FAQs

Frequently asked questions of corded&cordless power tool electric tools

Questions and answers on core drilling

How can I prevent the core bits from becoming blunt or overheating when drilling?
Remember good lubrication is essential. Optimal results can be gained with internal cooling via the core bit with a standard drill emulsion.

What should I do if the core bit is chattering?
Check whether the core bit is still sharp.
The guides must be set to have no play on the machine. If this isn't the case, please send your tool to customer service.
Carefully increase the feed force until the chattering decreases or change the speed if possible. Use caution as too much feed force may result in the tool lifting up.

What do I need to change if core bits are breaking?
Check whether the core bit is still sharp.
The guides must be set to have no play on the machine. If this isn't the case, please send your tool to customer service.
Reduce the feed force and change the speed if possible.

How should the tool be set up?
The surface being worked on must be clean and free of rust, scale or paint.
The entire magnetic foot must sit on the material to be drilled.
The material must be at least 12 mm thick and magnetisable.

What problems can occur, if one or more of the above requirements are not fulfilled?
The result could be the machine moving on the material causing cutter breakage.

What should I do if the material isn't magnetisable or is thinner than 12 mm?
You'll need a vacuum plate and pump, or a suction plate. These items are described in the catalogue.

Why should I use a centering pin?
To find the exact centre of the drill hole
To eject the slug.

What should I note when drilling?
Position the drill with care and drill through in one go wherever possible.
Don't switch the tool off during drilling, as doing so could cause the core bits to break loose.
Before the drill is withdrawn from an incomplete hole, let the tool run for a short time at the bottom of the hole without removing any material. This will break the chips forming at the bottom of the hole.
Always withdraw the drill from the hole with the tool running clockwise.

What action should I take if the core bit gets stuck?
Switch off the motor. Inspect and carefully take the appropriate action to remove the cutter.

What problems can be experienced with core drilling?
High temperatures near welded seams or separating cuts made by cutting torches may result in structural changes, which can cause the core bit to wear very quickly.
In the case of overlapping holes, the core bit may catch at the transition between the existing hole and the new one, causing the core bit to jam or even break.

What is the proper way to store and transport core drills?
Store and transport the core drill in its original packaging or at the intended position in the transport box.
Core drills should be protected from impact, to prevent damage to the core drill or cutter.

Questions and answers on battery care

How should I store my batteries?
NiCd / NiMH batteries should only be stored for long periods in a fully charged state. Recharging is needed at least every 3 months as the batteries will self-discharge. Lithium-ion batteries shouldn't be stored flat or fully charged for long periods. Extensive testing has found a capacity of 40...50 % and low temperatures (but not below 0°C) to be optimum for storage. Ideally they should be kept at 5°C to 10°C. Recharging is needed at least every 12 months as the batteries will self-discharge.
If you are not going to use it for a long time, should you remove the battery from the tool?
Yes. Even when the device is switched off, a little current may flow which over time will result in total discharge. This will damage and in extreme cases destroy the battery.

What is self-discharge?
Due to self-discharge, if not used for 3 months an NiCd/NiMH battery will lose around 60...80% of its charge. The figure for lithium-ion batteries is 3...5% a month. Self-discharge is temperature-dependent and increases with temperature, with room temperature being ideal.

What is total discharge?
Total discharge means squeezing out the last drop of current from a battery. The battery's voltage then falls to 0 V. If this status is maintained, chemical reactions occur at the electrodes in the battery which render them partially or totally unusable. As a result, the battery loses huge amounts of capacity and in extreme cases cannot be charged any more. You must therefore avoid discharging batteries below a type-dependent final discharge voltage and then recharging them as quickly as possible. Lithium-ion batteries and lithium-ion polymer batteries should never be totally discharged. As a rule of thumb, you should recharge a lithium-ion or lithium-ion polymer battery when it still has around 10...20% of its capacity. Good Li-ion batteries always have elaborate protective and/or monitoring circuits in the battery pack to prevent total discharging / overcharging and the possibility of explosion.

