TenergyTN456 Intelligent Universal Battery Charger with 4 Slots, LCD Display, USB Output, Power Adapter, Rechargeable Battery Charger for Li-ion/NiMH/NiCD Rechargeable Batteries

The lowdown — A smart charger that's thought out and built well, recognizes an unusually wide range of batteries, charges them with precision, and even tests them if you want.Rechargeable batteries are more fickle that a lot of us realize, requiring bespoke charging methods and careful cutoff to prevent overcharging and eventual destruction. Tenergy TN456 answers the call. One reason I like it so much is that it recognizes a wider range of batteries than similar devices. For instance, I use "Sub-C" NiMH cells, not common at all, in a wireless soldering iron. Only the TN456 recognizes and charges these correctly.And it covers three battery chemistries instead of the usual two. NiCd and NiMH are par for the course, but the TN456 accepts Li-Ion as well, a chemistry with different voltage and charging protocol.It is well made and exudes a feeling of quality. The backlit LCD screen, highly legible, cycles through various data items as you press the Display button. This smart approach allows the numbers to have a much larger font. The four charging bays, each with their own display, take sizes from AAA all the way up to C, although in case of larger diameters only in a mix as the picture shows. This is a small trade-off against its compact size. It handles from 35 to 70mm in length.(If your battery is shorter than 35mm, say 2/3 or 1/2 AAA, then stack a few dimes in between to create spring tension and contact.)The TN456 also features a 5V USB 2.0 output, a rare yet handy extra.It has two charging modes: "Charge" and "Test." Both modes will lead to a charged battery but Test will also tell you its capacity. To achieve this it tops off the battery first, then discharges it completely to obtain its capacity in mAh, and finally charges it once more. These extra steps take a lot longer than charging alone but are the only way to get an accurate number. If it is near rated capacity then your battery is in good shape.Note that simple charging will also produce a mAh figure. But this one overstates capacity because charging consumes more energy than what gets stored. Note as well that ultimate battery capacity is not set in stone. Repeating discharge/charge cycles will increase the amount of stored mAh. Call it exercise for batteries.You can select the charging current in mA for each bay. The back panel suggests optimal current versus battery capacity. That's a very nice touch since it answers the question asked most often. It also shows how the manufacturer cares about optimal use of its device. The TN456 reverts to its lowest charging current of 300mA if you choose not to adjust. Since all bays are independent, it is not necessary to insert batteries at the same time or even on the same charging mode.If your particular battery is not listed then a reasonable rule of thumb is to charge at a current around 0.5C, where C is the stated capacity in mAh. So if the battery is rated at 1,000mAh then charge at 500mA. A bit lower, say, 0.3C will increase total charge but takes longer. A much lower current makes it more difficult for the charger to sense proper cutoff, inviting the risk of overcharging. Anything much higher can heat up the battery too much, shortening its life. As failsafe the TN456 monitors temperature in the battery bay and shuts itself down if things get too hot.Finally, for enthusiasts, this charger indicates internal resistance in milli-ohms (mR), another uncommon feature. The lower the better. Anything below 100mR suggests a healthy battery. Knowing internal resistance and measured capacity helps you assemble matched battery sets. Since this resistance goes down with charging it is best to obtain it after starting an extra cycle. The batteries are already charged so the charger will stop quickly by itself. No worries there.NiCd versus NiMH — NiMH cells are almost always the preferred choice because, being a modern development, they simply work better. For instance, their energy density is much higher than that of NiCd. This means they pack more mAh in the same space hence last longer before needing a recharge. And NiMH batteries suffer fewer so-called memory effects that irreversibly reduce capacity over time. They are also less polluting since they do not contain heavy metals.Where NiCd cells still have advantage is in applications requiring very high discharge rates. This is almost never the case in consumer electronics. The device would have to mention it. Also, they keep on working at Arctic temperatures.Li-Ion cells put out a different voltage of 3.7V. Hence they are in no way compatible with NiCd or NiMH applications. While they have the highest energy density of the three chemistries, they also demand the most careful use. Running them to empty will cause damage. Overcharging can lead to conflagrations. That's why it is best by far to select Li-ions with built-in undervolt/overcharge/overheating protection.Summing up — there are several offerings in this premium category. They tend to share features such as the test option I highlighted. What sets the TN456 apart is widest range of recognized batteries, three chemistries instead of two, protection against overheating, a USB port, build quality, compact size, more actionable data, its superb backlit LCD, and a lower price than other top dog chargers.

