Ebikes with a 4-pin hailong battery slot just lost a pack that was built for them: the KUSAYLA 48V 20Ah has left Amazon. Shopping for a replacement now means starting from a spec sheet instead of a product page. That's less of a loss than it sounds, because the listing's title carried the whole checklist in one line: indicator light, safe lock, USB port, 4-pin base, XT60 plug.
Most listings bury those details in bullets or leave them out, and the differences show up after the pack arrives. A charge readout you didn't get, a lock that doesn't turn, a discharge connector that doesn't match your controller. Each one is a two-minute check when you know to look, and a return when you don't.
Below, the recorded spec sheet gets walked item by item, with real numbers on what 960 watt-hours means in miles and charging hours, plus why the 4-pin contact matters more than the brand on the case. Hold any live listing you're weighing against it.
The short verdict first: the pack was a mid-priced 960Wh frame battery with no buyer rating on record, so the spec sheet was always the main thing it had going. The specs survive even though the listing doesn't. Its 5-pin twin has a separate connector guide if your frame turns out to take five contacts.
The title recorded everything worth knowing
Break the recorded title into its parts and each one is a check you can run on a replacement. Indicator light: a charge readout on the case, so you can see the state of charge without powering up the bike. Safe lock: a keyed lock that holds the pack in the frame slot.
USB port: the phone-charging extra some hailong cases carry. Four-pin base: the frame connector this pack was built for. XT60 plug: the discharge connector that feeds the controller.
None of those are exotic features. They're the difference between a case that works with your daily routine and one that fights it, and they're exactly the items a sparse replacement listing omits. The recorded title proves a seller can state all of them in one line, so a listing that won't state them at all has told you something.
The numbers on the label
Forty-eight volts times 20 amp-hours is 960 watt-hours, which put the pack near the middle of the more than 300 batteries we track by price per watt-hour in the battery comparison table.
Not a standout bargain, not a premium listing. No buyer rating was ever recorded for it, and no review text either, so the honest position is that nobody outside the factory knows how these packs age.
The BMS was recorded at 30A continuous with a 75A peak, and the motor compatibility claim ran from 0 to 1800W. Hold that thought for the arithmetic below, because the claim and the BMS don't fully agree.
What 960Wh means in miles
Per em3ev's 48V 20Ah guide, a 960Wh pack runs roughly 30 to 40 miles on throttle only, and 50 to 65 miles on low pedal assist. Those are the category's planning numbers for the capacity, not a test result from this specific pack, and your terrain will move them. A 20-mile round-trip commute fits comfortably either way, with charging every two or three days rather than every night.
Charging a 20Ah pack
Twenty amp-hours is about 10 hours from empty on the 2A chargers many listings include, about 7 on a 3A charger, and about 4 on a 5A unit.
The charger amperage the KUSAYLA shipped with was never recorded, so check what any replacement includes before assuming overnight charging works. One thing isn't optional: the charger must output 54.6V, the full-charge voltage of a 48V lithium pack, and a charger built for 36V or 52V doesn't belong anywhere near it.
Why the 4-pin contact matters
Hailong cases share the same outer dimensions across pin counts, and a parts supplier that stocks the cases lists three contact layouts for the same shell: 4 blade contacts, 5 golden round contacts and 6 round contacts. A 4-pin pack in a 5-pin frame doesn't seat and doesn't connect, and no amount of wishing changes the count.
So before ordering any replacement, photograph the base of your old battery and count the contacts in the frame slot. Four flat blade contacts confirm you're shopping in the right column. The 5-pin twin of this pack has its own article, because its buyers face a harder search: 5-pin bases show up in fewer listings, and some sellers leave the pin count unstated.
Finding a live replacement with the same spec sheet
Start the search from the specs, not the brand. A query like 48v 20ah hailong 4 pin surfaces packs built for the same slot, and then the checklist does the sorting: a stated 4-pin base, a 54.6V charger or at least a named charger voltage, a BMS continuous rating you can divide by 48V, and photos that show the base and the discharge plug rather than hiding them.
On that last item, the recorded KUSAYLA spec gives you a reference point. Thirty amps continuous is 1,440W at 48V, so a 750W or 1000W motor sits well inside it.
The 1800W claim in the old title would have needed 37.5A sustained, above the 30A continuous rating, which is why the honest sustained band for this spec set tops out at 1,440W and the peak rating covers only brief acceleration spikes. A replacement quoting big motor numbers with a small continuous BMS is making the same move.
Frequently Asked Questions
Can I still buy the KUSAYLA 48V 20Ah 4-pin battery? No. The listing returns a page-not-found error and no live KUSAYLA battery has reappeared under the brand. The spec sheet above is the record, and the comparison table shows what's live now.
What's the difference between the 4-pin and 5-pin versions? Only the base connector. Both packs recorded the same 960Wh core specs, but the contacts differ, and they don't interchange. Count the contacts in your frame slot before ordering either.
Did this pack really have a USB port? The recorded title says so, and the 5-pin twin's record doesn't mention one. Treat the USB port as variant-specific, and confirm it in a replacement's photos rather than assuming it carries over.
Can a 30A BMS run a 1800W motor continuously? No. Thirty amps at 48V is 1,440W continuous. Sustaining 1800W would draw 37.5A, above the continuous rating, so treat 1,440W as the honest ceiling and the 75A peak as good for short bursts only.
What should I check before ordering any replacement? Pin count on the base, discharge plug type, charger voltage at 54.6V, BMS continuous amps divided by 48V against your motor, and case dimensions against the frame slot. Five checks, five minutes, and every one of them is cheaper than a return. Our other battery reviews cover the live packs in depth.