52V 20Ah Ebike Battery - Lithium Ion Bike Battery for 0-1500W Electric Bike Kit, for BAFANG Voilamart AW Ebikeling Pexmor L-Fater E-Bike Conversion Kit - W/Charger & BMS

Buying a new battery for your ebike is challenging. There are many choices, and to find the one with the characteristics you want is not made any easier by the marketing material presented. I think if a manufacturer was careful about their sales material and specifically and accurately described their product, they would get an advantage that would show up in increased sales. None of the web pages I looked at achieved this. The closest match I could find for my needs is this particular Varstrom/Yingwu battery. I hope the key information in their description is accurate, it sure looked good! It is interesting that the Amazon page I bought this from had no reviews, but I took a risk and bought the battery anyway. The first photo shows the dimensions of the battery out of the user manual. The dimensions in the Amazon product description appear to be incorrect, they appear to indicate that it is wider than it is tall, which is not the case. The second photo shows the great packaging provided for the battery, it arrived in perfect shape. Photo #3: When I took the battery out of the box, the first thing I did was measure the voltage, which was 53.5 volts, ~68%. This was encouraging, a very good storage voltage, but it was funny that all four power indicator lights on the battery lit up when I pressed the button, indicating that power was at 76-100%. No big deal, though. Then I got curious about the internals and took the cover off (photo #4, it also shows what-all came in the box. I was impressed that they included 4 mounting screws!) The battery appears to be well made and protected from moisture, including the BMS but not the power level indicator board. The battery is fused and that is visible on the left end. I was hoping to be able to identify the cells, which are supposed to be Samsung 5000mAh, but they and the cell supporting structure were not visible through he opaque plastic cover, which I would not disturb. The case is not sealed with a gasket, but has a tongue and groove edge that should make it hard for water to get in unless the battery is submerged. I fully charged the battery, it charged to the appropriate 58.8V level with the battery power switch in the "on" position as per the instructions. The charger has a cooling fan, I was happy to see that. Photo 5 shows the battery on my DIY fat-tire BBSHD mid-drive ebike, it mounted very nicely, in just the position I wanted, and the power connector was a good length. The battery was easy to install and remove from its mounting plate. My inaugural ride was a 12 mile route with some mild midwest hills. I typically pedal most of the time with 250W of assist, except for going up hills where I'll kick up the PAS and/or lower the gear and keep my effort about the same as on the flats. I did not exceed 600W of assist on this ride, with speeds varying between 12 and 30 mph, mostly cruising around 20 mph. The voltage dropped from 58.8 to 57.2 in 12 miles, just 1.6V, which I was happy with. I view 46V as my low voltage cutoff. 58.8-46=12.8V. 12.8V/1.6V(drop for 12 miles)=8. So a linear approximation of my range, with my typical pedaling characteristics, would be 8x12 miles or 96 miles. Probably a linear approximation isn't totally valid, but it still gives a ballpark estimate for the range, which looks very good for the first full charge and ride at a temperature of about 38 degrees F on a 76 lb bike (I weigh 160). My previous battery, which was also 52V 20Ah, enabled me to attain 73 miles on one charge in its youth. This one may be even better! So, in conclusion, at this point I am happy with my purchase, early indications are that this is a very good battery. I was impressed with all aspects of it at this point, it appears to be of high quality and an excellent value at the current price! I sure would like to actually see the cells that are in there, though. If the marketing people would include a photo of the specific battery internals for each model they offer, before they are wrapped in plastic (or... better yet, use transparent plastic for the waterproofing!), that would be a strong selling point. I will attempt to update this review as time passes and I see how the battery holds up. I'll be interested in the opinion of other purchasers. Update 5/31/2025: I continue to be positively impressed with this battery. The temperature has warmed up enough here in Minnesota to do more of a "room temperature" range test. Riding as described in my previous review, I was able to go 71.7 miles before the voltage got down to my conservative allowed minimum of 46.0 (~23.75%). I live on a fairly steep hill and the voltage actually dropped to 44.3 climbing it but the voltage recovered back to 46.0 when I stopped at the top, completing my range test. The voltage continued to rise while stopped, leveling off at 47.4 volts overnight. If I had climbed this hill at 46.0 V with my previous battery (same voltage and amp hour rating), it would have cut out when it got down around 44 V. The Varstrom/Yingwu did not, it just kept going. That's a lot better than having a surprise power outage while climbing a hill! Its internal controller seems to be a little less cautious at the low end voltages. So... so far so good. This was only my third full recharge cycle. We'll see how it fares after more usage, but it is looking pretty good at this point!

Excellent. Big thanks to the other reviewer who posted a picture of the diagram of the battery so I could scale it to a picture of the frame to see that it would in fact fit the bike ('22 Specialized Rockhopper Sport Medium frame). Wish it was standard practice to post highly accurate drawings for something that needs to fit something else but nevertheless I am both grateful and satisfied.

This is about the fourth battery that I have purchased. It definitely makes a difference when you purchase a battery that uses name brand quality cells.

The battery level indicator that is supposed to light up does not work.

Very happy with my purchase

It could have had a longer power cord but I ended up having an extension for it. I would have gave five stars if they gave a longer cord. It's only 6 in. long.

Great quality, it’s giving me about a 45 mile range on my E bike with a 750 W motor

This battery is excellent. I have a Biktrix Juggernaut and did not want to spend $1,000 for their external extra battery. As long as you make sure you have the correct mount which I had to purchase from Biktrix this battery works great. I can't see where there would be any issues with it working with any other e-bike as well.