Resource Centre / Safe operation
Resource Guide 03

Battery Charging Best Practices

Practical guidance for planning and managing commercial lithium-ion battery charging — from charger compatibility and battery condition to supervision, site conditions and abnormal events.

Charging is an operating process

A safe charging strategy is more than providing electrical outlets.

Battery charging combines electrical equipment, stored energy, heat generation, battery condition and human behaviour. The resulting risk depends on how these elements interact at the actual site.

Good practice therefore starts with defining the charging process: which batteries are charged, which chargers are used, where charging occurs, how long it continues and what happens when something appears abnormal.

Battery Safe Systems — practical principle Charging capability is not the same as charging safety.

A system may provide electrical outlets without establishing charger compatibility, battery condition, supervision, heat management, detection, containment or incident response capability.

Scope of this guide

This resource provides general operational guidance. Follow battery and charger manufacturer instructions and consider applicable site rules, electrical requirements, fire-safety requirements, insurer expectations and authority requirements for the specific application.

01
Charging location

Decide where charging should occur before deciding what equipment to buy.

Charging location affects who could be exposed to an incident, what materials surround the batteries, how quickly abnormal conditions could be recognised and how emergency responders could access the area.

Charging that has grown organically around available wall outlets may deserve particular review because the location may never have been intentionally selected for battery charging.

People Who occupies the surrounding area?

Staff, students, residents, customers, visitors or members of the public can change the consequence of an incident.

Combustibles What is stored beside the charging area?

Packaging, timber, paper, chemicals, fuels and general stock should form part of the location review.

Escape routes Could charging interfere with movement through the building?

Corridors, stairs, exits and other important access routes deserve particular consideration.

Environment Are temperature and environmental conditions appropriate?

Excessive heat, sunlight, moisture, dust or mechanical exposure can affect the suitability of a charging location.

Access Can batteries be moved in and out safely?

Large or heavy batteries may require carts, lifting equipment or wider access routes.

Emergency access Can an abnormal area be approached and isolated appropriately?

Consider alarm access, evacuation, emergency responder approach and whether adjacent operations could be affected.

Practical interpretation Convenience should not be the only reason a charging area exists where it does.

Available sockets may determine where informal charging begins, but a deliberate charging strategy should also consider occupancy, adjacent materials, supervision and building protection.

02
Chargers & electrical

Understand the complete charging load — not just the number of batteries.

The charger forms part of the battery system. Use charging equipment appropriate for the battery and follow the manufacturer's charging instructions and limitations.

At fleet scale, the site should also understand how many chargers may operate at one time and whether the electrical infrastructure has been designed for the resulting load.

Battery fleet 40 batteries

Total inventory

Charging quantity 10 batteries

Simultaneous charging

Electrical demand Charger input load

Actual electrical requirement

Check Is each charger suitable for the battery it is connected to?
Check How many chargers could operate simultaneously?
Check What is the maximum charger input load?
Check Are temporary power strips or extension leads being used?
Check Is the electrical supply appropriate for the intended charging arrangement?
Check Can chargers and cables be inspected and replaced when damaged?
Important distinction Total battery energy and electrical charging demand describe different things.

Battery watt-hours help describe stored energy. Charger input ratings and simultaneous use determine the electrical demand placed on the site's charging infrastructure.

03
Battery condition

Inspect before charging — and remove abnormal batteries from the normal process.

Charging should not become an automatic step for every battery that returns to the charging area. Staff should have a practical way of identifying obvious damage or abnormal condition before the battery enters the normal charging process.

Step 01 Battery returns

Battery enters the charging area following use.

Step 02 Visual / operational check

Consider damage, heat, swelling, contamination or other abnormal behaviour.

Decision Normal or suspect?

Do not automatically return suspect batteries to the charging fleet.

Normal pathway Battery appears suitable for normal use

Continue according to the battery and charger manufacturer's normal operating instructions and the site's charging procedure.

Separate pathway Battery is damaged, abnormal or uncertain

Stop the ordinary charging process and follow the site's defined isolation, escalation and assessment procedure.

Explore damaged battery isolation
04
Supervision & charging periods

Consider what changes when everyone leaves the building.

A charging arrangement that is continuously visible to staff is operationally different from one that continues through evenings, nights or weekends.

The site should know when charging takes place, who is present during those periods and how abnormal conditions would be recognised when the area is unattended.

