Bests & Worsts Reviews from Amazon

In short, this device IS able to charge most of my used Alkaline batteries that were sitting in a bucket, waiting to be thrown away. This charger is NOT a well-made product. It looks cheaply made and does not appear convincingly sophisticated enough for me to even want to try testing its claim of the capability to charge disposable Alkaline batteries. But there were enough positive reviews on Amazon that pushed me to give it a try, so I ordered one. My unit arrived a few days later, but I found the transparent plastic lid broken at one of its hinges. I emailed the seller about the condition and was promised that the issue will be resolved. The charger has bays to take AA, AAA, C, or D size batteries four at a time. A LCD panel displays the charging progress of each battery individually. There is a corresponding LED located in the front of each charging bay to indicate the state of the battery. There is also a fifth place to accomodate a 9-Volt battery. There is a 3-position switch (Ni-Cd, Ni-MH, and Alkaline) that you must set to indicate the chemistry of the batteries that you want to charge. You cannot mix batteries of different chemistry in the same charge session. I first sorted out my bucket of used Alkaline batteries, throwing out ones that showed signs of corrosion or otherwise didn't physically look clean. As soon as I put in a battery, it's corresponding LED will indicate whether the battery can be charged or not. A steady red means it can be charged, and a flashing red means the battery is bad. When charging is complete, the steady red will turn to green. I found that, after an LED has turned green, it is a good idea to roll or jostle the battery in its bay slightly but not so much as to dislodge it from the + and - contact plates, or take it out then immediately put it back in, to see if the LED still displays green. If so, that means it is indeed charged as much as possible. Otherwise, just let it charge until the above test always yields a green color LED indication. Similarly, when you first put in a battery to charge, if you get an flasing red LED telling you that battery is bad, try putting it in a different bay to see if you get the same indication. I was able to charge over 90% of the batteries that were going to be thrown out. Some probably couldn't be charged because they were overly depleted. Ni-MH batteries will become warm when charged, but Alkaline batteries curiously stayed cool throughout the entire process, as if no charging were done. I had to use a voltmeter to ascertain that they were indeed renewed. According to the the manufacturer - ViaTek, batteries can be charged up to 70 times. The battery makers certainly don't like this device, just as gasoline producers don't like electric cars. But this can save you a lot of money and at the same time save our environment. I highly recommend this product and will update my review after I thoroughly used the re-charged batteries in my electronic gadgets to report on their stamina and other characteristics. Update: After re-charging the Alkaline batteries, it is a good idea to lay them flat on a piece of paper and let them sit there for a few days, to see if there is any fluid leakage. Out of the thirty or so batteries that I was able to re-charge, I later found two were leaking fluid, so it's better that you make sure that non leaked before they are used in any equipment. Throw away the leaking batteries. Update (January 4, 2011): Generally, this unit is fantastic, but be sure to check the physical condition of your used batteries BOTH BEFORE AND AFTER you charge them. You should also check if the charger's battery bays have any leaking fluid left there by bad batteries. This rarely happens, especially if you are stringent about quality, but you must clean it up before the fluid corrodes the metal contacts. I use cotton swab dipped in baking soda dissolved in water to do the job. Use tissue paper to wipe dry all surfaces. To get the best results, adhere to the three rules: 1. Never use your batteries until they are dead; it's like stretching a rubber band so much that when released, it won't return to its original shape. 70%-80% used is better. 2. Fresh batteries perform much better than old and expired batteries. 3. Always inspect the batteries carefully before putting them in electronics products. Batteries WILL CORRODE OVER TIME, even the best ones! So if you don't plan to use a piece of electronics for more than a month, it is a good idea to take out the batteries. If you forget, it may cost you that piece of electronics! Update (January 10, 2011): Periodically check the state of batteries installed inside your electronic gadgets. If a gadget is pretty expensive, it's probably best not to use these recharged Alkalines. Update (February 14, 2011) I recently discovered that, after charging, a higher percentage of certain brands of Alkaline batteries will LEAK fluids more than others. The trouble is, they don't leak right away. Therefore, after charging, you should always leave them on top of tissue paper for a week or two to see what happens. This precaution will prevent damage to electronic equipment as a result of fluid leakage. Update (July 4, 2012) Because "real" rechargeable batteries almost never corrode over time, I use them in expensive and occasionally-used gadgets, so in case I forget to take out the batteries, they won't damage the equipment. I use recharged alkaline batteries in stuffs that don't cost a lot and are often used (so that I will discover the batteries getting bad ASAP), such as a wireless mouse, TV remote, portable voice recorder, etc. Update (October 31, 2013) I am still happily using this charger to renew used alkaline batteries. I found that keeping batteries in the refrigerator is a good way to slow down the battery degrading-over-time process. They should be stored in double-bagged Ziploc bags and not taken out the bag for use until at least one hour after being taken out of the fridge. This is to avoid condensation forming around the batteries. A cold battery will not perform well; it needs to return to normal room temperature first. Update (December 26, 2013) A completely discharged alkaline battery cannot be recharged. I'd suggest using new alkaline battery up to 1/3 juice left, then recharge it for good result. The recharged alkaline battery performs fine and retains electrical charge well. You will need to experiment with different makes to find the best performer, although keep in mind that battery makers constantly try to make their alkaline batteries as not-rechargeable as possible. ;) If you get some corrosion fluid on the metal contacts of the charger, use cotton swab dabbed in dissolved baking soda water to clean, then dry them with tissue or dry and clean cotton swabs.