Within what temperature range should I use my batteries?
NiMH batteries are not suitable for use at temperatures below 0°C. They show signs of significantly reduced capacity even at close to freezing point and are totally unusable below around −10°C. NiCd batteries are suitable for use down to -10°C. Lithium-ion batteries can be used in a temperature range of between -10 °C and +55 °C, but should only be charged at a battery temperature of +5...+45°C. The ideal battery temperature range is room temperature. A temperature sensor in the battery ensures that rapid charging does not occur outside this range.

What is the battery service life?
NiMH batteries can be charged 400 to 700 times, NiCd batteries around 500 to 1,000 times and Li-ion batteries up to 1,000 times (depending on capacity). These figures are however only attained under optimum conditions. Depending on how the battery is treated and cared for, lower figures may apply. Battery capacity decreases over the battery's life. Batteries with less than 70% nominal capacity are generally considered to be worn out.

What does memory effect (for NiCd technology) or lazy battery effect mean?
The battery records how much it has been used. If the battery isn't fully discharged before charging, small crystals form on the electrodes and make it harder to charge. If you fail to fully discharge the battery several times in a row, you will experience shorter and shorter availability times. With NiMH technology, you might experience a lazy battery effect, similar to the classic memory effect. Lithium-ion batteries and lithium-ion polymer batteries can and may be recharged at any time. These batteries do not experience any kind of memory effect, but you should avoid charging for short periods too often. Fully charging in several stages (with or without partial discharge in between) is also not harmful. Lithium-ion batteries and lithium-ion polymer batteries should not however be fully discharged. As a rule of thumb, you should recharge a lithium-ion or lithium-ion polymer battery when it still has around 10...20% of its capacity. A new lithium-ion battery does not have to be charged and discharged several times to attain its full capacity. If the initial charge is undertaken correctly, the battery will have a full capacity from day one. Do not attempt to force more charge into a full battery block by unplugging and reconnecting the charger - it will only damage the batteries.

Can I reverse these effects?
If the capacity of the NiCd battery decreases over time, it can be restored by reconditioning: fully discharge NiCd battery (don't go quite as far as total discharge) (by loading, i.e. in use), fully recharge and repeat several times. Each time this cycle is repeated, it improves the power output. A refreshing device is needed for NiMH batteries.

Can batteries be repaired?
Batteries cannot be permanently repaired to a high quality. Even if other providers claim that they can repair batteries cheaply, the results will be short-lived because the new cells are not matched to existing components. FEIN and its agents offer long-term quality. We always replace defective batteries.
The following rules should be noted when caring for your lithium-ion batteries if you want to maintain the performance of the energy store for as long as possible:
The first charge is crucial. Fully charge the battery before using it for the first time.
Each battery only has a limited number of charge cycles. Don't therefore recharge the battery at every opportunity. Instead use it until it is almost flat (10...20% of charge).
If the battery is discharged below its nominal voltage, this can trigger processes which damage or destroy the battery. FEIN batteries are therefore fitted with electronics which warn the user and shut down the device before total discharge can take place.
Frequent overcharging can also permanently damage the battery. The charger therefore automatically finishes the charging process as soon as the battery is fully charged.Do not attempt to force more charge into the batteries by unplugging and reconnecting the charger. Such action will not produce a higher charge - it will only damage the batteries.
Charging should generally only be undertaken at room temperature (around 18 - 21 degrees). Avoid charging a cold battery as it damages the cells. Always warm the battery up to room temperature before charging, especially when it is cold outdoors in winter.
High temperatures also damage the battery. Never leave the battery, and preferably not the entire tool box, in the car or direct sunlight on hot sunny days. At temperatures above 60 degrees Celsius, the Li-ion battery permanently loses capacity.
Lithium-ion batteries shouldn't be stored flat or fully charged for long periods. Extensive testing has found a capacity of 40...50 % and low temperatures (but not below 0°C) to be optimum for storage. Ideally they should be kept at 5°C to 10°C. Recharging is needed at least every 12 months as the batteries will self-discharge.
A battery which is not being used should be stored in a cool but not cold place. Even when not being used, batteries lose energy. The Li-ion battery loses 3...5% of its charge a month.
If a lithium-ion battery is not used for a long period, it should be recharged after 12 months at the latest otherwise it will be irreparably damaged.
Old, used batteries must of course be disposed of in an environmentally friendly manner.