Watson Duo LCD Charger with 2 EN-EL15 Battery Plates

My Need:I have a D810 as my main camera and a D300 as my backup and was looking for an adaptable charger to handle them both since I want fresh batteries before a shoot. Alas, the D300 and D810/D800 have different batteries. I could have used the OEM charge blocks to charge 1 of each type separately but would never be able to charge two of the same type at the same time without buying two more charging blocks, one for each type.This Solution:This unit satisfies all my charging needs. It has 2 bays to charge 2 batteries where each battery can be of different types though the use of adapter plates which accomplish 2 things: They fit the battery shape and contacts but also signal the charger what voltages to charge them with. In my case, the D300 and D800/810 batteries have different characteristics. This unit handles both in stride.Adapter Plates:It accomplishes this feat by the use of adapter plates that fit into each charging bay; you then plug your batter into the adapter plate. I bought the main unit that comes with two EN-EL15 batteries adapters for my D800/D810 batteries.Since my backup camera is the Nikon D300 and uses the EN-EL3 battery, I also bought 2 of the “Watson Battery Adapter Plate for EN-EL3 / EN-EL3e & NP-150” to charge up to two EN-EL3 D300 batteries. To charge your batteries you snap in the adapter plates for the given battery type then slide in the battery into the plate.Sample Usage Scenario:The greatest benefit for me has to do with my session preparation flow. When I go on a shoot, the most important thing is to have at least one battery each of my D810 and D300 models be fully charged. The next, much lower priority is for each model to have both its batteries fully charged. My logic is based on the following worst case scenario.Assume there is a job we have to get to in a few hours, there may not be time to charge 2 sets of 2 batteries, and all 4 batteries are dead or nearly so. So, we need to figure out which batteries to charge first to give us the maximum power insurance if we do not have enough time to charge all four.The basis of the solution is obvious once you see it (old design joke). Having two fully charged batteries for a broken dead body is useless. Ergo, the best approach is to charge 1 battery of each type. In the case you couldn’t charge a 2nd set and the battery for the main body ran out, I can switch bodies and continue shooting with minor adjustments for lenses and resolution. This unit allows me to accomplish that protocol: Charging one battery of each type at the same time. Whatever time I have left before leaving, I charge the other one of each type. Voila!Track Record:So far, this unit is serving me well. It is great having two charging bays, adapters to charge different battery types, and an advanced informative backlit LCD display that shows voltage and charge state of each battery. Upon first use, it seemed like the display was a bit erratic in its readings but I came to realize it takes a few seconds to test the state of charge of the batteries.As some may know, to test a battery more accurately, you need to apply a known load, measure the voltages and current dissipation, and then compute a state of charge based on the standard specs of the battery. It’s an imperfect science and I cannot attest that this is what the unit is actually doing but works as if it were and produces readings that seem accurate.Aesthetically, the LCD display is far cooler and more gratifying to look at than a featureless solid plastic charger block with a small LED that is either OFF, Flashing, or ON.Ergonomics:The unit works easily and logically but the adapter plates need some care.Minor problem with adapter plates:There is a minor design flaw related to how the adapter plates fit into the charge bays. The force required to snap in the adapters is the same or a bit less than the force needed to insert the batteries into the adapters. As a result, when you slide out a battery, you may inadvertently also slide out the adapter plate. This is a very minor inconvenience. After pulling out a few times, you learn that you can hold down the surrounding plate as you pull out the battery. I never once thought of returning the unit for this minor hassle. The ideal design would have been to have a slide lock or push release button for the adapter plates. That would only add pennies to the design. They should have asked me first :-) I demoted the rating by a ½ star for this minor design flaw.Longer Term:I’ve had the unit in service for about 3 months and, so far, it hasn’t malfunctioned once, the display continues to operate correctly, and the batteries seemed to be charging to their full capacity. In this time, I’ve charged two battery types about 10 times each. I’ll update this review if things change.UPDATE: 2015-05-29 The issue with the adapter plates coming off as you remove the battery is just a wee bit more irksome than I first thought. However, it is still only a very minor issue since it is trivial to pull the adapter off of the battery if it did come off with it and slip it back into the charger body - taking all of 3-5 seconds. Also keep in mind how often you charge your batteries. I am a retired pro, still shoot a great deal, and typically only need to charge my Nikon batteries once a month with light use, once a week with moderate use, once every few days with heavy use, and daily or more for astrophotography, location, or studio sessions. For me, the convenience of charging both my D300 and D810 batteries (or 2 of either) at the same time erases any hassled thoughts about the adapter plate issue. So, I slightly reduced my rating from 4.5 to 4.4 stars.

The first one I received was faulty, but Amazon took it back and reimbursed me without question. The new one is perfect. It does exactly what it says it does. Charges two batteries independently at a reasonable charge rate (not a trickle, but not so fast it damages the battery) and displays the status of the charge at the same time. I won't regurgitate their description of the product; suffice it to say I am happy with how well it works. As other reviewers have mentioned, this charger works on many batteries by simply using different inserts, and those inserts do not stay in place when removing the battery. That is the only design flaw I have found, but it's such a simple fix I'm rating it down for the inconvenience to the user.

Im always a bet skeptical when something sounds too good. This product lives performs as advertised. I use it for EN-EL 15 batteries for my Nikon d7200. Charges rapidly and the visual indication appears to be accurate when compared with battery level as lead by the camera. I also purchased the adapter plates to allow charging of EN-EL3 used in older cameras, e.g., D90. Results are also excellent. This product allows for easy, relatively rapid simultaneous charging of two batteries. A big plus. Definitely recommended.

Owned for only 6 months and one side stopped charging, it pretends it does but does not actually charge. I like the lcd display a lot and the one side that charges is quick

Charges batteries fast (when it works) but power level display is not reliable. Battery adapter comes off when battery is pulled out. On top of that I received a defective charger, the right slot was not charging properly

I like the LCD screen and the charging data that it provides. I also like the speed of charge. The fact that the power converter is built into the unit instead of being a chunk on the power cord is also a plus. I would have given this charger five stars instead of four, but I find the batter containers annoying when I am removing a battery from the charger. I have to be careful or the containers will pop out. Once out, the little units are hard to get back into place.

This is my second Watson Duo LCD Charger with EN-EL 15 plates. I bought the first one some four years ago, I think. It too is working well. I very much like that it charges two at a time and uses both household AC and automotive DC. Thank you. I have several other chargers that work well enough, but this one sits supreme.

The very best charger. I shoot weddings and am very hard on batteries. This charger charges the batteries at the optimum speed and matches the capacity of different batteries from different manufacturers keeping them from failing while on the job. A must for me. I also have the Watson AA 8 bay batteries charger. I can’t recommend them enough

I would give this unit five stars except the adaptor inserts tend to slip out. Other that that it is a very useful charger. I have dragged it across three continents in place of my Nikon charger (which was to expensive to replace). It charges both Nikon branded and 3rd party batteries.