Compatibility answer

Will the Shimano BT-E8035 battery (504 Wh, 1st gen) work with the Shimano DU-EP800 (EP8, 1st gen) drive unit?

Yes. Both use Shimano STEPS 1st-gen integrated battery (BT-E8035 / BT-E8036).

Both records are reviewed against the manufacturers' sources; sources last checked 2026-10-14. Informational only: confirm with the manufacturer before buying.

Why

  • ✓ Both use Shimano STEPS 1st-gen integrated battery (BT-E8035 / BT-E8036).

Good to know

  • Shimano's chart does not list these for DU-E6000/E6001/E6010/E6002/E6012.
  • BT-E8035 (14 Ah) and BT-E8036 (17.5 Ah) are different sizes; the frame must be built for the one you buy.
  • Shimano's chart footnotes that some batteries do not support drive-unit output over 500 W; check the chart for your exact combination.
  • Shimano Gen.2 (BT-EN..., used with EP801/EP600/EP500) and 1st-generation (BT-E...) components: 'With some exceptions, first-generation and Gen.2 products ... are not compatible with each other.' Gen.2 batteries and mounts are marked 'Gen.2'.
  • 'EP8' is used for both the DU-EP800 (1st gen) and DU-EP801 (Gen.2), and 'EP6' for DU-EP600 (Gen.2); check the drive-unit model number, not the marketing name.
  • Shimano: 'It is recommended to use a SHIMANO genuine battery' and 'Use the specified battery and battery charger combination for charging.'
  • The battery must also match the bike's battery mount and frame; Shimano's chart lists compatible mounts per battery. Watt-hours here are 36 V x the Ah Shimano states.
  • Safety: use only batteries and chargers the drive-system maker approves. Lithium batteries that don't match can overheat.

Sources

Check your exact setup

Other parts in the cart, current configuration (installed memory, fan brackets) and adapters can change the answer.

Check a whole cart

Also checked with the Shimano DU-EP800 (EP8, 1st gen) drive unit

Everything checked with it

AI assistants and developers: the same answer, with a signed receipt, from check_compatibility at https://tetheredtrust.com/mcp or POST https://tetheredtrust.com/v1/check with existing_id: "shimano-du-ep800", candidate_id: "shimano-bt-e8035".