Do’s and Don’t’s of Cordless Battery Charging

by Jeff Andrews, Northern Tails Sharpening

When buying new cordless clippers most groomers forget to read the fine print in the instruction manual, and some forget to read it altogether. Your manual may say it is acceptable to leave the cordless clippers in their charging stand all the time, or batteries won’t obtain a memory or become overcharged. Don’t believe it! Based on my experience it may be convenient to do so, but if you want more assurance you will avoid burned up handsets and dead batteries, don’t. I exercise caution over convenience. No matter what the manufacturer states, or the type of battery, there is a chance you may “overcook” it with extended charging.

I learned from experience how to extend battery life and running time with a simple protocol. It involves a little more work on your part, but isn’t it worth it to have your clippers running when you need them? Follow this easy protocol with cordless trimmers as well as A5 cordless clippers.


When you get new cordless clippers chances are the batteries will have a charge in them. How much is unknown. The initial charging of batteries can affect their useful life.

I ran the charge out of a new battery by running the clipper until it was completely dead. You won’t hurt clippers by running them without a blade on them. Mine ran about 10 minutes before the motor slowly came to a stop. If you have external batteries you can do this for each battery. Don’t rely on a button on your charging stand for depleting the charge. Most likely it won’t drain in the same way as running the clipper. Once depleted put the battery or clipper in the charging stand (or hook up the power cord) and start initial charging.

Be sure to only charge the battery until the indicator says its fully-charged. Then, stop charging the battery. Even though the manual says the charger will automatically stop charging when its fully charged, don’t rely on it. Take the battery completely out of the charger. Only then do you really know charging has stopped. If charging were to continue it could potentially overcook the battery causing cell damage resulting in its not holding a charge very long. With your batteries charged and removed from charging you are ready to start grooming.


Use your clipper normally. Assume you have been running it for a while and are done with a groom. What do you next? You probably want to put it back on the charger like the manual says you can do. Should you? I have learned not to. Replacing the handset or battery back in the charger after short runs when the battery has not depleted its charge can cause “battery memory.”

The battery was designed to let you use the clipper run for a long time. Replacing it on the charger after short runs seems to teach the battery it only needs to run for short periods. I assume battery cells can adjust themselves to run for short periods because it has been my experience. As a result many groomers think their batteries aren’t holding charges very long or that their clippers are bad. In my experience once they get “memory trained” for short runs there is no going back to training them to hold charges for longer periods of use.


Here is my protocol for a cordless trimmer. It has an internal battery and a charging stand with an attached power cord allowing it to run household current. In the five years I’ve used it before writing this article, I’ve have had no problems with battery life, charging or hot handset problems. I prepared it for initial charging by running it until the battery was dead. Next I charged it and stopped the charging process entirely once it reached full-charge.

I used the trimmer for several grooms never putting it back in the charger between uses. I used it until there was no charge left in the battery. I was pleasantly surprised how long it ran. It makes grooming more enjoyable. That is why I am so motivated to maintain the long groom time with my protocol. If the charge becomes depleted during a groom I hook up the power cord and finish the groom. If you are using external batteries, change the battery and finish the job, then charge the dead battery. Keep the fresh battery in the clipper and use it until the charge is completely gone before changing batteries.

Remember, don’t leave the power cord hooked up after it is completely recharged. Instead, disconnect it. Never leave the trimmer or clipper in the charging base when not using it. Recharge batteries only when there is no charge left, and only recharge long enough to get a full-charge. Following this protocol you may find a solution for your battery problems. I know I did and hope it works for you too. ♦