•• Quick Summation ••The TN456 intelligent charger is excellent. It features an easy to read LCD display, multiple charging currents, and 4 slot capacity. I charge my AA's, AAA's, and 18650's without issue. You can charge 1 by itself or up to 4 completely different types of batteries at once. It also has a USB slot to charge phones. As far as I know, this isn't standard on most other battery chargers (such as the Nitecore D4). Lastly, it has a test function, where you can determine the true mAH rating of your batteries.•• A little backstory + Differences Between Tenergy and Nitecore ••Recently, I began using medical marijuana to treat a couple of issues, ranging from herniated disc pain to lingering concussion symptoms. I know, I know. That's how most battery charger reviews go, right? The point is, I acquired a vaporizer that requires 18650 lithium-ion batteries. Until a few months ago, I didn't know these monstrosities even existed. Unfortunately, the single battery charger my unit came with has a high failure rate. It also charges one at a time, so I wanted an upgrade (as I'd bought several spare batteries). According to my initial research, everything pointed towards the Nitecore D4. At the time of my research, the Nitecore D4 was $60. It has since dropped to $40, making it a great value. Well, the Tenergy is brand new to the Amazon Canada Marketplace. Are the differences worth $60? That'll be a matter of opinion.Here are the major differences between the Nitecore D4 and the Tenergy TN456 as I see them:1) Display Parameters - The Nitecore has a basic display, but it shows charge in mAH, voltage, and time spent charging. Similarly, on the Tenergy, you can cycle through the same parameters; however, they're displayed boldly and individually. Regarding the backlight, each company adopted the opposite methodology. Tenergy's screen is unlit unless you press the mode swap, which sparks the backlight, clearly illuminating the display even in the dark. On the Nitecore, the backlight is on by DEFAULT. You have to manually change it into night mode to turn the back-lighting off. Ultimately, I think the Tenergy's display is slightly nicer, particularly because of the individual battery info... but it's very close. WINNER: Very slight edge to Tenergy based on personal preference.2) Current Range - The Nitecore advertises charging at 750mAH. This is true IF you are charging 1-2 batteries. However, if you charge 3-4, the current drops to 350mAH as a standard. Many Amazon reviewers have corroborated this, so it's not an occasional phenomenon. The Tenergy, on the other hand, can charge at several levels between 300mAH and 1000mAH (whichever you require), and when you charge 3-4, it will NOT drop the charging current. WINNER: Tenergy3) Test Mode - The Tenergy has the ability to test your battery capacity, fully charging it, draining it, and then charging it to measured, test capacity. The Nitecore D4 does not have this capability. WINNER: Tenergy4) Production Location - I could not find out where Nitecore chargers were manufactured. Their main website is aloof as to their production location. All I know is that their flashlights company is based out of Singapore, so... I still don't know where their chargers are manufactured. Tenergy is based out of Silicon Valley, California. They built a production plant there in 2009. So if you're looking to keep things local, Tenergy is a good bet. WINNER: Tenergy5) Price - The Nitecore D4 started at $60. In 2015, it acquired an update, and more recently, it dropped to $40. This makes it a very strong candidate for a budget, no frills charger. The Tenergy is brand new on the Amazon Marketplace. At $60, you're paying for the difference in charging and North American make. WINNER: Depends on what you're looking for~ Other Stuff ~Each individual battery display flashes "FULL" when it's finished charging. That's aboot it.•• Conclusion ••The Tenergy TN456 is a great charger. If you want a unit that can test battery capacity and has a guaranteed 1000mAH charge capability, go with the Tenergy. Keep in mind, the additional phone charge slot. I suspect the price will lower the longer it's on the marketplace, too. One last point is that the instructions are written in very clear English. This isn't a Chinese re-brand with unintelligible instructions. If you're simply looking for a cheaper, effective charger, cast your gaze to the Nitecore series. The i4 is even cheaper than the D4; it simply lacks the LCD display.Edited note: This charger does not come standard with a car adapter.

Smart, adjustable, includes lots of useful info, and can charge quite a few battery types.

This charger works as intended. They screen is easy to read and has backlighting. The user interface is also easy to use, and offers 300,500,700 and 1000mA charging, and also offers a charge\discharge feature (The discharge is at a constant 500mA). The info is accurate and easy to find thru the user interface.The only cons this thing has is that it uses a wall wart instead of an internal power supply and that it can only deliver max 1A (1000mA) charging per slot.Attached is a couple pictures of the charger on Test/Charge mode. The info shown is the actual capacity of the batteries.

I like Tenergy products. This is similar to a La Crosse charger I bought years ago and still use. This one is well made and can take up to 2 C cells with 2 AA or AAA cells.Read the small print. It can’t take 4 C cells at once, it’s too small.You can set individual charging rates for each cell along with individual test and discharge functions.