A projects can be stopped quick if a cordless drill stops working in the middle of a crucial screw. You might be balanced on a ladder somewhere with drywall dust in you eyes when the drill’s trigger will not deliver the power required to continue. The battery that once delivered power like a perfect symphony may feel as heavy as a brick in your hand.
This problem can afflict weekend warriors using cordless drills and professionals using cordless drill alike. Battery problems is insidious and develop in quiet unnoticeable ways. Yet, there are changes in battery performance that you can recognize and understand.
Once you recognize the symptoms of failing cordless drill batteries, you will begin to understand how to fix them. Most battery problems have a cause and solution, and there are very few issues with cordless drill batteries that are not fixable. Whether you have a compact 12-volt cordless drill or a heavy-duty 20-volt cordless drill there will be very few issue that are not fixable with some knowledge of how to correct them.
Common Problems With Cordless Drill Batteries
1. Battery Will Not Hold a Charge
The first of the many battery problems that can occur with cordless drills is that the battery will not hold a charge. If you find that your battery will charge overnight but will be dead in the morning then you have one or two dead cell in the battery pack. If any lithium-ion battery cell drop below the voltage needed to power the drill then the battery will refuse to hold a charge.
If the battery pack will not hold a charge then the battery will not start up with the charger attempting to initiate the battery pack. There are fixes for this problem. Depending upon your level of handy skills you can either buy a replacement cell kit for your battery pack to rebuild the battery or you can simply purchase a new battery pack.
In the mean time, before purchasing a new battery pack, try placing a known good battery pack into the drill for thirty seconds to jump start the failing battery pack so the dead cells rise above the voltage needed threshold to start the battery pack. This trick will work and will allow you to shop for new batteries at the next hardware store run.
2. Battery Failure Due to Heat
The next problem with cordless drill batteries is that they fail due to heat.
If you find that your battery gets very hot when you use your cordless drill heavily then the chemistry of the battery is being stressed. Most lithium cells cannot stand temperatures above 110 degrees Fahrenheit. This is true when charging the battery pack and when the battery is under heavy use.
Excessive heat can break down the chemicals in the battery, form metallic dendrites on the electrodes, and permanently reduce the capacity of the battery pack. The causes of this problem are also simple. Using a small drill to perform heavy jobs can produce heat due to the chemistry of the battery working harder than it should.
Another cause of heat in the battery is leaving the battery in the hot truck bed or allowing the battery to be charged in direct sunlight. In order to fix this problem require a change in the way you use your drill and charge your battery. Limit the size of the drill to the size of the job and take breaks in the job to allow the battery to cool. Store your battery at room temperature when possible. Following these suggestions will immediately improve the runtime of your cordless drill batteries and will improve their life.
3. Voltage Sag Under Load
The third problem with cordless drill batteries is voltage sag under load.
Even if your battery pack reads three bars of charge the drill will not have enough voltage to complete the job. As the cells age the chemical layers within the battery thickens and creates resistance to the passage of electrons. This problem generally develops in older high capacity battery packs.
These type of battery packs have more cells in parallel and there are more opportunities for voltage to drop due to the resistance within the chemical layers of the cells. To fix this problem change to a lower capacity battery pack that is newer. The smaller battery will have less resistance in its chemical layers and will provide enough voltage to power the drill.
The smaller battery may cost more money up front but over time you will save money due to the increased life of the battery. Also, the voltage will remain stable under load and will power your drill consistently.
4. The Memory Effect Myth
The fourth problem with cordless drill batteries is that they succumb to the memory effect.
This is a myth for lithium batteries yet many users continue to charge their batteries top off after every few minutes of use. The best way to maintain the life of the battery is to allow it to fully discharge every few months. This will recalibrate the battery and ensure the battery pack reads the same as the amount of power it actualy contains.
Try one battery every month until it fully discharges. After the battery fully discharges place it onto the battery charger and allow it to reach 100% charge without interruption. You will notice that the runtime of the battery will match the cordless drill fuel gauge.
This is simply the battery pack’s protection circuit remembering the zero level of battery drain.
5. Corrosion on Battery Contacts
Another problem that can plague users is corrosion on the battery contacts. These contacts can accumulate a white or green fuzz due to the exposure of the metal to moisture or the years of exposure to dust and body oils.
If the fuzz coats the drill’s contacts the battery may suddenly stop working. Cleaning the contacts with a pencil eraser or isopropyl alcohol will fix the contact problem. Do not use sandpaper as this will remove the metal plating from the contacts and the contact problem will reoccur.
After reapplying a small dab of dielectric grease to the contacts the battery will have improved performance.
6. Swollen Battery Pack
Another very scary problem with cordless drills is a swollen battery pack. Swollen battery packs have a plastic case that bulges out of the battery indicating that gas has entered the battery.
This results from overheating or overcharging the battery. The chemical cells are compromised and if you use the battery more you risk starting a battery fire. If the battery pack is swollen the only way to fix the battery is to recycle it.
Most big box stores have battery recycling bins located at the front of the store. Do not attempt to open or puncture the battery. A lithium battery fire is hard to extinguish and the smoke created by a battery fire is toxic.
Do not risk your life starting a fire that will damage your home and hurt your health. This is a signal from the chemical of the battery that it has reached the end of its life and you should move on from using this battery.
7. Charger Circuit Board Failure
Finally, sometimes you may find that a battery pack is working fine one day then the next day when you try to charge it the battery will not take a charge.
This is mostly due to the failure of the charger’s circuit board over time with use and exposure to the elements. Try the battery pack in a different charger and test the suspect charger with a good battery pack. You will save money buying a new battery if you test the charger.
The best care for your cordless drill batteries requires you to respect a few simple facts. Do not expose your drill batteries to excessive heat. Use your batteries consistently but moderately.
Fully discharge your batteries at least once every few months. If you treat your batteries this way they will be ready when you need them the most. This is the difference between buying a new battery every few months and using your drill batteries for years of reliabel service.
