Between Uses: Looking After Spare and Infrequently Used Batteries

A spare battery is only useful if someone can find it, understand its condition and put it back into service appropriately. The weeks between jobs deserve a plan of their own.

Think of the inspection instrument used twice a year, the grounds team’s seasonal tools or the extra laptop kept for a new starter. None is part of a busy daily charging routine. Each can sit quietly until somebody needs it in a hurry.

Our previous article examined charging after staff leave. Here the question is different: how should a workplace look after serviceable lithium-ion batteries and battery-powered equipment while they are waiting to be used?

Start with why the battery is waiting

“Spare” can hide several different situations. Give the record a status that explains the intended next step:

• Working spare: expected to return to normal use soon, with a known equipment owner.
• Infrequent or seasonal use: a device with a longer gap between jobs and a planned return date or review point.
• Awaiting a decision: equipment whose condition, compatibility or future purpose is unresolved.

The third group should not quietly become available stock. A battery awaiting assessment, recall instructions or disposal needs its own managed process. A shelf label saying “spares” does not resolve that uncertainty.

This article concerns ordinary portable workplace equipment. Installed standby systems, emergency equipment and larger battery installations need their own operating and maintenance arrangements; do not apply a portable-tool storage routine to them.

Use the storage instructions, not a universal percentage

A battery’s charge level for a working shift and its recommended charge level for months in storage may be different. “Charge everything fully before putting it away” is not a reliable rule for a mixed inventory.

For example, Apple’s long-term storage guidance recommends around 50% charge for its devices, powering them down and restoring that level every six months if storage continues beyond six months. It explains that prolonged storage fully discharged or fully charged can harm battery performance.

STIHL’s U.S. storage guide gives different charge ranges for removable batteries and integrated-battery tools, and directs users to their battery and tool manuals. It also recommends rotating spare batteries through use.

These examples show why the record needs a reference to the actual instructions. They are not settings to copy across the workplace. Record the specified charge condition, preparation steps and follow-up interval for each equipment type. If the instructions are missing or unclear, ask the manufacturer before making a local rule.

Leaving something connected to a charger indefinitely is a charging arrangement, not simply storage. Review it under the relevant equipment instructions and the workplace’s charging procedure.

Check what happens around the storage location

A place that is convenient today may change during a shutdown or a busy delivery period. Look for sunlight through a window, nearby heat sources, moisture, materials accumulating around the equipment and the possibility of impact or crushing.

Health Canada’s safety guidance advises dry storage away from extreme temperatures and warns against placing heavy objects on boxes containing lithium-ion batteries. Follow the equipment’s permitted storage conditions, and keep required escape routes clear.

Neither a neat shelf nor a closed case demonstrates fire containment. Storage quantities, surroundings and any need for additional protection belong in the site assessment. Review the arrangement when those conditions change.

Give a rarely used item an owner and a next date

Equipment that nobody uses regularly can fall outside everyone’s routine. Assign responsibility for reviewing its record and arranging any checks or maintenance required by the manufacturer and site procedure.

A calendar reminder should name the task, not just say “check batteries.” It might ask the owner to confirm the storage conditions, review reported issues and arrange the manufacturer-specified charge check. The interval needs a basis; a convenient monthly reminder is not a technical maintenance specification.

Storage and charging temperature limits may differ. Allow for the manufacturer’s required preparation when equipment moves between environments; do not assume that a pack brought in from a cold store is immediately ready to charge. Our charging-routine checklist covers the next stage.

If a concern appears, stop normal use and follow the site’s reporting procedure. Smoke, hissing, venting or rapidly developing heat calls for the emergency response: move away, raise the alarm, evacuate as instructed and contact emergency services from a safe location. Do not carry an actively failing battery to another storage area. See warning signs and what to do next.

A spare-battery record you can use

Add these fields to your existing equipment register rather than creating a separate system for its own sake:

1. Identity and purpose: asset reference, battery model and the equipment it supports.
2. Status and location: working spare, infrequent use or awaiting a decision; where it is held.
3. Storage instructions: document reference, preparation, charge condition and permitted environment.
4. Responsibility: named owner and cover during absence.
5. Next action: required check or maintenance task, due date and the basis for that interval.
6. Return to use: checks completed, unresolved issues and the person responsible for resolving them.

Keep unknowns visible. A blank field should generate an action, not be interpreted as “no requirement.”

Start with one cupboard, equipment bay or seasonal kit. Use your battery inventory record to identify which items have a purpose, an owner and a next step. That is a useful improvement even before the whole site is reviewed.

Continue with A Battery Has Been Reported as Damaged—What Happens Next? to follow a concern through to a confirmed outcome.

Prepared by Battery Safe Systems, October 25, 2026. General educational guidance for portable workplace batteries; follow manufacturer instructions, site procedures and applicable requirements. Images and scenarios are illustrative and do not show certified storage arrangements.