What kills power tool batteries fastest?

Excessive heat is the primary cause of premature lithium-ion battery failure. Storing packs inside hot vehicle toolboxes, leaving them in direct sunlight, or charging them immediately after heavy discharge degrades internal cells rapidly. Deep discharging cells to zero per cent and prolonged moisture exposure also permanently diminish runtime and overall cycle life.

How should I store power tool batteries long-term?

Store power tool batteries in a climate-controlled, dry space at roughly fifty per cent charge, or two bars on the fuel gauge. Never store packs fully depleted or at one hundred per cent for extended periods. Extreme temperatures inside uninsulated metal sheds accelerate chemical degradation and parasitic drain over time.

Can you leave cordless tool batteries on the charger?

Modern smart chargers stop current once packs are full, but leaving batteries plugged in continuously is not recommended. Sustained trickle maintenance can stress cells if ambient temperatures rise. Remove packs promptly once the green status indicator shows fully charged, and store them on a cool, shaded shelf.

How do you safely dispose of dead power tool batteries in Australia?

Never dispose of lithium-ion tool batteries in regular kerbside rubbish or standard recycling bins due to severe fire risks. Tape the battery terminals with clear packing tape and drop them off at authorised B-cycle collection points nationwide, including participating retailers like Bunnings, Total Tools, and Sydney Tools.

Should you let a hot tool battery cool down before charging?

Yes, always allow hot battery packs to cool down to ambient room temperature before placing them on a charger. Charging a hot lithium-ion cell causes thermal stress, triggers internal safety cut-offs, and significantly shortens operational lifespan. Quality rapid chargers will often delay the cycle until the pack cools sufficiently.

What is the typical lifespan of an 18V lithium-ion battery?

A trade-grade 18V lithium-ion battery typically lasts between three and five years, or roughly one thousand charge cycles, under normal use. Longevity depends heavily on operating temperatures, tool load, and charging discipline. Packs subjected to sustained overload, poor storage, or high heat degrade significantly faster.

Make Your Tool Batteries Last Years Longer

Maximise power tool battery life with proven charging, storage, and cooling habits. Learn how to protect your cordless packs and recycle dead cells safely.

Quick answer

Power tool batteries last significantly longer when protected from high heat and kept between twenty and eighty per cent state of charge. Avoid charging packs immediately after heavy use while cells remain hot. Store batteries in a cool, dry location and recycle expired units at authorised B-cycle collection points.

Skill level: Buyer's Guide
Time: Varies
Trade: Plumbing
Updated: 4 November 2026

Tools you will need

Milwaukee M18 B5 - 5.0Ah Lithium-Ion Battery Pack
Makita BL1850B - 18V 5.0Ah Heavy Duty Battery
DeWalt DCB115-XE - XR Multi-Voltage Fast Charger
Hikoki UC18YSL3 - 14.4V-18V Rapid Charger with Cooling Fan
Fluke 117 - Digital Multimeter with Battery Test Function
Bostik Heavy Duty Clear Packing Tape - Terminal Insulation

On any cordless platform the batteries — not the tools — are what you keep replacing. Look after them and you push that cost years down the track. The habits are simple and cost nothing.

Heat is the number one enemy

Lithium-ion cells age fastest when they get hot. The single biggest favour you can do your batteries is keep them out of the heat:

Do not leave packs baking in a hot ute, cab or toolbox in the sun. A day in the heat repeated over a summer takes a real toll.

Let a pack that is hot from heavy use cool down before charging it.

Store batteries somewhere cool and dry, not on a sunny windowsill or the dashboard.

Charge and discharge habits

Avoid running packs completely flat and leaving them flat. Topping up before they are fully drained is easier on the cells than deep-discharging every time.

For long-term storage, aim for around half charge rather than dead flat or full. Check stored packs occasionally and give them a top-up if they have drifted low.

Take packs off the charger once full rather than leaving them sitting on a hot bench charger for days.

Handle them like they matter

Keep contacts clean and dry; moisture and grit cause problems.

Avoid drops and crushing — a physically damaged pack can fail or become unsafe.

Retire a pack that is swollen, damaged or behaving oddly rather than pushing it.

When a pack is done, recycle it safely

Every battery reaches the end eventually. When it does, never put it in a general or recycling wheelie bin — damaged lithium-ion cells are a genuine cause of truck and transfer-station fires. Instead, drop flat or dead packs at a free collection point through the national battery scheme, B-cycle. It is free, it is safe, and the materials get recovered.

Looking after your packs also protects the value of your whole platform, which you chose in Which Cordless Battery Platform Should You Commit To?. And when it is time to add capacity, How Many Tool Batteries Do You Actually Need? helps you buy the right packs rather than the biggest.

Old batteries and retired tools

Flat or ageing batteries still have value, and dead lithium-ion packs must never go in general or recycling wheelie bins — damaged cells are a genuine fire risk in trucks and transfer stations. Recycle them free through the national battery scheme at B-cycle drop-off points. When you are moving platforms, working "skins" (tool-only units) that no longer suit you can often be sold or traded rather than binned. Before you buy your next skin, it is worth knowing where tool prices are heading — our Tool Price Index tracks how cordless tool prices are moving.

Kitting out or upgrading a platform

Committing to a platform is a real investment, because the batteries — not the tools — are the recurring cost over the years. If you are setting up a new platform, replacing a stolen kit, or standardising your crew onto one system, spreading the cost with equipment finance can keep your working capital free for jobs and materials. It is worth weighing the repayment against the runtime and downtime you save. See how tool-and-equipment finance works for sole traders and small crews on our equipment finance guide.

Frequently asked questions

What kills power tool batteries fastest?: Excessive heat is the primary cause of premature lithium-ion battery failure. Storing packs inside hot vehicle toolboxes, leaving them in direct sunlight, or charging them immediately after heavy discharge degrades internal cells rapidly. Deep discharging cells to zero per cent and prolonged moisture exposure also permanently diminish runtime and overall cycle life.
How should I store power tool batteries long-term?: Store power tool batteries in a climate-controlled, dry space at roughly fifty per cent charge, or two bars on the fuel gauge. Never store packs fully depleted or at one hundred per cent for extended periods. Extreme temperatures inside uninsulated metal sheds accelerate chemical degradation and parasitic drain over time.
Can you leave cordless tool batteries on the charger?: Modern smart chargers stop current once packs are full, but leaving batteries plugged in continuously is not recommended. Sustained trickle maintenance can stress cells if ambient temperatures rise. Remove packs promptly once the green status indicator shows fully charged, and store them on a cool, shaded shelf.
How do you safely dispose of dead power tool batteries in Australia?: Never dispose of lithium-ion tool batteries in regular kerbside rubbish or standard recycling bins due to severe fire risks. Tape the battery terminals with clear packing tape and drop them off at authorised B-cycle collection points nationwide, including participating retailers like Bunnings, Total Tools, and Sydney Tools.
Should you let a hot tool battery cool down before charging?: Yes, always allow hot battery packs to cool down to ambient room temperature before placing them on a charger. Charging a hot lithium-ion cell causes thermal stress, triggers internal safety cut-offs, and significantly shortens operational lifespan. Quality rapid chargers will often delay the cycle until the pack cools sufficiently.
What is the typical lifespan of an 18V lithium-ion battery?: A trade-grade 18V lithium-ion battery typically lasts between three and five years, or roughly one thousand charge cycles, under normal use. Longevity depends heavily on operating temperatures, tool load, and charging discipline. Packs subjected to sustained overload, poor storage, or high heat degrade significantly faster.

Written by Pipey, the Plumbing specialist at Aus.Tools.