Occupied charging People are routinely present

Staff may be able to recognise unusual heat, smell, noise, smoke or charger alarms as part of normal supervision.

Periodically checked Charging is not continuously observed

Define who checks the area, how frequently and what they are expected to look for.

Unattended charging Charging continues after staff leave

Consider how detection, alarm communication and escalation remain effective when nobody is nearby.

Practical interpretation “We charge overnight” is an operating condition — not just a scheduling decision.

Unattended charging can change the importance of detection, notification, containment and the location of the charging activity.

05
Heat, ventilation & monitoring

Plan for the heat produced by normal charging — and for abnormal change.

Batteries and chargers can generate heat during normal operation. Dense charging arrangements should therefore be assessed for charger spacing, heat accumulation, ventilation and any manufacturer limits that apply to the equipment.

Where monitoring or alarms are provided, understand what they actually detect and what happens after a threshold is reached.

Normal heat Can heat dissipate during routine charging?

Consider charger density, enclosure arrangement, ventilation and manufacturer temperature limits.

Temperature monitoring What is being measured?

Cabinet air temperature, charger area temperature, individual battery temperature or another condition.

Smoke / gas / other detection What condition starts the alarm?

Understand the detection method rather than assuming all monitoring systems provide the same capability.

Notification Who receives the alarm?

Local sounders, building alarm systems, remote monitoring and after-hours communication may perform different roles.

Power response Does the system change the charging state?

Determine whether charging continues, disconnects automatically or depends on manual intervention.

Escalation What happens after an alarm?

The site's procedure should define who responds and how the situation progresses into the emergency plan.

When evaluating charging equipment Ask what the monitoring feature actually does.
Detects what? At what threshold? Sends what alarm? To whom? What action follows?
06
Operating procedure

Make the charging process repeatable.

A defined charging process reduces dependence on individual habits. Staff should know which batteries may be charged, where they go, what equipment is used and what should happen when something is wrong.

01 Receive battery

Battery returns from use or enters the charging process.

02 Check condition

Identify obvious damage or abnormal behaviour before connection.

03 Match charger

Use charging equipment appropriate for the battery.

04 Position correctly

Maintain the intended charging arrangement and avoid obstructing airflow or access.

05 Charge

Follow the defined charging period and supervision arrangement.

06 Return to service

Move charged batteries into the site's ready / stored inventory.

Exception Something appears abnormal

Stop the normal sequence and enter the site's isolation and escalation process.

A useful procedure should answer
  • Who is authorised to charge batteries?
  • Which chargers may be used?
  • Where may charging take place?
  • When may charging take place?
  • How are batteries checked before charging?
  • What happens when a battery or charger is damaged?
  • Who responds to alarms or abnormal conditions?
07
Abnormal behaviour

Define the point where normal charging stops.

Staff do not need to diagnose battery chemistry or internal failure mechanisms to recognise that something has changed. The charging procedure should make it clear when a battery or charger leaves the normal operating pathway.

Visual change Swelling, deformation or physical damage
Temperature Unexpected or unusual heating
Sound Unusual hissing, popping or similar abnormal noise
Odour / vapour Unexpected smell, smoke or visible venting
Charger behaviour Repeated faults, damaged charger or abnormal charging indication
History Impact, immersion, overheating, recall or uncertain condition
Normal process Charge → store → use
Abnormal condition Stop the normal charging pathway
Site process Isolate → escalate → assess
Emergency situations An actively developing battery incident is different from routine damaged-battery handling.

Sites should have an emergency plan appropriate to their battery activity, occupancy and building systems. Do not assume routine handling equipment is appropriate for an actively developing incident.

Charging-area review

Seven questions worth answering before you consider the equipment.

01 What batteries are being charged?
02 Are the chargers appropriate for those batteries?
03 What is the maximum simultaneous charging load?
04 Where does charging take place and what surrounds it?
05 Is charging supervised, periodically checked or unattended?
06 How are abnormal batteries removed from normal charging?
07 How would an abnormal condition be detected and escalated?
Battery + Charger + Electrical supply + Location + Supervision + Response = Charging strategy
Considering dedicated equipment? Move from the operating requirement into the charging solution formats.
Need help defining the charging requirement?

Tell us how your batteries are actually charged.

Battery Safe Systems can use the battery inventory, charger types, simultaneous charging quantity, operating hours and site conditions to help narrow the appropriate solution approach.

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