Most budget 36V ebike battery packs omit both waterproofing and spend less on the BMS. Not the LGNUO 36V 20Ah. It includes 720 Wh in an enclosed PVC case rated to IP54, and includes a 30 Amp BMS, and is priced per watt-hour lower than nearly all competitors. That is precisely the type of pack a DIYer expects from a budget pack.
There is a single and straightforward warning I want to give you. As of today, there are no customer reviews posted on Amazon for this product, so you are basing your purchase entirely upon the spec sheet. I am not going to tell you that a product with no purchaser history is a proven slam dunk. What I will do is outline for you what each specification of the pack means for your build, what the specifications indicate regarding the performance of the pack, and where you may need to reconsider purchasing the pack.
Specifications and Build Quality
The headline specification for the pack is 720 Wh. This was determined by multiplying the voltage of the pack (36 V) by the amp-hours of the pack (20 Ah). A 36 V 10 AH pack provides 360 WH. Therefore, this pack is equivalent to two 36V 10AH packs in a single enclosure. In terms of commuting, this represents the difference between a short ride and a full day of commuting.
The dimensions of the enclosures are very small at 8.15 x 4.72 x 2.75 inches (207 x 120 x 70 mm) and weigh in at approximately 7 pounds (3 kg). The enclosures will fit on the back of almost every bicycle and will likely fit inside a seatpost-mounted bag or a rear rack bag. At slightly less than 7 pounds, it will not adversely affect the handling characteristics of your bike.
The construction utilizes a waterproof PVC enclosure. Many inexpensive batteries in this same category are shipped in relatively thin plastic cases that will crack at the edges within a year due to vibrations. PVC is thicker and will protect the interior components from dust and water. While it will survive being sprayed with rain, it is best to keep it away from puddles and streams.
You receive an XT60 connection along with a T-plug (Deans) connection on this pack. An XT60 connection is used by virtually all modern ebike controllers. A T-plug connection is commonly found on older controllers and several scooter manufacturers. Both connections provide you with adapters or wiring harnesses that you will not require when connecting to your ebike controller. The pack also contains a 42V 2A charger in addition to the XT60 and T-plug connections.
LGNUO rates the cells contained in their packs as Grade A. Cell grade is the largest determinant of how long a lithium-ion battery will last. Cells graded as "Grade A" maintain their capacity better than other grades of cells and produce less heat during operation under load conditions. The charger provided with this pack is a 42V 2A charger. Charging a 20AH pack such as this using a 2A charger will take approximately ten hours to complete, assuming you start with an empty pack. This assumes you do not partially recharge the pack prior to allowing it to completely drain prior to recharging. Therefore, actual charging times will typically be less than ten hours.
BMS, Safety Features, and Design
The 30A BMS is what separates a good ebike battery from a potentially hazardous one. The BMS manages overcharge events, over-discharge events, short circuits, and excessive currents. Overvoltage management prevents individual cells from exceeding safe operating levels during charging events. Overvoltage can occur if the charging event occurs faster than expected or if the charger cannot manage the rapid increase in voltage associated with charging a large capacity battery quickly. Low voltage management protects individual cells from dropping below recommended operational voltages during discharging events. Discharging individual cells below these minimum recommended levels can cause irreparable damage to individual cells. Short circuit detection disconnects power to the battery immediately upon detecting a short circuit condition. High current detection monitors for excessive current draws to prevent overheating and potential fires. All three of these functions help ensure that lithium batteries remain safe during normal usage.
An important consideration when sizing a BMS is to select a BMS that exceeds the maximum possible continuous current rating of your motor(s). Selecting a BMS that matches your motor's maximum current draw creates excessive heat and reduces the serviceable life of your BMS. This pack's BMS operates safely within its rated limits based on the motor ratings indicated above.
The IP54 rating indicates that this pack is resistant to dust and splashed water coming from any angle. There are many advantages to having an external case that is water-resistant compared to using an unprotected internal frame. Water resistance helps protect the internal electronics from moisture contamination caused by exposure to rain or road spray. However, it is not suitable for immersion in streams or puddles. Consider pointing the connector end downward and keeping it out of direct sunlight or extreme weather conditions.
As mentioned previously, the overall design of this pack is simple and functional. No display screen, no key lock, and no USB charging port were added to reduce costs and create additional failure points.
Range and Compatibility
In terms of range, 720WH provides significant advantages over smaller capacities. Using a motor ranging from 250W to 500W with moderate pedal assistance on flat terrain yields estimates of approximately 30-50 miles per charge cycle. Adding more aggressive throttle input increases current draw through the motor resulting in estimated ranges decreasing to approximately 15-25 miles when using a motor rated at 750W or higher.
These estimates represent general guidelines due to variability associated with rider weight, terrain, and level of pedaling effort.
Based on this information, we estimate that daily commuters requiring coverage of distances greater than 20 miles round-trip will easily exceed this distance using this pack alone.
To compare this pack to others in the market place with more extensive customer histories, please refer to our Battery Comparison Table.
If you wish to learn more about other ebike-related products, please review our Gear Reviews Section.
If you feel confident moving forward with purchasing this pack, check the LGNUO 36V 20Ah on Amazon for the latest price.
Frequently Asked Questions
What size motor can I use with this battery?
This battery is designed for use with motors sized between 100 W and 800 W. The inclusion of a 30 A BMS ensures adequate cooling margin for sustained high-current output associated with larger motors. Based on nominal voltage and amp-hour ratings specified earlier, this translates to an approximate theoretical peak output rate of about 1 kW.
How far can I ride on a full charge?
We estimate approximately 30-50 miles when cycling on flat terrain using moderate pedal-assist inputs with motors sized in the vicinity of 250 W to 500 W. We estimate approximately 15-25 miles when cycling uphill aggressively on hilly terrain using motors sized in excess of 750 W.
How long does it take to charge?
The manufacturer-provided charger charges at a rate of approximately 2 A at 42 V. This results in a full charge taking approximately 10 hours when starting from an empty state. Since most users do not allow their batteries to become completely depleted prior to re-charging them again, actual charging times are generally significantly less than the maximum stated time.
Is this battery waterproof?
Yes, although it does not meet strict definitions of submersible, it has been rated to IP54 standards. Therefore, it should withstand typical wet weather conditions including rainfall, however it should be kept away from puddles and stream crossings.
Will this battery work on my 48 V ebike?
No, this is a 36 V ebike battery that requires compatible controllers. Attempting to connect it directly to your existing 48 V ebike setup is not correct.
What is the price per watt-hour?
This pack works out to one of the lowest costs per watt-hour among options that offer similar capacity and protection, placing it squarely with the least expensive packs you can buy at this size.