The Hawkvium 52V 25Ah battery is currently the cheapest 52V pack on our list and has a real safety certification. SGS UL2271 is so rare at this price, the fact that it has the certification rather than the capacity is what makes the story. The bad news: five reviews give you very little information about what the battery will do.
What UL2271 Really Gets you
UL2271 is the specific safety standard for the battery in a light electric vehicle. While many manufacturers can attest to passing the UL2271 safety standard, they may have done so using either a variety of methods (ie. Sending their product overseas for testing). In addition to covering the overall pack (cell layout, BMS behavior, etc.) it covers the following:
- Thermal stress testing, performed by SGS as an independent lab. Most manufacturers do not pay for UL2271 due to cost.
If a pack is untested, it fails as small internal problems. Tested packs fail as a small problem at the cell level and the BMS & construction are tested to keep the problem contained. Nobody ever states that a battery will never fail. Testing means someone external to the manufacturing facility confirmed that all potential failure paths have been addressed.
Specifications
The specifications listed below show a pack holding 25 amp-hours at 52V nominal voltage. Nominal voltage = 1300 watt-hours. The pack is suitable for motors rated between 100 watts and 3000 watts, depending on how hard the motor is driven. The BMS is capable of providing 60 amps when driving a 3000-watt motor. The total weight of the pack is 13.23 pounds. Dimensions are: 14.49 inches x 3.54 inches x 5.94 inches. These are large dimensions and while most downtubes will accommodate these dimensions, none of the current generation of integrated frame designs will be able to accommodate these dimensions.
The 21700 cells represent the new standard. They are significantly more dense than the old 18650's, thus there is less space occupied per amp-hour. Additionally, 21700 cells provide far superior thermal characteristics than the older 18650 cells. According to the seller, the pack is "Grade-A" quality and provides more than 1000 cycles. He also claims that at 800 cycles the pack retains 80% capacity. The manufacturer claims are not supported by review data. Only the certification is something we can verify. Cycle life cannot be verified by reviews.
Connectors & Compatibility
Two discharge leads come with the pack. One lead is an XT60 female connector and the other lead is an XT90 female connector. As stated above, the XT90 connector is used in most high-current applications. Having both connectors allows for single-motor commuters and dual-motor configurations to utilize the pack without purchasing adapters. The base of the pack comes with a pre-installed 5-pin connector for attaching to frames.
Additionally, a power switch, safety lock, LED status indicator and anti-vibration pads come with the pack. The anti-vibration pads are useful for any application where the battery will be attached directly to a frame. Vibration caused by travel can continue to damage cell welds for years.
The Five Review Problem
This is the classic case of a perfect tiny sample size. This means that all five reviewers were satisfied with the first unit purchased from Hawkvium and we know nothing else. There is no review data regarding failure rates, cycle-life confirmation, winter range degradation, etc... The listing is part of a larger group of variants sold by Hawkvium and therefore confirm that you receive the correct model number upon receipt of your unit.
The honest statement: we like that the certification was verified by a third party, we believe that the specs appear reasonable, and we like the price. We do not have any user-based evidence yet. You are among the first to buy this battery, and as such you will be waiting until after your purchase to get all of the long term data.
Range Calculation. With a maximum capacity of 1300 watt-hours, your potential range is high. With a moderate assist setting (750W motor) you could expect 70-90 miles. On the flip-side, with a fully-powered setup (3000W dual motor) you could expect to drain it in 15-20 miles. To calculate range simply divide your watt-hours by 100 and multiply by miles-per-dollar (a rough estimate based on riding style, terrain difficulty, and throttle discipline): roughly 100 dollars /watt-hrs = ~3-5 miles/whr.
To charge, simply connect it to the included fast charger and allow it to complete its multi-stage charging cycle. Assuming your commute requires enough range for this much capacity, allowing it to charge overnight should meet your requirements.
Who This Battery is for
You: If certification is required (as a building code, an insurance policy requirement, or simply because you refuse to sleep next to an un-certified pack). You: If you operate a high-power setup and require the BMS headroom for delivering up to 60A via an XT90 connection.
You: Not you, if you want to wait until you receive long-term reliable performance data prior to making a purchase, or if your frame design requires a compact form-factor (the pack is too wide and heavy for that). This pack will NOT fit into most frame-integrated battery locations.
Compare certified and non-certified batteries on our ebike battery comparison chart, and find additional writing regarding power systems in our blog.
Frequently Asked Questions
Is UL2271 similar to UL2849?
No. UL2849 covers the entire e-bike electrical system. UL2271 only addresses battery packs themselves. Both certifications address a reduced fire risk associated with each type of certification.
Does it come with a charger?
Yes. A fast-charger comes with the pack along with two discharge leads (XT60 & XT90).
Will it fit my frame?
Use your tape measure before ordering. The pack measures 14.49 x 3.54 x 5.94 inches with a 5-pin base connector. Any frame-integrated design will likely NOT accommodate these dimensions.
Is the claim of >1000 cycles verifiable?
Manufacturer claims only. Not verified by review evidence.
Can I use this on my high-powered dual-motor setup?
The BMS is designed to handle high currents as evidenced by the 60A capability of the BMS and availability of an XT90 connector specifically for those applications (i.e., dual-motor setups).
The bottom line for anyone cross-shopping this against the rest of the Hawkvium lineup is that the spec sheet here does the specific job the listing promises, and the pricing sits where the value argument holds. Verify the exact variant on arrival, keep the packaging until you have confirmed the model number, and check fit against your actual setup before the return window closes. Most disappointment in this category traces to fitment assumptions rather than hardware failures, and ten minutes with a tape measure prevents most of it.