Your cordless drill can deliver good performance for many years if you use it and treat it with care. But your drill battery is likely to die out much before that, making your cordless drill virtually useless. But if you know the correct battery reconditioning methods, you can make the battery work like new for a really long time.
Eventually all drill batteries lose their capacity to hold a charge and deliver optimal power. But reconditioning can revive and rejuvenate batteries that you thought were dead. What you have to do depends a lot on the chemistry of the battery.
Newer cordless drills might come with Lithium-ion batteries, but NiMh is still a popular choice because it keeps the over all cost of tool low. Lithium-ion (Li-ion) batteries are more expensive.
Nickel Cadmium (Ni Cad) and NiMh are two common kinds of batteries you will find in cordless drills.
The two main reasons for Ni based drill batteries dying out are:
- Memory effect
- Crystal formation
Reconditioning to Remove Memory Effect
You’ve probably heard term “Memory Effect”. “Memory Effect is the phenomenon that makes a battery lose its capacity to deliver a full charge. It happens more with NiCd batteries much less with NiMh and none whatsoever with Li-ion. In other words only the Nickel based batteries (Ni) suffer from memory effect.”
When a battery is repeatedly partially discharged, it only remembers the last amount of charge it held. If more power is demanded the next time, it shuts down completely as if to protest against the extra work. That in short is the memory effect.
The simplest way to remove a memory effect from a cordless drill is to make it go through a reconditioning charge cycle.
In order to do this:
- Charge the drill fully.
- Discharge it completely under zero load, i.e. allow the drill to run on its own till it stops. People usually accomplish this by taping the trigger in an ON position.
- Charge the battery fully again.
If this procedure improves the performance of the battery then repeat it only after at least one month.
Caution: Do not try this with a battery that’s working properly already. You should charge a normally functioning battery whenever it loses substantial power to function. Do the deep discharge described above only when you are trying to recondition a battery that doesn’t work properly anymore.
Important Note: Check the user manual of the cordless drill. Your charger may be equipped with the ability to deep charge/ recondition the battery. Follow the instructions, if any, before you try this.
If this doesn’t work, it may be time to buy a new battery.
Reconditioning Battery To Remove Crystallisation
NiMh batteries are less prone to the memory effect. In fact many tool manufactures will tell you that their cordless drill is completely free from this effect. This is somewhat true. Memory effect is more common in low drain devices like cordless phones. A cordless drill draws a lot of power, and in bursts.
Modern batteries suffer a lot less from memory effect. Nevertheless batteries in cordless drills still lose their ability to power the tool. It might not be the memory effect but due to the chemical reaction taking place inside the battery every time you charge and discharge it. Newer Nickel based batteries might be less prone to memory effect but they do suffer from “crystalline formation.”
Crystalline formation refers to the condition when crystals form on the anode and cathode inside the battery, reducing the surface that comes in contact with the electrolyte. This can severely reduce the current flowing between the terminals of the battery and hence its effective power.
Crystalline formation occurs over the normal life of the battery but happens a lot faster when the battery is overcharged or charged repeatedly without allowing it to discharge completely.
Severe crystalline formation can result in the larger and sharper edges of the crystals causing permanent damage to the cell inside, facilitating rapid discharges and irreversible malfunction of the battery.
“A battery that hasn’t been reconditioned in over one month may begin to show effects of crystalline formation. After five months there will be a noticeable degradation in battery performance. After six months there might be permanent and irreversible damage inside your cordless drill battery.”
- So its good to recondition your Nickel drill battery once in 30-45 days. Reconditioning requires the battery to be completely discharged to a voltage of 1V per cell. This kind of discharge is the most easily performed by following the deep discharge method described above for removing memory effect.
- Battery reconditioning devices are available in the market for reasonable prices. If you can find one, a reconditioning charger is a good investment if you use cordless drills and other battery powered tools.
- Check your user manual. The charger that came with your drill may already have the reconditioning function in it. Many modern tools come with the guideline that “its okay to leave the battery in the charger when not using it.” This is because the charger takes the battery through the proper reconditioning and maintenance cycle when required.
