terrible the batteries don't hold a charge after a few ...
930387
terrible the batteries don't hold a charge after a few uses,called black and decker,they sent me replacements but they didn't last either,3 batteries in a year and none work
338210
The battery life is AWFUL! They don't even last for a full hour workout after being charged for hours. Do not buy!
2647990
After a few days of use the battery would not hold a charge. The battery charge would go from 100% to <50% as soon as the charger is unplugged. I would not recommend this product.

Update: The initial battery failed after a few days of use and would no longer hold a charge. The seller sent me a replacement battery to replace the defective battery. After about a week of use, the new battery seems to be working fine. I did not give the product 5 stars due to the initial trouble of getting a faulty battery. Great customer service by the seller.
4852946
Got the phone and the battery was instantly terrible. Would not hold a charge for very long, even if I was not using my phone or had apps running. Now it won't charge at all so I can't use the phone.
223542
Batteries worked fine for the first two times I used it. A few months later they could barely run half the time they used to. Don't waste you money and go get the OEM batteries instead. The charger is convenient though.
1825012
Battery does not hold a charge. After just a few months of use. Seller needs to make this right.
788960
horrible product i used a month after i bought them and 3 of 4 batteries were dead.  Cost me 2x as much to fix
1321191
I really enjoyed this product when I got it and even wrote a positive review. But soon after the battery will not hold a charge after just a couple of uses and now this product is completely useless. Don't buy this product.
3415611
Batteries won't hold charge, original batteries provided are garbage, new SONY ones won't hold charge either...
813077
I use a Canon t4i, bought this originally because it's much cheaper than the brand name battery. It worked fine for the first few times, but after 1-2 recharges, one of the batteries died and the other one currently holds only about 30 minutes of charge. I would not buy this again, because it simply isn't reliable.
557786
I've bought 4 sets of these, keep sending them back because even though "new" the batteries will not take a charge. I've tried the batteries in 3 different chargers. Beyond frustrated with BestDealUSA and this product!
3917723
They worked for a few days battery does not last long and now I cannot even get it to turn on
3067994
These batteries are horrible.  I bought three of them to replace the original ones that came with the receivers.  These batteries lasted only a couple of months, before losing their charges.  The original batteries lasted over three years.  These batteries won't hold a charge more than a few hours.  I assume they are Chinese knockoffs.
3488758
Batteries aren't the best quality. Over time they loose their ability to charge and can cause issues with the phone. Specifically issues where the phone doesn't detect the battery, or where the phone registers the batter as no good. These can be a temporary solution to a 3000mAh battery, but I'm overall disappointed in this company for this specific product.
3640484
These batteries are terrible. They never charge to 100% and drain quickly. I bought (2) and one crapped out within a few weeks. The plastic nobs at the bottom also fell off. Stay away from these.
2807161
Like many of the other reviewers found, mine stopped working after a few days of use. I tried changing the batteries, but it just doesn't move anymore. The way this product is built is obviously very poor. Don't waste your time or money.
1874245
Absolutely terrible, died within days of putting in a bunch of new batteries, without even using them that much. Terrible quality, a waste of batteries, would strongly recommend against buying!