The short answer
Branded replacement e-bike batteries from UK dealers cost £399.99 to £999.99 for 400Wh to 800Wh packs when we read 12 listings on 22 October 2026. That is £0.79 to £2.00 per watt-hour, with a middle of about £1.24 (Look Into, checked 22 October 2026).
Generic packs sold on Amazon UK come in at a middle of about £0.22 per watt-hour, roughly a sixth of the branded price. But none of the 15 we read names a safety standard, and more than half are described as suiting motors above the legal 250W.
This page is a dated price read, not a shopping list. It carries no affiliate links: where a price is the research, we do not earn from it. Prices were read at each retailer on 22 October 2026 and will change; stock was often limited.
Prices and specs last checked by Look Into on 22 October 2026 · next check 20 January 2027 · how we picked
Branded replacement batteries: prices read 22 October 2026
| Battery | Capacity | Price | Per Wh | Retailer | Note |
|---|---|---|---|---|---|
| Shimano STEPS BT-E8035 | 504Wh | £399.99 | £0.79 | Westbrook Cycles | Reduced from £659.99 |
| Shimano STEPS BT-E8010 | 504Wh | £529.99 | £1.05 | Canyon | Members-only product |
| Bosch PowerPack 400 rack (Smart System) | 400Wh | £530.27 | £1.33 | Trek Store UK | In stock |
| Bosch PowerPack 500 rack | 500Wh | £649.00 | £1.30 | All Terrain Cycles | Out of stock |
| Bosch PowerTube 500 | 500Wh | £649.99 | £1.30 | e-bikeshop | Out of stock |
| Shimano STEPS BT-E8036 | 630Wh | £737.99 | £1.17 | Westbrook Cycles | Reduced from £819.99 |
| Shimano STEPS BT-E8036 | 630Wh | £758.49 | £1.20 | All Terrain Cycles | Reduced from £819.99 |
| Fazua Ride 60 Energy | 430Wh | £769.99 | £1.79 | Canyon | Members only; Ride 60 system only |
| Bosch PowerTube 625 | 625Wh | £799.99 | £1.28 | e-bikeshop | Out of stock |
| Bosch PowerTube 750 (Smart System) | 750Wh | £855.99 | £1.14 | All Terrain Cycles | Mounting kit not included |
| Bosch PowerTube 800 (Smart System) | 800Wh | £919.99 | £1.15 | e-bikeshop | Out of stock; only for customers who bought their bike there |
| Yamaha InTube 500Wh | 500Wh (spec table says 468Wh) | £999.99 | £2.00 | e-bikesdirect | Out of stock; fixing plates not included |
Per Wh = price divided by stated watt-hours, for example £799.99 / 625Wh = £1.28. Where a page gave two capacities we used the one in the product name and note the conflict. One own-brand spare (Basis, for three e-bikesdirect models) was listed at £299.99 to £399.99 for 324Wh or 504Wh, without saying which price goes with which size, so it is left out of the per-Wh figures (e-bikesdirect).
Two things the table cannot show. Branded batteries are rarely interchangeable: Bosch's PowerTube 600 and 800 do not fit bikes built for the 500, 625 and 750, according to e-bikeshop, and the Fazua pack only fits the Ride 60 system. And some dealers sell loose batteries only to customers who bought the bike from them.
Generic packs on Amazon UK: cheaper by a factor of about six
We read the first 15 unsponsored Amazon UK results for "e bike battery 48v" on 22 October 2026. Leaving out one listing that sells several capacities under one price and one that covers 24V to 48V in one listing, 13 had a single stated capacity and price:
- Typical price per Wh: about £0.22, with most between £0.19 and £0.28.
- Two listings claim capacities that would cost under 8p per Wh, including a "48V 50Ah" (2,400Wh) pack for £55.00. We would not rely on a capacity claim that cheap.
- Most come with a charger, and several are universal shapes (triangle, "kettle" and rack packs) sold for conversion kits rather than for a named bike.
And across all 15 listings:
- 8 of 15 describe the pack as suiting motors above the 250W legal limit, up to 2,000W.
- All 15 mention a battery management system (BMS). None of the 15 names any safety standard: no BS EN 50604-1, no EN 15194, no UN 38.3, and no UKCA or CE marking in the listing text.
The government's statutory guidelines on e-bike battery safety cite BS EN 50604-1 and BS EN 15194, and say a battery must include safety mechanisms such as a BMS to prevent thermal runaway. They cover batteries for conversion kits and online sales (OPSS). A listing that does not mention a standard has not necessarily broken it, because the standard is the seller's duty, not the listing's. But a buyer cannot check what is not stated. See e-bike battery fire safety for the official fire figures.
What a battery adds to every mile
A battery wears out with use, so part of its price is a running cost. Shimano states 1,000 full charge cycles for its BT-E6010 and BT-E8014 packs, after which more than 60% of the capacity remains (Shimano). We found no cycle figure on any Bosch page, and no maker figure for Yamaha.
The working, for a 504Wh Shimano pack at £529.99 used at Cycling UK's ballpark of 10Wh per km (Cycling UK):
- One full cycle: 504Wh / 10Wh per km = about 50km.
- 1,000 cycles: about 50,400km, or 31,300 miles.
- Battery cost per mile: £529.99 / 31,300 miles = about 1.7p per mile.
Applying Shimano's cycle figure from its other packs to this one is our assumption, and the battery is weaker towards the end, so treat 1.7p as a floor. Electricity for the same mile is about 0.42p (see what it costs to charge an e-bike). The battery is the bigger running cost by about four times.
Is a new battery worth it?
That depends on the rest of the bike. A £650 to £900 battery on a bike worth £800 is a hard sum; on a £3,000 bike with a sound motor and frame it is often the cheapest way to restore range. For bikes bought on Amazon at a few hundred pounds, the pack is usually a generic one, and the question becomes whether you can get a matching replacement from the seller at all. Ask before you buy the bike.
Signs a battery is ending are covered in each maker's own guidance; the clearest is range falling well below what the bike did when new on the same route and assist level.
What this page could not check
- Stock and availability on the day you read this. Several branded packs were out of stock on 22 October 2026.
- Whether any Amazon pack's stated capacity is real. We read the listings; we did not test the batteries.
- Real-world cycle life. Only Shimano publishes a figure, and only for some packs.
- Compatibility with your bike. Check the exact part number with the maker or the shop that sold you the bike.
Changes to this page
- 22 October 2026: page published with 12 branded dealer prices and 15 Amazon listings read that day.