UPDATE: I had an issue with the battery about 7 months after I bought it. I spent a month going back and fourth with the seller through emails. Instead of mailing the battery to them the seller instructed me to open the battery and take photos of the battery management system. The seller finally honored the one year warranty and sent me a replacement at no cost. The problem is its not the same battery and I can't really use it. The replacement is significantly larger (approx an inch larger in every dimension) and several pounds heavier. The original battery was narrow enough that I could mount it in the triangle of the frame and the pedals would clear the battery. The new one is so wide that the pedals interfere with the battery. The replacement is essentially useless since I can't mount it where it will work. I appreciate the free battery but it's clearly not the same and it won't work is also labeled 48V instead of 52V. When I notified the seller I was told that the battery was the same but was "mislabeled" as 48V. It makes you wonder if all the battery voltages are all the same from the factory and they just charge more for the 52v. I liked the original battery but if it fails and they have a one year warranty I feel like you should get an exact replacement or your money back. Buy at your own risk because if something happens to it good luck getting a new one to match the original.I bought this battery for my 2006 GT I-drive four full-suspension mountain bike with a large frame size. I have a Bafang BBSHD motor with a 52V controller installed and wanted more range. Overall this is a great battery that gives me tons of range, but see the detailed review below for some things to consider before you buy.First things first, the battery came quickly, as described and was adequately packaged, so no issues there.Original review:The battery is big and heavy. Even though I knew the specs before I ordered, it was still shockingly big when it arrived, so be prepared. The battery comes with bare wire connections. Be prepared to solder the four main wires so you can connect it. There were no directions, but the smaller wire pair marked C+ and C- are for the input (charger) wires, and the larger wire pair are to be attached to the output (motor). Pretty simple if you know how to solder, but something to consider. I also did have to buy a female XT60 connector from a local hobby shop to match my motor connector so I could still switch between this battery and my other smaller battery, but you may be able to use the large SB50 Anderson Power Pole connector that came with it depending on your setup.The next issue was the mounting. With my full suspension bike, the rear shock prevented a clean install in the triangular space of the frame. I bought a seat-post mounted Topeak MTX V-type beam rack to mount the battery to. Even though the rack is rated for 20 lbs, the 16 lb battery is too heavy. On my second ride I hopped a curb and as I came down the mounting clamp hinge failed. If you don't have a full suspension bike, you can buy a rear rack that mounts to the seat post and the frame, and is rated for much higher weight. If you have a full suspension bike though, be prepared to get creative. Until I can figure out a better mounting option over the winter months, I ended up buying a "simple strap" and mounting it to the crossbar with the 6.5 inch dimension parallel to the ground. It's a bit wide and not ideal, but my legs don't hit it and it holds, so it works for me.If you mount it up high on the bike, be prepared to deal with a significant handling difference due to the weight. The handling will suffer, especially if you get off the seat to power up a hill. You will also want to make sure your brakes are up to the task. I have mechanical disks, but I find I have to adjust them often to maintain optimal brake pressure. I don't find the handling to be a deal breaker though. I just have to keep it in mind when going around corners or on a single-track path.The bottom line is that you should mount the battery as low on the bike as you can manage. Below the down tube would be ideal if you can make it work, as the handling will improve with the lower center-of-gravity.Now for the power/range. Let me start by giving you my stats. I'm a big guy. I weigh 300 lbs and I ride with my Camelback backpack that probably weighs in at another 10-15 lbs fully loaded. Add the battery and motor and the bike itself is probably at least 65 lbs. I also ride with knobby tires which increase rolling resistance. When I ride I almost always pedal (I rarely coast on throttle alone), and with this bike with no motor or battery I average around 14-15 mph. I give you this info so you can determine for yourself what type of power/range you are looking for.The battery provides a bit more voltage at every setting than the battery that I received with the motor. I can get a solid 1500 W of power at the maximum level, which is plenty for me.My first long ride was 42 miles, with 1,300 feet of elevation change on a paved bike path. During the ride I would say I