It works great for a battery backup charger but sadly that's about ...
927598
This thing is not user friendly ... and keep in mind I am a fairly tech savvy guy. There are too many steps that need to be followed every time you want to connect to this device and I've only successfully gotten it to work maybe twice. It works great for a battery backup charger but sadly that's about all. I find it so cumbersome and frustrating to use that I just don't use it. So I basically have a fancy $50 battery backup thingy ... I do not recommend!
3860479
It's great having a backup but it doesn't support fast charging unfortunately, a feature I use almost every day. If you're diligent about keeping backups charge you'll be ok but I tend forget and end up with all my batteries dead so if you need fast charging like I do invest in one that has it.
899495
Charger works great for top mounted battery terminals or vehicles with easy access, but if the space is tight as on my older Cadillac DeVille which utilizes a battery with side mounts, it was impossible to get a secure contact because of the large size of the contact heads.
1567723
Seems to be a great tender and is nice and compact - just be aware this is not a "charger" but a tender, it is not the right tool for bringing back a severly drained battery, but is intended for keeping a battery at optimal charge over long term storage.
2403812
Drains battery when left connected, must be plugged in all the time or it will slowly zero out the battery.
Huge amounts of RF magnetic radiation, all communication equipment in the area stopped working, including HF, UHF, AM/FM, Weather Radio, WIFI is severely degraded, cell phone is severely degraded.
I wanted this to charge 12v communication batteries in a remote area that does not always have power, but it looks like this will simply not work for anything but automotive batteries.  The wiring is very thin, around 22 AWG, not good for serious charging.  Gets hot.
3198155
the charger works pretty well when charging a battery or the phone, but not both at the same time.

the batteries are very sub par. they only seem to charge to 90% when they indicate full charge, and they die when the phone indicates about 30%. it is nice to have them in a pinch, but they are not as good as they stock battery.
3181304
well, it works IF your battery is not completely dead.  If you do not have at least 2 volts coming out of the battery than you will need to charge it a little with jumper cables to a good battery or on a running car for awhile to get a little juice in the battery.  Was really hoping that I could throw this on the vehicles that had been sitting all winter...but not the case.  Fortunately I had a spare battery and connected that for a while to the existing battery,  Connect negative to negative and positive to positive and just let the juice transfer for a few hours....now you have a slightly charged battery and this charger can do the rest.
2160698
This is a bargain price for two batteries and charger and provides cheap backup power road warriors.  However, the batteries do not support NFC (no Google Wallet transactions or use with NFC tags).  The plug in charger is nice but it charges very slowly.  Not a big deal if you have enough extra batteries.
4626823
I originally got this charger for my Xbox360 and Wii controllers. It worked great for a couple of months of moderate gameplay, but a few batteries began dying after just 10 minutes of use (they usually last about 12 hours of gameplay). I only use duracell batteries specifically designed for this charger.  After a total of about 12 months of ownership, I think only 5 of the 20 batteries I bought can hold a charge longer than 10 minutes. I think the batteries should last a lot longer than a year considering the price. Buyer beware!
2713153
I got this cord as a backup charger for work. It is absolutely horrible as a charger. my phone actually dies while using this as a charger. It works fine for data transfers, so if you are buying this purely to hook up to a computer, then its worth the price. If you are looking for a charger, spend a bit more money and get a better quality cable. This one is amazingly thin, and feels like it is made of cheap materials.
4847397
for the most part this is a great charger for gopro batteries and the wasabi batteries. however, the 5v went out after only a couple uses which was really annoying at times when i was relying on power from cars and solar panels. the euro converter is kind of silly, u would still need to convert the voltage.
2926105
The charger is a nice small size. I like that it has the two USB ports on the front, but for me, I won't have it sitting out unless I need to charge batteries, so they don't do much for me. The reason I gave it a low rating is because every alkaline battery I have tried to charge in it has ended up leaking later inside my devices. I would not recommend this charger if you're relying on it to revive your alkaline batteries. As a standard Ni-Cad charger, it's fine. Then again, there are many other cheaper and simpler chargers that can accomplish the same task of charging Ni-Cad batteries if that's all you're looking for.
2000468
It charges the batteries faster than the standard charger but the ports all have bad connections to the batteries. The 2 front ports work most of the time and the 2 side ports won't connect to the batteries at all
2420956
There are some batteries it works ok for and others not so much... it also is not good for batteries that have been drained very dead that are still good batteries when rejuvenated... often claims there is no battery connected if the voltage is below its preset levels.. makes you start off with a lower setting and it might recognize the battery.. Ive used other chargers that weren't so finicky and charged batteries fine without any dangers... this one also seems a bit aggressive for small batteries like single cell lithium ion... they swell much faster using this unit to charge them. And last,  I have never gotten it to discharge at a rate above 400 mA which is nothing.  Doesn't matter what type of battery or its settings. It will not ever reach the 2A it claims of go above 400mA.
3101805
I used this power supply to charge my Lipo batteries for my RC planes.  This power supply worked fine when I was charging at 3A continuous.  However, the Voltage dropped to an unacceptable level when I tried to charge at 5A.  Even 4A did not work very well.
1010302
It would work great in a pinch if you needed to charge your phone. It doesn't hold a charge for long it only charged my phone to 40% from 15% before it died and had to be charged again.
2320015
Everything that is described about the product is on it. My problem came when I charged my battery pack with my car charger. It suppose to charge at 2A same as my ac power adaptor for my Samsung Galaxy S5. During the charge I started smelling burnt plastic as I was driving in the car. I had to disconnect it because it over heated, so I removed it before a battery exploded or caught fire. Funny thing is that my car charger is not as great at charging as my ac adaptor yet it was able to over heat the battery back after a few minutes. I had two months with it or so, after using it a few times for Pokemon Go. It's dissapointing to buy another one this soon.