How To Charge A Cordless Drill Battery Without A Charger

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How To Charge A Cordless Drill Battery Without A Charger

 

The cordless drill is doubtless a staple in every toolbox, from homeowners to professional contractors.  The freedom of movement and angle it provides makes it a decisive improvement over corded drills with similar capabilities.  

It can even be enough to make some workers forfeit some power or bit width in return for being able to take the drill wherever they please without the inconvenience of being pulled over by a trailing extension cord. 

Especially with the advent of the interchangeable battery that many leading manufacturers now supply, the cordless drill is more attractive than ever. One simply slips the battery out of the jigsaw or sander and onto the drill, sparing the need for a proprietary charger.  And it creates more space in your toolbox with only one battery to worry over. 

Naturally, this added convenience brings with it an Achilles heel when a person finds they have a dead battery.  Without the continual current of a corded model there is only so long your drill can keep going. 

Many in the construction or repair field will carry several battery packs for just such an occasion. Others will try and bring their charger to work with them and plug in their first battery until it is once again ready to go. No one wants to get stuck without some way to get their drill working again. 

A charger is a piece of equipment just like any other equipment that will eventually wear out and stop working.  You can also find that the charger has been lost, stolen, or damaged, or anything else that makes your charger unuseable.  

Although most brands of charger are readily available as replacements, getting a new proprietary charger is often too costly and time-consuming to be bothered with.  Believe it or not, there are a number of alternatives to buying a new one. 

Your first preparation step should be to determine the voltage of the battery to be charged and which terminals are positive and negative.  These steps are short and easy but essential to prevent the many serious malfunctions that can accompany an improper charge. 

Connecting your battery the wrong way around or charging with the improper voltage can permanently damage the battery’s function.  You run the risk of cracking or warping the casing, causing a leakage of the battery elements, or the battery could explode or ignite. 

With these preliminary steps completed, the next step is the creation of a power supply.  Electricity needs to come from somewhere, and in this case that will be other batteries linked to the drill battery. 

Although it may be tempting to connect the battery to a power main, this is inadvisable at best.  A power main gives you no control over the power supply. Without proper preparation this resources requires more specialized equipment than is generally found at a work site. 

To avoid any complications and risks associated with utilizing higher voltages, this method uses ordinary AA batteries (1.5 volts) linked in series.  This is easiest to do with duct tape keeping the smaller batteries in a line that keeps the positive terminal of each pressed to the negative terminal of the next. 

Assuming we are working with a standard 12-volt drill battery, roughly 8 to 10 smaller batteries may be needed.  This number can be varied depending on how many volts the battery you plan to charge draws and what batteries you are using as your power source. 

 

How To Charge A Cordless Drill Battery Without A Charger

 

As this is effectively meant to create a single long battery, it is crucial that there be no gaps between smaller batteries. Spaces between the batteries will mean that the circuit is incomplete and ineffectual. 

It is possible to use small amounts of tin foil or other conductive material to fill the gaps and ensure that there are no breaks in the long battery, albeit with caution due to several connected and live batteries. 

With the body of your long battery assembled, you can create two terminals by attaching pieces of wire to the ends with electrical tape.  Choose insulated wire to prevent untoward connections.

Then expose enough of the ends to apply firmly to the terminals on your drill battery. One connected, these wires conduct the full charge of the batteries between them, so be careful what they touch and when. 

Attach the exposed ends of the wires to your drill terminal with electrical tape to begin the charging process.  Unlike when using a battery, where negative is connected to positive, you will want positive to positive in this case, and negative to negative as well. 

It may take slightly longer than an ordinary charger, but if properly calculated, this method will charge your battery without overcharging it. 

Although we have used AA batteries for this example, any will do.  Simply calculate the voltage and make sure to use conductors that can handle the charge moving through them. 

As long as the correct procedure is followed, it is realistically possible to charge a drill even from another drill.  The principles at work remain and function the same way. 

This method is recommended only for those experienced on the work site and with thorough knowledge of the field of rechargeable batteries.  For safety reasons, anyone not entirely confident in their ability to execute the procedure outlined here is best advised to delay their work until they can retrieve or acquire  a working charger. 

Even among the most experienced of machinists, there are some precautions to be taken before and during this process.  Make certain the battery is fully drained and disconnected before setting it up to recharge. Avoid touching the terminals with bare skin or conductive items. 

At all stages, be alert for the components heating up, smoking, or emitting unusual odors or substances.  Any of these could be a sign of a dangerous error in the construction of your charging array. Should any of these appear, disconnect and separate all elements, and do not use them again until they have been carefully determined to be safe and functional.