- If none of these methods are possible perform the “deep discharge” like we mentioned under reconditioning of memory effect. Caution: Do not perform manual deep discharges too often. It also causes stress to a healthy battery.
Reconditioning A Li-ion Drill Battery
New, modern and expensive cordless drills might also come equipped with Lithium-ion batteries. These batteries are different from the aforementioned Nickel based batteries in every possible way. The entire chemistry is different and so is the behaviour. Li-ion batteries have no memory effect and hate deep discharges.
The best way to maintain your Li-ion batteries is to:
- Charge it frequently without letting it drop below 20-30% charge.
- Operate it between 30%-90% charge without either charging or discharging it fully. This will increase the charge cycles of the battery many times.
- Operate and store it in a cool environment as much as possible. Performance and capacity decreases in high temperatures.
- Store the battery in a partially charged state of 40-50%.
- Recondition it by using the drill normally till power drops and give it a full charge.
Li-ion batteries are smart batteries with a smart circuit built into them. Their chargers also usually know how to charge them properly.
Its not that important to charge the battery till only 80-90%. You can charge it fully before use. It is more important to not discharge it completely. There are many ways of reconditioning a dead Li-ion battery.
I will try that method and see iff it WORKS
DON’T DISCHARGE CELLS IN SERIES. The cell with lowest charge WILL REVERSE POLARITY and probably get damaged if not irreversibly destroyed.
I have reconditioned different batteries in my garage to upto 40-60%, this method applies to batteries of its kind but if you are looking to recondition medium and bigger batteries for your cars, UPS and similar.
Very iteresting.
You aren’t being completely honest. While it is true that NiCd batteries do have a memory-effect of not wanting to have the same amount of usable charge if you should get in the habit of re-charging them before they are completely discharged, it doesn’t mean that they remember the previous single charge-discharge cycle as the only factor. It is an accumulation of many such cycles of not completely using the battery pack.
As for Lithium-ion, the only way the technology was usable was through individualized battery charging circuits, as each battery pack required a complex charging curve that is individual to that specific battery, and an incorrect curve generally results in the battery exploding. The occasional explosions one reads about are from those batteries that have a correct curve, so the things are still quite finicky and dangerous.
Just read this article and responses. What you said about Lithium and the complexities, it makes me think that perhaps Samsung need to rethink about their Note 7 and why they cannot get it right. You might have some ideas for them to consider
This is an interesting comment.
Android Os now has manual battery level charing setting.
I have for the longest time wanted a certain feature in my smart phone that allows me to set the battery charge level manually. The android OS now has this feature where you can restrict the phone to get charged to only 80% every single time you plug it in. Once the charging level reaches 80%, the phone stops charging.
However, the iOS still does not have this feature. The iOS has something it calls optimised charging. However, this doesn’t quite work the way I initially thought it did.
How optimised charging on iOS and MacBooks works
The description of optimised charging said that the phone will learn from my usage habits and charge beyond 80% only when it thinks I require it. I took this to mean that if I was not depleting the battery level of my phone every day, then it would understand this and if I plugged it in to charge overnight it would only charge to 80%.
However, this it’s not what optimised charging on iOS devices and MacBooks is. Instead what it does is that it waits to charge the phone completely till the time that it is expecting to get unplugged from the charger. For example, let’s say that you are in the habit of plugging in your phone at around midnight every night and leave it for charging till about 7 am in the morning.
Once the phone has deciphered this pattern it will first charge at a normal rate to 80% and then hold that charge till about five in the morning. It will show you this time on the screen once it has reached 80%. There will be a message that the phone is now under optimised charging and it expects to become completely charged by a certain time.
There are two ways in which this kind of optimised charging helps prolong the battery life of the phone. First of all, it prevent your phone from staying at full charge and plugged in for prolonged period of time, which is something that is apparently not good for the health of lithium ion batteries.
