6.0Ah OP4050A 40 Volt Lithium-Ion Battery Compatible with Ryobi 40V Battery OP4040 OP40401 OP4030 OP40301 OP4050 OP4015 OP4026 OP40261 OP4026A OP40201 OP40601 OP4060A Cordless Power Tools Battery

Battery works good with tool, haven't had time to test longevity, I just received it in the mail, but I can't give it 5 stars because title, and battery states 4000 mah, but upon receiving I disassembled and it only contains 1500 mah cells

Charged up easily. Appears to work as well as, if not better (larger capacity) than the original. The only spoiler was that the latches are much more difficult to operate when attempting to remove from either the tool or the charger. I look forward to continued use and further evaluation.

Couldn't find a Ryobi factory battery, but this one fit the bill. Fit's perfect and my charger was able to charge it. As for longevity, only time will tell. My factory batteries lasted about 10 years before they died.

For the money these seem to be a great deal. Have only used them for one charge/discharge cycle. I can't tell any difference in operation or life of the charge from the stock battery. Will probably buy again when needed.

These batteries don't last long like at all . I couldn't even finish cutting one board theee times before they died I had to use three batteries to get a small job done .

Bought this a couple of months ago...worked fine with its original charge. After it slowed down, I put it on the charger, and it informed me that it was defective. Tried again....no luck. Noticed that one of the other reviews had the exact same problem...Caveat emptor

It fits my Ryobi 12v drill so let's hope it keeps a charge and lasts.

I purchase a pair of these 30 days ago and one failed (charger showed defective and wouldn't power the too) with 10 days. To get them to fit into the Ryobi charger I had to grind off most of the two locking tabs (and it is still tough to pull them out. The other one is still working but for how long!. I just ordered a different brand.