Rechargeable batteries-FAQs

FAQ – Frequently asked questions

STIHL Cordless Power Systems

How long is the service life of rechargeable batteries?

The service life of rechargeable batteries cannot be generalized because it depends on:

  • proper use of the battery
  • care and storage of the battery
  • the number of charge cycles (a charge cycle is a full charge from 0% to 100%)
  • natural aging of the lithium-ion cells over time

For example, STIHL batteries in the PRO cordless system can be fully recharged up to 1200 times.

 

PRO cordless system usage scenario

Professional Private User
Charge cycles
per year

2 charge cycles per work day
= 440 charge cycles per year*

10 charge cycles per month
= 120 charge cycles per year 

Time required for
1200 charge cycles:


about 2.5 years**


about 10 years**

* assuming 220 work days
** assuming the battery is always used, maintained and stored correctly

What are the benefits of the 36V technology?

The quoted voltage alone says nothing about the power of the batteries or the cordless products.

Power is defined as the product of voltage and current:
Power = Voltage x Amperage --> W = V x A

The interaction between voltage and current and the technical implementation of the overall system are the points that determine the performance of a cordless product.

In the case of hand-held cordless battery products, a compact build and weight are crucial for operator convenience. From a technical point of view there are certain restrictions when it comes to making products compact:

  • One goes for a high voltage (e.g. 80V) and can technically use only low electrical currents because the number of components and the weight would otherwise increase.
  • On the other hand, one confines oneself to a still meaningful high voltage (36V), which allows high electrical currents technically and can limit the number of components and the weight.

STIHL, like many other established manufacturers of cordless battery products, decided in favor of a system with a maximum voltage of 36V. This high voltage, which is still technically meaningful and allows high electrical currents to be used, guarantees high performance and future sustainability of the cordless products.
Cordless products are compact, lightweight and more robust due to the use of fewer electrical components.

Furthermore, STIHL offers an efficient, high-performance overall system of matched components:

  • The intelligent motor control guarantees constant high power over the entire running time.
  • The energy supply to the electric motor is actively controlled in response to the type of application. Full power is always made available for extreme applications. However, power is automatically reduced if it is not necessary for the current application. In this way the energy in the battery is used optimally and the runtime on a single charge extended.
  • Efficient batteries in compact design and available in different versions (with high energy content or low weight) ensure a long runtime and operator convenience.
  • Cutting attachments designed to match the cordless product, e.g. the ¼" P saw chain, guarantee optimum performance in every application.

Ultimately, it is always the energy content of the battery and the efficiency and implementation of the overall system that define the runtime and performance. For this reason systems with 56V or 80V have no advantages over the STIHL cordless system with 36V.

How high is the power of cordless battery products compared to gasoline products?

STIHL offers products with different types of drive. Corded and cordless electric products as well as classic gasoline products.

Performance specifications and the methods of determining power differ between the types of drive:

  • Gasoline: The mechanical output power is quoted
  • Electric: The electrical power consumption (nominal value) is quoted

These power specifications have become established for the two types of drive, but as they differ they cannot be compared directly with each other. That means therefore: A comparison of performance, e.g. between a gasoline chainsaw and an electric chainsaw, is not possible, nor is it meaningful.

The comparison is even more difficult with cordless battery products. In this case manufacturers have not yet established a standard way of specifying power.
The situation is further complicated if one wants to compare cordless battery products with gasoline products because of the differences in behavior during operation. For example, the cordless product’s electric motor produces high torque even at low RPM. In difficult situations, e.g. when the cutting attachment becomes slightly pinched, the cordless product feels more powerful than a comparable gasoline product and does not jam as quickly. A comparison would therefore have little meaning and cannot reflect the perceived power available in different working situations.

How are batteries protected against thermal and energy-related influences?

Current and voltage monitoring

  • Reducing motor RPM if the cutting attachment is blocked

Temperature monitoring

  • Signal and automatic shutdown in case of too high a temperature

Voltage monitoring of individual cells

  • No overcharging possible during charging
  • No exhaustive discharge possible during operation

Charge

How long does it take to recharge batteries?

