Total voltage from the battery is too high/low

Stop riding Last verified: pending review Reviewed by: editorial team

Quick answer

Error Code 42 indicates that the battery pack's discharge voltage is too low, which can occur under load or if the battery needs charging. This may happen especially in cold conditions or during climbs, where voltage sag is more pronounced.

Stop riding Battery Often DIY-friendly Beginner (15–30 min)

Does this apply to your bike?

H700 · Bafang · Common displays: DP E171

Heads-up: the same number can mean different things on other systems — always check your drive system first. Browse all drive systems →

What you’ll notice

The display shows Error Code 42, and the eBike may experience reduced power or assistance.

Likely causes, ranked

Start at #1 — causes are ordered by how often they turn out to be the problem.

#1 Battery Voltage Too Low

How to check: Check the battery charge level and ensure it is fully charged.

#2 Cold Weather Impact

How to check: If riding in cold conditions, warm the battery indoors before use.

#3 High Load Conditions

How to check: Test under lower assist and easier gear to see if voltage sag improves.

Troubleshooting steps

Charge the Battery

easy

Fully charge the battery and retest the system.

If it passes →Check if the error persists.

If it fails →Inspect battery connections and consider replacement.
Warm the Battery

easy

If in cold weather, bring the battery indoors to warm up before testing.

If it passes →Retest after warming.

If it fails →Charge the battery.
Test Under Load

easy

Use lower assist settings and easier gears to reduce load on the battery.

If it passes →Monitor for error code recurrence.

If it fails →Consider professional diagnostics.

When to stop and get professional help

If the error code returns immediately after charging or if there are signs of battery damage.

Never open, puncture, or disassemble the battery pack, and never bypass the BMS. See our safety guide.

More codes for H700

36 · Detection circuit on the keypad has an error 37 · WDT circuit fault 41 · Total voltage from the battery is too high/low 43 · Total power from the battery cells is too high 44 · Voltage of the single cell is too high 45 · Battery temperature is too high

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Sources & verification

Last verified: pending review Reviewed by: editorial team

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