ENGPOW 3.7v 850mah Lipo Battery with X4 Battery Charger for Holy Stone F181 F181C F181W Potensic F181DH Force1 F111 JJRC H12C H12W JXD 509g RC FPV Quadcopter(4PCS)

Batteries and charger are great. I replaced batteries of my dromeda quad copter. They last in flight longer and are slightly lighter than originals. Charger works great on 1-4 at a time

Batteries 5-star: they work as well or better than Holy Stone batteries at a lower cost Charging Station 2-star: Battery adapter plugs too loose in receptacles. Ports & lights uncorrelated. USB cord too short. Overall, it works, but poor design. UPDATE Apr 15, 2018: The seller (Three Stone) reached out to me in regard to my dissatisfaction with the charger. They offered me a replacement charger along with four more batteries, no return necessary. Very generous, indeed. Once again, the batteries are all great. While the charger could be improved (see above comments), it does work. Based on seller responsiveness and the superb quality of the batteries, I'm increasing my review to four stars. Once again, the batteries by themselves are 5-star.

Upon receiving I charged all 4 batteries. I plugged the charger into a USB port on a power strip and all the charging lights lit up without any batteries connected so I plugged it into a USB adapter plug and the lights worked accordingly. 2 of the 4 batteries after the initial charge (took about 1.5hrs) worked as advertised. Not a noticible increase in flight time (Holy Stone 181w drone) from original batteries (750mah). The other two did not take a charge, the low battery lights on the drone began to blink within 5 seconds of turing it on and didn't have enough power to even turn the rotors. After i used the 2 good ones I took all 4 and put them through another charge cyle. This time none of the 4 held a charge and all of them showed low power withing a few seconds of turning on the drone. Basically paid $20 for 20 min of flight time. $1/min a little steep for playing with a toy. It sucks because it's a phenomenal drone but I haven't found batteries that are functional in the least. The original batteries lasted a month before they did the same thing as these. Update: Increased to 4 stars due to their top notch cutomer service. Once I get the replacement batteries I will upgrade to 5 stars if they're functioning. Updated to 5 stars as they sent me new batteries and they work well, can definitely see the difference in performance from the original 500mah batteries Their customer service is excellent and follow up to ensure satisfaction.

Charger has not worked since unpacking, sometimes the red lights come on and sometimes they don't. When you can wiggle the cord and get the lights to come on it still does not charge. I have left them charging for hours and still not charged also the batteries seem to be swelled, whats up with that? Poor quality for sure with the charger. UPDATE: The company reached out to me and they are sending replacement batteries and charger. IT only took hours not days for them to respond and they want to correct the issue. I give customer service 5 STARS for their effort. I will give product an updated review when I try out the new one. UPDATE ON PRODUCT.I used the new charger and batteries the company sent to replace the faulty ones and they charged perfectly. I changed to five star because these new ones worked as they were supposed to . Again the customer service was top notch 5 STARS.

Contrary to the description, this product does not fit the WLtoys V686 Quadcopter. It's too thick to fit in the narrow battery holder. However, since this is the second set of batteries I ordered which did not fit the description, I didn't return them. Instead, I took matters into my own hands. I disassembled the quadcopter and modified the battery compartment so nearly any battery that meets the voltage and amperage specifications will fit. Other than that hassle, the batteries perform OK, but I'm disappointed that they do not operate on a charge as long as I expected.

These fit in my F111 Phoenix, but the problem that I have is that the adapter cables that come with this do not fit very well into the charger ports. They are so loose that I have to adjust each one until the lights come on. The lights themselves are unreliable as I’ve had all four in with only 2 or 3 plugged in. Update: So I took my drone out flying and it did well with the original batteries. I put these guys in and performed 1 flip (tested it with another battery also to ensure I wasn’t crazy) and the beacon lights started blinking, indicating low battery. Performance dropped, although the drone flew for another few minutes. Since these are lithium batteries, they cannot be returned. Don’t waste your money with this brand if you own a F111 Phoenix.

Works great! Will charge all 4 batteries in less that an hour. Great fit for the Holy Stone F191W. You will get 8 to 10 minutes flying time.

Liked the price still testing life span of batteries.