kept the power delivery between 400W to 700W 90% of the time. When I got back I still had 40% battery left at the end. I expect the range will decrease over time like all lithium batteries, but the range is excellent, and I suspect the range for this type of riding could have flirted 60 miles. You might get more if you're a normally-sized adult, have a road bike or have slick tires.Overall this battery gave me the range I was looking for. Just be sure you think about how you will mount it, especially if you have a full-suspension bike. And be prepared for the change in handling characteristics. If you don't plan on going on 50-60+ mile rides, you might consider a smaller battery that is lighter and easier to mount. If range is what you need, this is a great option if you can make it work on your bike. The seller was also quick to answer my questions.The reason I gave four stars instead of five is due to the bulky shape. It would be better if it were a shape that was easier to mount low on the down tube. And even though it's not complicated, some instructions would have been nice as well.This is being used as a second battery for my blix Packa e bike. Using only this battery I've twice ridden 60+mile rides on a single charge! Even as the voltage drops it still outputs enough to keep me moving at 18mph on hills except the steepest of them.As for the battery management system using a grin brand charger it balances cells when charging to 80% which gives you much longer battery life and longer ride times because you have no weak cellsIn the attached photo the large box behind seat post is almost entirely battery, the smaller box on top holds fuses and key switch.I liked my bike before, this battery has brought that up to loving the bike.Update;Reaching end of season I've ridden about 3000 miles using this battery and I've got nothing but good to say about it. Longest ride is 101 miles all at highest pedal assist finished with 40% battery capacity remaining (measured with multi meter thru the charge port), using the 35 amp hr 48v battery with 12.8 amp hr factory battery using a battery balancer. For every volt I drop I average 10+miles even when climbing hills. My normal charge is 85% (to 52.6v) using grin charger. It's nice not to have any range anxiety, I've got over 20 rides over 80 miles and always have had plenty of reserve, 38% is the lowest that I've ever end a ride with.Ive put this battery through a beating on escooter crashed 4 times heavy use and battery is still good no problems the charger internal fan did stop working and had to order a new cooling fan about $10 shipped seems like it takes 20 perenct longer to charge now but i keep the charger on the bike so it was also put through alot of heavy use and impacts so i dont hold it against quality of productGreat serviceBuyer is very responsive and product worked greatGreat communication with seller. I’m very happy with my purchase. Have a problem with battery.Seller resolve problem quickly and send replacement. Fast and very helpful. Recommend this seller.First, let me get the negative out of the way. The item arrived without the discharge and charger port connected, which was disappointing for someone like me who isn't mechanically inclined. However, I was easily able to connect the supplied charger port. It would be nice if they gave you the option to tell them what ports you wanted for your discharge port (they supplied the 50a power-pole but my bike takes the 30 amp). If they give you that option customize connections, I missed it.I have three ebikes and typically purchase my batteries from Luna Cycle and always had a fear of being ripped off from other vendors who sell batteries, but got sick of Luna Cycle always being out of stock. I am so glad they were out of stock because I found a new favorite battery vendor. I ordered the 48v battery but they sent me the 52v battery., 30ah and it was fully charged. It was marked 48v, but I confirmed by testing the battery and charger they are infact 52v (safely charges to 58v before cut off - making it 52v). It was so big it barely fit in my Topeak bag. I am a big Clydesdale rider and me and my bike (Day 6 Samson) likely weigh close to 400lbs, and further, I live in Greater Seattle with lots of hills and as a result, I am very hard on my batteries. The battery shipped from California and reached my house in only a few days after ordering it. This thing is a beast, and way better then any battery I've ever owned, even though this was easily the cheapest battery I've purchased (I paid 489 w/o tax). I've abused this battery looking for a reason to test it out by riding my bike in high peddle assist, using the throttle for long stretches at nearly 30 mph, tackled steep hills, and after 60 miles of riding, I still had 50v (tested with my volt meter). Further, since I was use to using a 48v Luna Whale Shark 17.5 ah, I noticed that not only does this battery have double the range, but my bike feels slightly faster/more responsive (it could be because even though they say the battery is 48v, they actually ship a 52 volt)?