AA/AAA Battery Charger USB and Mobile Device Charger

It works on Samsung Galaxy 4. If you use cheap batteries. You get cheap results... get good batteries . It works good.

Can't beat it, for the price. Make sure you select the attatchment or they will just give you one- I got an iPhone 4 attatchment. Get quality battery's; it's Amazon, they sell some of the best for a good price. 4 of their AA's, out of the box, charged my iPhone instantly. I believe, if your phone charger has a USB end, it can be directly plugged into this device (no attatchment needed). I'll probably be getting another for a car or two.

I'm looking for a battery charger that can work both directions: either to recharge four AA/AAA batteries from a USB port, or use the four batteries to power the USB port and recharge other devices. Previously I have tested the  PortaPow 4x AA/AAA USB Battery Charger and Power Bank  and found it to be disappointing. That's why I want to try this product ( Battery Charger USB & AC For AA & AAA & Power Bank / External Power Back Up ).The box I received says "FUJICELL SCH500F" outside. Inside, I found a charger that looks EXACTLY like the PortaPow charger except for the color. This is a BAD sign. Just to confirm the two units are not the same internally, I opened up their cases to examine their printed circuit boards. Sure enough, they have the same piece of junk inside.[Battery Charger]The Fujicell charger suffers from the same limitation as most low-cost chargers: it can only charge in pairs. That means you are out of luck if you have appliances that require odd number of batteries. But at least it is semi-smart, in that it will stop charging automatically (LED turns from Red to Green) after the batteries are fully charged.Input of the Fujicell unit is rated '5V 800mA'. In my testing, the measured input current is actually around 890mA (as reported by my  PortaPow USB Power Monitor ). That means the charging current is approximately 445mA for each battery pair. It takes about 5 hours to fully recharge a set of 2000mAh batteries such as  Panasonic eneloop Near the end of charging, I noticed that both the batteries and the base of the charger became very hot. This is because the charger contains a simple linear regulator, which generates a lot of heat due to its poor efficiency.[Power Bank]The Amazon product page says: "Portable Power Bank Storing Up to 11,200 mah". This probable came from the fact that you can put four 2800mAh AA cells in it, so 2800*4=11200mAh. But this number is completely misleading, because the four cells are connected in series, so the overall current capacity is still 2800mAh.The real problem is that there is no voltage regulation at all. The USB output port is driven directly from 4 batteries, minus a diode drop. When the batteries were freshly charged, each cell is around 1.35V. So the output is close to 5V (1.35 * 4 - 0.6 = 4.8V). But as the voltage of each cell drops to 1.25V, the output drops to just 4.5V, which is borderline too low for most USB devices. Another problem is that, since there is no low-power cut-off, the four batteries will continue to power the USB device even though the output voltage is already too low.On the other hand, when I inserted four new alkaline batteries (1.6V each) into this unit, the no-load output voltage actually reached 5.8V. This higher voltage could be dangerous for low power USB devices.[Bottom Line]If all you need is an USB-powered battery charger, then this Fujicell unit is still worth considering. But as a battery-powered USB power bank, I found it to be completely unacceptable. Overall, this is just slightly better value than the PortaPow version, because it comes with an AC power supply plus a USB charging cable/adapter.As the old saying goes: "Fool me once, shame on YOU. Fool me twice, shame on AMAZON" for offering the same product on two separate pages.

I live off the grid and this keeps my eneloops charged very well while on solar.

This is a really good product. It works great.As for the price is not expensive if we compare with its benefit.