Is Your Aftermarket Camera Battery Charger Giving You A True 100% Charge?

Watson Duo Charger with example of detachable plate. (click to enlarre)

Last Tuesday a good friend and I planned to meet and explore some rural countryside and small towns of eastern North Carolina.  As part of my normal planning for a photo outing, I always ensure my gear is clean, all cameras are set to my default settings and all batteries are charged.  Then I analyze what gear I will take, depending upon what is planned.  It was during the time when I was charging all of my camera's batteries I noticed something I had never before noticed nor suspected.  

Years ago I bought what many of you might have also purchased, a Watson Duo Battery Charger.  The charger can be purchased with interchangeable plates for many specific camera/battery brands.  Being the plates are interchangeable, for very little cost, additional plates can be purchased to give the battery charger additional versatility.  This charger has performed well and I've never had any issues with it.  I would recommend it to any of you.  I have plates for Nikon, Olympus and Fuji batteries.

However, I noticed a funny thing the other day.  I have three Nikon EN-EL15 batteries for my Nikon Z7 camera.  Wanting to charge all three, I placed one in the included Nikon MH-25a Quick Charger and the other two into the Watson Duo Charger.  The Watson has a digital readout and, I assume, gives an accurate percentage of battery charge when you first insert a battery, then updates the percentage of charge as the battery charges to 100%.  The Nikon has a blinking light that stays illuminated when the battery has reached 100% charge.

I don't remember exactly why, but after the LCD readout showed 100% charge and removing the two batteries from the Watson charger, I placed one of the batteries into the Nikon charger, expecting it to indicate 100% charge as well.  Not so.  The Nikon charger continued to charge the battery for a full 20 minutes more.  I repeated the same test with the other battery as well.  Again, the second battery charged for an additional 20 minutes in the Nikon charger.  After returning from the photo outing, I repeated the same test with the third battery.  Again, 20 minutes of additional charging in the Nikon charger.

Not being an electrical engineer or battery expert and curious to better understand if the Watson was showing 100% but not actually charging to 100%, I tried the same test with three of my Olympus BLH-1 batteries.  To the contrary, after charging to 100% in the Watson Duo Charger, they also immediately showed 100% charge with the Olympus BCH-1 Battery Charger.  

Hmmmm.  Now, I'm wondering what is really going on?

At this point, I just wanted to put this out for everyone's information.  Watson, in my understanding, has always been well thought of as a manufacturer and their battery chargers have been around for a long time and have a great reputation.  I have had my battery charger for a number of years and it has served me well.  I have had no complaints about it.  But there are also a lot of other third party chargers out there being used.  Especially ones that will charge more than one battery at a time, which is really helpful when traveling and needing to charge more than one battery overnight.  Does your aftermarket charger charge to a bonafide 100% charge state?

My thinking about my particular situation is that a) everything is working as it should and I just don't fully understand what I'm seeing, b) the Watson charger, indeed, does charge the Olympus batteries to 100% but not the Nikon batteries, c) both are being charged to 100% but the Nikon electronics are not reading the actual charge level since the charging was done in a charger without Nikon electronics, or d) aftermarket battery chargers work better for some brands than others depending upon the manufacturers' manner in which they design their electronics.  

Most high end cameras today can read out battery charge level and battery life.  Third party chargers may affect those abilities and not register correct charging as would the manufacturer's own charging procedures.  Also, if you use an aftermarket charger and you have noticed that your batteries don't seem to be showing a 100% charge on your camera's LCD for very long (or at all), it might be because that 100% reading is suspect.  They may only be charged to 85 or 90% but read 100%.

This has me thinking about my other small, portable third party chargers that don't have the sophisticated digital readout.  Are they fully charging my batteries or am I just assuming the batteries are fully charged?

My advice is to do your own experiments to see if your aftermarket battery charger is really giving you a 100% charge.  If you do conduct some tests, please comment and let the rest of us know what charger, what brand batteries and what the results of your experiments were.

Join me over at my website, www.dennismook.com. 

Thanks for looking. Enjoy! 

Dennis A. Mook 

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