For the charge times of STIHL batteries and STIHL cordless products with built-in batteries visit www.stihl.com/charging-times.

What do the 80% and 100% charge times mean?

The specifications 80% and 100% refer to the battery’s state of charge. The corresponding charge time indicates how many minutes it takes for a flat battery to reach that state of charge.

About one third of the charge time is required for the last 20%. The reason for this is that the battery cannot be recharged up to 100% at a constant high charging current.
The charging current drops continuously towards the end in order to protect the cells and retain their performance over many charge cycles. Therefore, a relatively long period is required to charge the last percentage of capacity.

It is possible to work with STIHL cordless products and use full power even if the battery is not fully charged.

What points have to be observed during the battery charge process?

The battery can be charged at any time regardless of its state of charge, e.g. during a work break. There is no memory effect, i.e. the battery can be taken out of the charger even before it is fully charged.

  • Charge the battery in a dry and enclosed location at an ambient temperature between +5°C and +40°C.

Does the use of a quick charger harm the battery in the long term?

The use of a quick charger has no detrimental effect on the useful life of the battery.

The battery and charger are intelligently connected during the entire charge process. Both components jointly determine the optimum charge process and are monitored by the battery management system. This avoids the cells in the battery being damaged by excessively high charge currents and temperatures.

Is it normal that the battery and/or charger become hot during the charge process?

The temperature of the battery and charger increases during the charge process.

The temperature is monitored over the entire charge process. If the temperature rises above a certain limit, the charge process is automatically interrupted until the temperature drops to the approved level. The charge process is then continued automatically. This avoids the battery and charger overheating.

The AL 300 and AL 500 chargers are equipped with a fan which is switched on and off automatically to actively cool the charger and battery during the charge process. The fan runs continuously on first generation chargers.

Maintenance, Care, Storing

What points must be observed when servicing and maintaining batteries?

STIHL batteries do not require servicing.
A dirty battery housing should be cleaned with a damp cloth.

What points must be observed when storing batteries?

Check the following points when storing the battery:

  • Battery is out of the reach of children
  • Battery is clean and dry
  • Battery is in an enclosed location
  • Battery is stored separately from the product and charger
  • Battery is in non-conductive packaging
  • Temperature range for AK, AP, AR batteries: -10°C to +50°C
  • Temperature range for products with built-in battery: 0°C to +50°C
  • Temperature range for battery in HSA 25: 0°C to +40°C

Why should the battery be stored with a charge between 40% and 60%?

STIHL recommends that the battery or product with a built-in battery be stored with a charge between 40% and 60% (2 green LEDs glow) if it is not used for more than 1 month. This avoids exhaustive discharge during storage over a period of several years. In addition, the natural aging of the lithium-ion cells is minimized and that has a positive effect on battery life.

Can the battery be exhausted during storage?

Yes, the battery can theoretically suffer from exhaustive discharge during storage. The self discharge rate is about 1% to 3% per year.

STIHL recommends that the battery or product with a built-in battery be stored with a charge between 40% and 60% (2 green LEDs glow) if it is not used for more than 1 month. This avoids exhaustive discharge during storage over a period of several years. In addition, the natural aging of the lithium-ion cells is minimized and that has a positive effect on battery life.

Does the battery have to be recharged during storage?

The battery does not need to be recharged during storage if it is used regularly.
Even a flat battery can be stored for several months without being damage by exhaustive discharge.

STIHL recommends that the battery or product with a built-in battery be stored with a charge between 40% and 60% (2 green LEDs glow) if it is not used for more than 1 month. This avoids exhaustive discharge during storage over a period of several years. In addition, the natural aging of the lithium-ion cells is minimized and that has a positive effect on battery life.

Application

How much can be done on a single charge (cuts in wood, sq.m lawn, etc.)?

Click on the table images to get an enlarged view.

