With lithium-ion batteries like those used in STIHL cordless tools, correct handling is crucial to a long service life so it’s worth knowing the ideal storage and care procedures.
It used to be that when a battery was put into long-term storage it had to be charged first, because all batteries were prone to high self-discharge which could result in irreversible damage such as heavy capacity loss or even unusable batteries.
Today, battery technology uses lithium-ion as standard, and these cells experience negligible levels of self-discharge. To protect cells from over-discharge a lithium-ion battery is usually built with separate integrated fuses that can automatically switch a highly discharged battery to a rest state so they don't need to be fully charged before storage. In fact, lithium-ion battery life is extended if it goes into storage partly charged – that said, it’s worth remembering that cells are negatively impacted in the event of storage with a very low level of charge or if the battery is fully charged. We recommend that you store a lithium-ion battery with two lit LEDs, indicating a charge of 40-60%, to minimise ageing and self-discharge.
Older battery types such as nickel-cadmium batteries (NiCd) or lead batteries used in motor vehicles have high self-discharge rates, and so if a battery has not been used for a long time, it may be prone to over-discharge. This is when the battery charge level falls below the cut-off voltage. When this happens energy can no longer be supplied and the battery may fail to charge. That’s why battery care advice used to specify fully charging before any lengthy storage period, as well as regularly checking the remaining charge.
STIHL batteries rely on lithium-ion cells and feature exceptionally low self-discharge rates of just 1-3% per year of storage. In addition, all STIHL batteries include an intelligent battery management system known as BMS. This monitors the voltage in each cell integrated into a battery, and in doing so prevents over-discharge: if voltage in the lithium-ion battery cells falls too far, the battery automatically switches to rest state, and the discharge process is interrupted.
This also happens during lithium-ion battery storage and when unused for long periods, meaning that you no longer need to worry about your battery being damaged by over-discharge.
Store the power tool at low, frost-free temperatures. Avoid storage in direct sunlight and damp conditions. Further information on the storage temperature for your power tool is available in the instruction manual. For safety, we recommend storing the activation key separately from the cordless power tool.
If you are using your cordless power tool with integrated battery after a lengthy storage period, charge it just before you use it. This safeguards the capacity and has a positive effect on the service life. The battery will only charge at temperatures above 5°C; the charger monitors the battery temperature and prevents charging if the temperature is too low or too high.
Every STIHL cordless power tool uses a cutting-edge lithium-ion battery because it is lightweight and quiet, but also offers high energy and power density. They have a long lifespan, although they will need to be replaced eventually.
We recommend that you do not store STIHL batteries fully charged, but with two green LEDs – 40-60% charged. At this charge level the battery can stay unused in storage for two years with no damage, and with a minimal amount of self-discharge. You only need to charge your battery shortly before use. Batteries must always be charged at a temperature above 5°C.