Why is My Black and Decker Battery Charger Blinking Red? Problem Solved

black and decker battery charger flashing red

You needed to charge a battery for your tools, but when you tried the Black and Decker charger LED started blinking. What does that mean? Is the charger dead or the battery? Most importantly, what can you do about it? Don’t stress over a small light. I’ll explain what the different blinking light patterns indicate. The good news is that your charger is working fine, but you may need a new battery or more patience before you can charge up the tool you need for your project. Before you know it, you’ll be back to work building or repairing things with your Black and Decker tools.

Why is my Black and Decker battery charger blinking red? Your Black and Decker battery charger is blinking red to tell you there’s a problem with the battery. Depending on how the light flashes, it typically indicates a bad battery or that the battery is being charged at a voltage that is too high. Luckily, these both have simple, practical solutions you can do at home. 

Why Black & Decker Battery Chargers Flash

There are two different standard flashing patterns for most Black and Decker battery chargers. Each one indicates a different problem with your battery, but the charger is simply fine. Unfortunately, many people assume that the blinks mean the charger is faulty or burnt out. Don’t waste money throwing out a perfectly good charger.

The good news is that if you get a second charger, you’ll have an emergency backup. That’s a smart plan anyhow. You never know when you’ll need more than one battery to do a job. Still, don’t give up on your blinking B&D just yet.

Make sure you read all the instructions that come with your model. Some have advanced features that may include additional blink patterns. A charger that can tell you precisely what’s wrong is a real boon.

Long & Short Blink Pattern

To determine what’s gone wrong, you need to look at the pattern of blinks on your Black and Decker Battery Charger. If you’re getting a series of alternating long and short flashes while charging your drill battery, then your battery has a temperature problem. The charger won’t run power when it detects too much heat or cold.

Blinking isn’t a problem; it’s a failsafe to protect you and your batteries. The solution is simple. You need to feel the battery and take a little time to let it cool down, or warm-up. Similarly, if you have the charger near a heating vent, or in an unheated garage in winter, which might be the issue.

You can easily move both the charger and the batteries somewhere that’s closer to room temperature. For best results, always charge batteries between 65°F and 75°F (18°- 24°C). Doing this will help prolong the life of your device and power sources.

Make sure you never use a Black and Decker charger or battery pack in temperatures below +40°F (+4.5°C). Likewise, there’s a risk of charging above +105°F (+40.5°C). Killing battery-life or your charger won’t do you any good.

More importantly, you don’t want to risk causing the batteries to break open from a rapid temperature change or too much heat. Battery acid is dangerous to humans, the environment, and anything on which it lands. It’s always best to heed the manufacturers’ warnings.

Fast Flashing

The other blink pattern on a 40v Black and Decker charger is a series of rapid, short blinks. In this case, the light indicates a bad battery. When your power source is damaged, or too weak, it will trip this reaction in your charger. As a result, you should remove it immediately and stop trying to charge it.

Unfortunately, you may need to replace the battery when this happens. However, when you use a Li-ion, there may be another solution. I’ll walk you through the process of reconditioning this style in the next section.

For smaller batteries between ten-point-eight volts and eighteen, I recommend the Flagpower PCC692L  Lithium-ion Battery Charger. The included coming system will help you dissipate heat associated with charging more evenly. Plus, it comes with a thirty-day money-back guarantee and eighteen months of outstanding manufacturers’ support in case you have more questions. To learn more on Amazon, click here. 

Repair Batteries So Your Black & Decker Charger Won’t Blink

When your Black and Decker battery charger blinks to let you know your Li-ion battery is dead, it isn’t always the end of the line. Unlike many older styles, these lithium batteries are recoverable in some cases. However, you have to follow the steps to recondition.

Sometimes this is known as ‘boosting,’ ‘reviving,’ or ‘recovering,’ a battery. Regardless of what you call the process, it’s easy enough for most DIYers to accomplish in a few hours or less. You will need safety glasses, a voltmeter, and a charger.

I recommend using the Black+Decker BDFC240  9.6V to 24V Charger from Amazon to recondition batteries. This O.E.M. approved part is a great replacement or spare charger that fits numerous B&D batteries. You’ll be pleasantly surprised by the versatility. Check the reviews by clicking here. 

