Replacement battery (UL only)
Buy a spare or replacement pack only from your bike's maker, with its UL certification or UL testing stated. Skip no-name lookalike packs.
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A spare or replacement battery should come from your bike's maker, fit your model exactly and state the UL standard it is certified or tested to. UL 2271 covers e-bike battery packs; UL 2849 covers the whole e-bike electrical system. Each pick below lists exactly what its maker states.
Check the compatibility list before you buy, because voltage, connector and mount differ even within one brand. Store spare packs in a cool, dry place, and never use a pack that has been dropped hard, swollen or soaked.
Where to buy
Picks with a "Check today's price" button are affiliate links to the brand's store or Amazon. Editorial mentions are plain links.
Our picks
Sold by Magnum
Magnum i6 48V 15Ah replacement battery
UL certified, per Magnum (the standard isn't named on Magnum's page). Consumer Reports' battery-safety guidance says to buy UL-certified e-bikes and batteries and use the maker's charger.
Fits listed Magnum models only.
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Sold by Magnum
Magnum i6 48V 20Ah high-capacity battery
Higher-capacity genuine Magnum pack; UL certified, per Magnum (standard not named).
Check Magnum's compatibility list (not for Metro LS or Payload, per Magnum).
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Sold by Radio Flyer
Radio Flyer spare battery 48V 10Ah (Cruisers, Folding Cargo, Flex)
UL 2271 tested, per Radio Flyer, with Samsung 50E cells per the listing.
Fits listed Flyer models only.
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Pro tips from the e-bike pros
- Buy from the bike maker, not a marketplace lookalike.
- Register your bike and battery with the maker so you hear about recalls.
- Check CPSC recalls before buying any used pack.
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