Top positive review
96 people found this helpful
Nice, but lacking charging instructions
on June 17, 2012
First of all, this product is amazing. A 12V battery pack this lightweight and small with 3.8Amp-hour capacity is something I could only find on Amazon. For the bike headlight project I am using it on, my other options were 12V power tool batteries and chargers, which cost well over $50, and have about the same capacity as this pack. To keep it lightweight, I am staying away from sealed lead-acid and (IMO) obsolete NiCd packs.
I don't usually read instructions, so it did not bother me that the labels on the product and the instruction sheet are all in Chinese. It seemed straight-forward how to plug the charger cord into the pack, so why would I need instructions? The online product description says it takes a 10-hr charge, so I did that before using it. Then I plugged in my light bulb to time how long of a burn time I will get from it. The 10-Watt LED light lasted almost 2 hrs, which was a little less than I was calculating, so I decided to charge it again, and repeat the test. This time, after a 10-hr charge, I only got a few minutes of use. I checked the voltage the battery was putting out, and found only 4.8 V, so I assumed there was an internal short in the pack. Just before I was about to request a return/replacement I decided to investigate the charger again. Long story short, YOU MUST SWITCH THE BATTERY PACK ROCKER SWITCH TO ON (I POSITION) IN ORDER FOR THE CHARGER TO CHARGE THE INTERNAL BATTERIES. It is deceiving that the amber LED glows on the pack with the charger connected and the switch in either position, but be assured you will only be charging when the switch is on. For that, I give this product 4-stars instead of 5.
Other notes: The switch has the common I/O markings, which always confuse me which is on an which means off. I=ON and O=OFF. Also the charger has an indicator LED that changes color depending on the amount it is charging: red when delivering a heavy charge, and green when it is full charged.