Steps To Recondition Lithium-Ion Batteries

Not all batteries are revivable. Only Li-ion cells work this way and may come back to life. However, it’s not a guarantee that any one battery is salvageable. Especially if it has no power at all, then you might not be able to save it. In that case, you’ll have to get a new battery.

Some other batteries can also be reconditioned, but you’ll need a different process. The list below only applies to lithium batteries. You can also try shocking the battery, but I consider that an advanced technique. Try this method first.

Save Your Batteries Step By Step

  1. Be Safe- Please use your safety glasses. Your Li-ion batteries have a flammable electrolyte inside, and you need to wear protection to stay safe.
  2. Check Your Voltage- Use a voltmeter to check the battery for any sign of power. Lithium batteries go into sleep mode when the power gets too low. Hence a battery that’s registering a minimal charge may simply be powered down and not powerless.
  3. Place the battery in a Charger- Some chargers have a battery wake-up feature. These may help you revive a sleeping Li-ion battery. Keep in mind it’s not a guarantee, but it often works.
  4. Wait a Minute- After one to five minutes, you should remove the battery and recheck it. If the charge is going up or staying stable, then you probably have a conditionnable Li-ion in your hands.
  5. Finish Charging- Place the battery in the charger and let it recharge fully. This can take several hours. You need to be patient and allow it to charge completely.
  6. Discharge Again- Use all the power you just gave that battery. Preferably, you should use your Li-ion battery in a device that will power up rapidly.
  7. Ice It- Once the battery is empty again, you need to freeze it. Yes, I mean put the battery inside a plastic bag and put it inside your freezer for twenty-four hours.
  8. Thaw & Charge- Bring your frozen battery to room temperature and then charge it fully again. After this, make sure you store the battery at room temperature or less.

Always keep your Li-ion batteries at the right temperature and check them frequently. You should recharge any cell that’s empty or getting low. Contrary to the popular myth, letting a battery die isn’t the best choice, and it does not harm a lithium battery to be recharged when it has some remaining power—quite the opposite. You shouldn’t let this type of battery go to sleep or run entirely out of power, if possible.

Black & Decker Battery Charger Isn’t Blinking

What happens when your 40v or less Black and Decker battery charger isn’t blinking, and it won’t charge? Is it dead in the water, or can you still save the device?

Well, the answer depends on why it’s not working correctly. Even the best charger can wear out over time. However, some problems aren’t as bad as they look. Significant repairs aren’t something you should attempt at home unless you’re an electrician or qualified professional.

Begin with the obvious. Check the cords’ connections to the wall and charger. Afterward, check to see that the battery is sitting in the charger right with the polarity facing the correct direction. Sometimes there’s no problem at all except minor human error.

Ask yourself if the charger had any accidents. Was it plugged in during a power outage? Surges can damage your charger. Additionally, water, including ambient moisture in the air, can cause your device serious harm.

If you have the voltmeter I recommended for renewing Li-ion batteries, then you can check the charger to see if it’s getting power. When you have a charger that’s getting power, consider that the light may be broken. Then check the battery manually with the meter to see if it’s charging.

Are you looking for a high-quality replacement charger? Try the Black+Decker BDCAC202B 20V MAX. This ultra-fast charger from Amazon will impress you with its forty-five-minute charging time. Better yet, maintenance mode can optimize your charge, so the batteries last longer. Make sure you order from an authorized dealer by clicking here. 

Charger Manuals for Black and Decker

Model (click on the link to go to the manual)
BC15BD 15 Amp Bench Battery Charger
Black and Decker 500
Black and Decker Smart Battery

Final Thoughts

Black and Decker’s 40v and 20v chargers are particular to the companies’ products. You should never use a charger for B&D tools unless it’s specifically compatible. The instruction manual warns of this, so you can read all about it if you need more details. For those without a manual, you can find a copy online.

Fortunately, not only can you recondition lithium batteries, but checking your charger is easy as well. If your B&D charger has other issues, check out this video for troubleshooting tips. You may be able to fix it yourself reasonably quickly.

A little battery trouble doesn’t have to be a big deal. A blinking charger isn’t dead, but it is warning you there’s a problem so you can fix it.

related post: black and decker 20v battery charger instructions

Aron Blake

I am the lead copywriter on Homezesty and the Webmaster. I have a lot of experience in home renovations and the creation of style. I enjoy writing and sharing my tips on how to create the best living environment. My Linkedin Profile, My Twitter Account

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