¹ Guide values which may vary depening on material being cut.

¹ Guide values which may vary depending on material being cut.
² Reduced machine performance.

Normally, the products in the PRO cordless system have a longer battery runtime compared to products in the COMPACT cordless system because the STIHL AP and STIHL AR batteries generally have a higher energy content.

The main aim when working with products in the PRO cordless system is efficiency and job progress. Owing to their high performance, the products get more done in a much shorter time.

How long are the runtimes of the cordless battery products?

For the runtimes of STIHL cordless battery products visit:
www.stihl.co.nz/static/stihl-accu-advisor/index.html

Why can one work for longer with a STIHL AR battery than with a STIHL AP battery?

The batteries have different energy contents. This is determined by the number of cells used, the voltage of the individual cells and the available charge of the individual cell. The higher the energy content of a battery, the longer the runtime of the cordless product.

For this reason a cordless product with a STIHL AR battery can be operated for much longer than with a STIHL AP battery.

In what temperature range may the battery be used?

Batteries may be used within the following temperature range:

  • STIHL AK , AP, AR batteries -10 °C to +50 °C
  • Products with built-in battery: 0 °C to +50 °C
  • Battery of HSA 25: 0 °C to +40 °C

May cordless products be operated in the rain or wet conditions?

* Observe information in instruction manual for STIHL AR battery and STIHL ASA pruning shears. The STIHL KGA cordless sweeper is not suitable for use in the rain or wet conditions.

How does the salty air on the coast affect the battery and cordless product?

Salty air can have detrimental effect on the life of the battery and the cordless product. The effects can differ according to the length of usage and the salt content in the air.

In order to counteract corrosion of the electrical contacts, store the battery and cordless product as follows:

  • Store the battery and cordless product in a clean and dry condition
  • Store the battery and cordless product in an enclosed location
  • Store the battery separately from the cordless product and charger in non-conductive packaging

Purchase

What are the points in favor of buying a cordless product?

STIHL cordless products are distinguished by the following features:

  • They are easy to start
  • They are quiet and can also be used in noise-sensitive areas
  • They are lightweight
  • They produce no emissions
  • There is no need to handle fuel
  • Cordless products are robust and require little maintenance
  • The modular system enables one battery to be used for several cordless products
  • Normally, hearing protection is not necessary during operation
  • As a rule, the vibrations that occur and the loads on the user during operation are low.

* Observe information in instruction manual for cordless product.

How high are the costs of purchasing and running cordless products compared to gasoline products?

The purchase price of a cordless product, including a battery and charger, is often higher than the cost of a comparable gasoline product. However, one has to take into account that the running costs are much lower since no fuel or spark plugs are required for operation.

Assuming proper use, the high performance, longlife batteries ensure that the break even point is definitely reached during the product’s life. The question as to exactly when this point is reached depends on a number of factors, e.g. the cordless product, the type of usage, user behavior, the costs of fuel and the cutting attachments used.

Buying additional cordless products in the same STIHL cordless system improve the calculation still further because the costs for battery and charger are saved. The modular concept allows batteries that have already been purchased, and the charger, to be used for all other products in the same cordless system.

Why are the prices of cordless products so high?

STIHL offers a broad range of cordless products in different price categories – from the attractively priced STIHL lithium-ion cordless system for use in small gardens and around the house to the STIHL PRO cordless system for professional users.

In principle, all STIHL batteries and STIHL cordless products are manufactured to a high quality and ideally rated for the respective usage scenarios and target groups.

After the initial purchase, the purchase of further products in the same cordless system becomes even more attractive. The modular concept allows batteries that have already been purchased, and the charger, to be used for all other products in the same cordless system. Compared to gasoline products, there are no costs for fuel or spark plugs.

For how long does the warranty apply?

Warranty terms are country-specific and can be obtained from Local STIHL representative.

What points must be observed when disposing of the batteries?

Information on disposal is available from STIHL servicing dealers.

  • Dispose of batteries in accordance with local regulations and environmental requirements.