The second way in which optimised charging protects battery is by charging the last 20% of the battery at a much slower rate than the initial 80%.
This is because charging lithium ion batteries beyond 80% causes more stress on the battery chemistry. Also, the heat generated, in this stage of charging is detrimental to the overall battery health of your mobile device.
By charging the battery slowly, it prevents the battery from getting heated during the dust last stages of charging needless to say this method is not as effective as having a manual setting with which you can simply restrict the charging of your mobile device to 80% every single time.
Because optimised charging is something that the iOS learns from user behaviour, any change in this behaviour results in optimised charging getting cancelled till the time that it can learn the pattern all over again for example I bought a new MacBook Air and switched on the optimised battery charging.
Optimised charging only happens after the battery health deteriorates a little
But till now it has not switched on optimised charging because I typically tend to charge it fully and use it for sometime before charging it again. By the way, the battery life on the new MacBook Air is really very good and allows you to use the computer for a full day without any issues.
I have observed that the optimised charging doesn’t happen right from the time you buy a new Apple device and the battery health is a 100%. It only start to happen when the battery health deteriorates somewhat. You can check your battery health status in the iOS device or MacBook settings.
In my case I can use the MacBook Air for a couple of days on a full charge. The point is that if I had a feature in battery settings I could have done more to protect my laptop battery by simply setting the full charge level to 80% since I never need more than 30 – 50% in a days usage.
How do EV chargers handle battery charging levels?
I actually wonder the same thing about the EV vehicles now. If I owned one, I would like to have this particular feature that allows me to charge the battery to a certain level.
I don’t know if there is such a feature and I kind of think that the manufacturers will have built-in enough programming into their chargers to safeguard and prolong the battery life because all EV vehicles seem to come with pretty decent battery guarantee for 7 to 9 years.
The right way to charge an EV?
Every time I think about this, I feel that charging Evs could be a bit of a hassle unless the manufacturers have built in a hands off algorithm into their system. If it is once more up to me to be observant of the battery levels while charging and discharging then the whole process could become a bit of a bother.
It means that I would have to watch when the battery of my EV battery is depleted enough for me to put it on charge but before it hits levels below 20%. Also, I would have to watch out for putting it on charge too soon if it has not depleted enough.
For example, it’s not a good idea for a lithium iron battery to be put on charging when it has only depleted to 90% or 80%.
If charging the EV battery to a full hundred percent is not great for the battery life then I will somehow have to use a timer so I can stop it from doing that. But then again, I will have to anticipate my usage and know for sure that I don’t need the full amount of juice in the EV the next day.
With smaller EV cars that have smaller ranges, I feel this will be less of an issue because every time you use it the car battery will deplete enough for you to put it on charging. And since the range is short you will probably want it charged to 100% every single time.
But with the larger EV cars and vehicles which have a range of few hundred miles this could be an issue. If you use it around sparingly in the city for a day, it might not be a good idea to put them on charge every single night, unless, like I said before, the manufacturer has only has already accounted for this in their charging systems and insured that frequent overnight charging does not hurt the battery life.
I would expect them to have thought of this because battery life expectancy is crucial to EV vehicles success and popularity.
The funny thing about this is that most commercially available EV cars and vehicles have not been around for long enough to put this theory to test or for many real world reviews to come to fore from users.
Tesla is one company that has been around for a very long time, but the other manufacturers have only started mass production the recent few years and the people have also started buying EV vehicles in substantial numbers only recently
Also, for the people that have been using the EV cars, I don’t know if a system exists where they can check the battery health of their car batteries over the years of usage. Maybe only the service centres can check this.
Again, I don’t know precisely what EV battery guarantee covers. For example, it might not cover what is termed as normal deterioration in the battery capacity and life. All Batteries will and do lose their capacity to hold and deliver charge over time.
Maybe the EV vehicle battery guarantee covers this or maybe it does not. For all those of you reading this and planning to buy an EV vehicle, this is something worth looking into and enquiring about, while buying the vehicle.