spring to-do list and tape it to the case.

If your unit stays on the boat, cover the screen, disconnect the power and keep the boat dry. A fitted cover helps with sun, and our visor and cover guide explains fit.

03Battery storage by chemistry

The battery is the part most likely to be ruined by a winter in the garage. Battery University's storage guidance gives the general picture: most batteries are best stored in a cool place, heat speeds permanent capacity loss, and discharged batteries are more prone to freezing damage.

Lead-acid and sealed lead-acid

These batteries self-discharge during storage, so they need periodic checks. Battery University says to recharge before the charge falls too low, because a low charge leads to sulfation, a layer on the plates that reduces current flow. In practice, that means storing the battery fully charged, checking it from time to time and topping it up as the maker directs.

Lithium-ion

Battery University recommends storing lithium-ion cells at a partial charge rather than full, because a full charge causes larger capacity losses, and avoiding deep discharge, which can make cells unsafe to recharge. That is general guidance for lithium-ion chemistry.

Marine lithium packs

Trolling motor and marine lithium batteries, including lithium iron phosphate packs, have their own electronics and storage instructions. Follow your battery maker's guidance on storage charge, temperature and whether to connect a maintainer. When the maker's instructions and general guidance differ, the maker wins.

For help choosing a battery or charger, see our battery guide, and for what the cold does to batteries during the season, our cold weather care guide.

04Pick the right place and protect the gear

A good storage spot is cool, dry and out of the sun. Attics and unheated sheds can swing between extremes, and a spot that sweats in humid weather risks moisture on connectors. An indoor closet or shelf is usually safer than a garage corner, though your manual's storage range should decide.

• Use a case. A padded case keeps dust off and prevents bumps. If the case is sealed, make sure the gear is dry first. Look for a case with room for cables and a small accessory pouch.
• Keep pests away. Store cables where animals cannot chew them.
• Avoid stacking weight on screens, transducers or cables.
• Label the box with the unit, the battery and the date you stored it.

05Leave a note for spring

The best off-season habit is the one that makes spring easier. Before you close the box, note any repairs, missing parts, software updates to install and batteries to charge. Our guide to updating software and maps is a good reference for that list.

Take a quick photo of the wiring and connections before you disconnect anything on the boat. It saves guessing in spring.