Rad Power stopped selling replacement batteries for a lot of its older bikes, and the owners of those bikes know it. When the pack on a RadRunner or a RadExpand dies, the bike doesn't slow down, it stops. The official answer costs more than some people paid for the whole bike used, so a third party market grows around that gap.
The ShunTongDa pack reviewed here is built for exactly that gap, and the listing says something unusual right in its title: it doesn't support Rad controller firmware v1.4.0 and above. That one line, misspelled though it is, decides the purchase before price ever comes up.
The record behind it is small. Forty-three ratings, twelve written reviews, every one of them from a confirmed order, and ten of the twelve describe a Rad bike swap. What follows is that record, read closely: the fit reports, the one defect report with real detail in it, the claims the listing can't back, and the range math worth planning a ride around.
The ShunTongDa 48V 14Ah external battery is a replacement pack built for Rad Power bikes, and the fit record behind it is real: ten confirmed buyers describe direct swaps on a RadExpand 5, RadRunner 2, Rad Mini 4, RAD4, RadRover, and a post-recall RadWagon, most reusing their original cradles and keys.
The catches are a firmware cutoff the listing itself prints in its title and a price per watt-hour among the most expensive of the 301 packs we track. Whether that trade makes sense depends on which Rad bike is sitting in your hallway.
A replacement battery with a firmware warning in its own title
The listing title carries a strange compatibility cutoff, and it is even misspelled: "No Suport Upgrade APP v1.4.0."
Because this is a power-only Hailong pack that won't work with Rad controller firmware v1.4.0 or newer, owners of a Rad bike have a software check to run before they ever look at the price. Bullet 1 repeats the notice. No other listing in this category puts its most important spec in the title by accident.
The histogram is the part worth reading: 78 percent five-star and 7 percent four-star with nothing at all between three stars and one, and all twelve written reviews attached to confirmed orders.
Zero unverified texts is rare in this category.
At 280.99 for 672Wh, the /ebike-batteries/ table puts this pack near the expensive end per watt-hour. The price buys the niche rather than the cells.
Ten Rad bikes, zero modifications, three matching keys
This battery works as a direct replacement for many Rad Power models because it comes with a pre-installed base and XT-60 connectors, and the record shows buyers reusing their original cradles and brackets. One owner has found it fit both of their Rad Power bikes after both original batteries died, and the key matched one of the dead units. That text carries seven helpful votes, the most on the page.
The rest of the fit list reads like a Rad catalog. A RadExpand 5 buyer reports an exact fit using the original cradle, with the pack looking the same as the original including the keys.
The RadRunner 2 and the Rad Mini 4 are direct swaps with no baseplate switching, and the Rad Mini 4 owner notes even the key is the same. Two packs have fit a pair of RadRovers perfectly. One buyer has fitted it to a RAD4 with no modifications, and another has used it in a post-recall RadWagon on the original bracket.
The RadMission 1 case is the honest edge of the list: the pack fit properly and powered the controls and lights, but that bike's motor was seized, so the buyer returned it and reported the seller was helpful and easy to work with. Every completed swap implies firmware older than v1.4.0, and no one says which version they run, so the check stays on you.
The one defect report that deserves a close read
One owner running two of these packs on two RadRovers has reported that one pack cut power to the motor for minutes at a time while the bike readout did not falter. They suspect a connection issue between the battery and the stock controller, and the live readout is exactly why that guess is plausible. Their own closing line was a hope that it doesn't happen again far from home.
Around it sit the quiet failures. One one-star says only "Didn't work." Another October buyer describes a pack that showed power but then would not release from the bike, phrased as a question to other owners, and nothing on the page answers it.
No owner has alleged a cell failure or any thermal event, and the one completed return in the record, the RadMission case, was handled well.
The record spans March to October 2026, about six months, with nothing older. That is too short to say anything about durability, and one intermittent electrical complaint is a pattern of exactly one. Treat it as a reason to test the pack early rather than as a verdict on the cells.
Claims the listing's own numbers do not back
The listing promises a waterproof casing for all-weather durability, yet no IP code appears anywhere on the page. It lists 672W in the first bullet when it clearly means watt-hours, which is the total energy the pack holds. The range estimate of 55 to 200km per charge spans 34 to 124 miles, a window too wide to plan a commute with.
And the "faster charging" bullet's seven hours is just 14Ah divided by a 2A charger, the minimum fill time priced as a feature.
The 800-cycle claim with 80 percent retention sits above the 300 to 500 full-cycle norm for 18650 packs in deep-discharge service, and no owner has run this pack long enough to test any of it on a seven-month record. The spec table says a one-year warranty, which covers a fraction of the claimed cycle life.
Then the reverse case, which is rarer than it should be. Four buyers independently confirm a charger arrived, one describing an onboard fan, while the Included Components line lists only base, pack, and keys, so the listing under-declares its own box. The weight figures agree for once, with 7.7 lb and 3.5 kg describing the same mass.
Even the "52 A batteries required" metadata line matches 13S4P cell arithmetic, though the listing never states a configuration, so treat that as coincidence math rather than a spec.
Range arithmetic and the price of the niche
Since no owner has reported a full ride, the 672Wh capacity goes through the community energy bands instead. Minimal assist, motor only on hills, at 6-8 Wh/km gives roughly 84 to 112 km, about 52 to 70 miles.
Typical assist around 40kph with pedalling, at 9-12 Wh/km, gives roughly 56 to 75 km, about 35 to 47 miles. Throttle-heavy riding at 14-20 Wh/km drops to roughly 34 to 48 km, about 21 to 30 miles. The only mileage anywhere in the record is a buyer whose gauge did not drop a bar over 9 miles, a top-up data point, not a range claim.
Power checks out. The 30A BMS allows about 1440W continuous on a fresh pack, above the 1200W motor ceiling the listing names, so the electronics leave headroom rather than hiding a bottleneck.
At about 0.42 per watt-hour this pack is among the most expensive units we track, and the honest framing is that you're paying for the swap, not the cells. A Rad owner with older firmware gets a direct fit with matching keys and no adapter work, which a generic Hailong pack doesn't offer. Anyone with a different 48V bike should compare price per watt-hour on the /ebike-batteries/ table instead.
FAQ: the fit the firmware version decides, the charger four buyers confirm and the all-weather promise no code rates
Will it fit my Rad bike?
Two checks decide it: the controller must run firmware below v1.4.0, and the original cradle has to take this base. Ten of the twelve written reviews describe completed Rad swaps, including RadExpand 5, RadRunner 2, Rad Mini 4, RAD4, RadRover, and RadWagon.
Does it come with a charger?
The listing's Included Components line says base, pack, and keys, but four buyers independently confirm a charger arrived, one describing an onboard fan.
How long does it take to charge?
A 14Ah pack on a 2A charger needs about seven hours, which is arithmetic rather than a claim, and the listing never names its charger's amperage.
Is it waterproof?
The bullet says waterproof casing, but no IP code appears anywhere on the page, so treat the pack as unrated and keep it out of standing water.
What if it doesn't work with my bike?
The record holds one return handled well and one unanswered complaint about a pack that would not release, so buy inside the return window and test removal before riding.