Home > Consumer Reviews > Black & Decker CP120B 20-Watt Power Backup Battery Pack

I bought this as a battery backup for my MP3 player. I use it to listen to audio books on airline flights. It does the job fine, but I feel it is overly heavy for the job and has features, like an AC output, which I really don't need. My only real gripe is that it takes a very long time to recharge.

The product works as promised. I was hoping to get 12V DC out the charge port since that's the charge voltage. That port is blocked as an output.

I bought on of these for $5 in the bargain aisle of wal mart, I bought it just for kicks to see if it would charge my Zune, I was happy to see that it did start to charge my zune and was very happy at that point, thinking that I had finally found a USB charger for my wonderful Zune, Turns out there are 2 major problems here, this unit it way to heavy to carry around on only charged my Zune for about 5 - 10 minutes. I figured that I could always take the whole unit apart and wire it up to the 14.7V system of a car, nope, the battery pack inside is only a 9.6V pack, bad things could happen if you hooked it to 14.7v.

For an 1800Mha pack, it should give more than a 10 minute charge.

There are two sizes, the small 800 MAH unit (2 hours) & the large 2000 MAH (5 hours) unit. I purchased the small 10 watt unit & was VERY disappointed so I returned it. It took 17 hour charge for only 2 hours of my XM radio use which was insane. I then purchased the 'heavy' 20 watt unit with much better results. I used it to power my XM radio for 5 hours and it works well to recharge my cell phone twice. It will also power a LED 2 watt (45 watt equiv) light bulb for 7 hours. It also charges in 17 hours but the power available is more satisfactory. I WILL KEEP IT. It will work better if the Lithium Ion version is ever developed.

Ok, I give it 5 stars although out of four I bought, two would not charge properly, but at 3.99 it was worth the extra effort to get them going. Here is the problem with some of these, the batteries have been sitting a while, so after you charge it for a few minutes, some of these may show they are charged, even though they are not. The batteries need to be cycled in these and all of mine have come back to life. Here is what you can do to help bring them back...

1) Charge unit until LED goes green (with a battery that needs to be cycled, it may show its charged after a few minutes. With battery that is in good shape and being dead, it should take around 4 hours to charge)
2) Unplug charger and turn on unit. It may go dead after a few minutes, thats OK. After it shuts itself off, wait 10 minutes.

Repeat the steps above and it should come back to life. The most I repeated the above steps were 4 times before it accepted a full charge, and all mine work now. Hope this helps someone if theirs does not take a proper charge...