What are Zero Motorcycle logs?

Zero Motorcycles store diagnostic data in binary log files (MBB and BMS). The MBB (Main Bike Board) log records riding data — motor, controller and ambient temperatures, motor RPM, the odometer and system events. No Zero log of any generation records road speed; where a speed appears it has been derived from motor RPM. The BMS (Battery Management System) log tracks battery state: cell voltages, pack voltage, current and state of charge.

What is a healthy battery balance reading?

The B field in a BMS log line is the cell spread: the highest cell minus the lowest, H minus L, in millivolts. Our diagnosis engine reads up to 40 mV as excellent and up to 80 mV as still within normal range; 80 to 120 mV is a moderate imbalance worth watching over time, and above 120 mV is significant — try a full balancing charge, and see a dealer if it persists. Do not work the spread out by subtracting the lower-case l: that is a separate open-circuit reading, not the pack minimum.

How does regenerative braking work on a Zero?

When you release the throttle or brake, the motor becomes a generator, creating resistance while converting kinetic energy back to electrical energy stored in the battery. This appears as negative amps in the logs while the bike is in motion.

What SOC range is best for battery longevity?

For daily use, charging to 80-90% SOC is optimal. Avoid leaving the battery at 100% or below 10% for extended periods. Occasional full charges help with cell balancing.

What do Zero Motorcycle error codes mean?

Zero error codes are recorded by the MBB (Main Bike Board) and BMS (Battery Management System). Common categories include controller faults, motor issues, battery warnings, and communication errors. Most are informational, but critical errors may require dealer attention.

How long do Zero Motorcycle batteries last?

Zero does not publish a cycle-life rating in any owner manual we hold, so a specific "N cycles to 80%" figure — including the one this page used to carry — has no source at Zero. What can be measured is state of health: this tool estimates a pack's usable capacity from charge energy divided by the state of charge gained, and flags a pack below 70% of expected capacity for attention and below 50% as critical. The manuals' own longevity advice is to avoid unnecessary 100% charges once the pack is calibrated, and not to leave it sitting full or near empty; temperature and storage state of charge are the main levers.

What is the Zero battery configuration?

Zero's street and off-road packs are built 28 cells in series (28S), which puts them near 102 V nominal (28 x 3.65 V) and about 117 V at full charge (28 x 4.2 V). The manuals call the chemistry "Z-Force Li-Ion" and do not name the cathode. Pack sizes run from 2.8 kWh (the ZF2.8 brick on the early FX, XU and MX) to 17.3 kWh (the ZF17.3 on the DSR/X and the 2023-on SR/F and SR/S), with an optional Power Tank adding 2.8 or 3.6 kWh on top. The 2026 light line is a different architecture: the XB's manual gives a 74 V, 2.4 kWh pack.

Zero Motorcycle Knowledge Hub

Understanding Your Zero's Data

Learn how your Zero Motorcycle's diagnostic systems work. From battery chemistry to log file parsing — everything explained for riders and enthusiasts.

How Energy Flows

Click the buttons to see how power moves through your Zero in different modes

Grid

Charger

BMS

Cells

Controller

Motor

Discharging Mode

Battery power flows through the controller to the motor for propulsion

Based on Zero Motorcycles power architecture. The Sevcon controller manages power flow between the battery and the IPM motor.

Zero Motorcycle Evolution

From 2010 to today — click each generation for details

These are product generations, taken from Zero's own owner manuals. Which log format your bike writes is a separate question and does not line up model-for-model — the FXE below is a Cypher II motorcycle whose log our parser sends to the Gen3 decoder, and the S, SR, DS and DSR kept their names across the 2024 platform change. Gen2 vs Gen3: Log Differences separates the three senses.

Before the manuals

Partial Support

2010 – 2013

Zero SZero DSZero XZero MX+1 more

Generation 1 · XMX modular

Fully Supported

2014 – 2025

Zero FX (2014-2025)Zero FXS (2016-2021)

Generation 2 · Cypher II

Fully Supported

2014 – 2023 (FXE to 2025)

Zero SZero SRZero DSZero DSRZero FXE (2022-2025)

PLATFORMS

SDS · Z-Force (Cypher II)XMX · modular (Cypher II)

CONTROLLER

Sevcon Gen4

KEY FEATURES

•Z-Force® IPM motor and the bonded street pack
•Power Tank accessory option (2.8 kWh, then 3.6 kWh)
•Charge Tank for faster charging
•Bosch ABS on the later bikes
•Onboard charger 1.3 kW, rising to 3.0 kW on the 2022-23 SR
•The FXE is a Cypher II bike in an FX body — our parser still routes its log to the Gen3 decoder
•The 2014 SR (14.2 kWh) and 2015 SR (13.6 kWh) manual sheets list maxima that carry no ZF badge in our pack catalogue

BATTERY OPTIONS

ZF11.4 / ZF12.5 / ZF13.0 (2014-17)ZF14.4 (2018-23)ZF15.6 (SR, 2023)ZF7.2 (S, DS, FXE)+ Power Tank 2.8 / 3.6

Log Support: Fully Supported

|Error Codes: Dash codes 00-63, Sevcon Gen4

Generation 3 · FST / Cypher III

Fully Supported

2020 – present

Zero SR/F (2020+)Zero SR/S (2020+)Zero DSR/X (2023+)Zero S/F+1 more

Generation 3 · light line

Unknown

2026

Zero LS1Zero XEZero XB

Logs supported — real files of this kind in our test corpus

Partial — a decoder exists, but no file to test it on

Unknown — never seen one; send us a log

Error codes differ between generations. See the Error Codes Guide and select your generation.

What are Zero Logs?

Zero Motorcycles store diagnostic data in binary log files on the bike's internal systems. These files contain detailed records of battery performance, riding data, charging sessions, and system events.

MBB Logs (Main Bike Board)

Motor control, temperatures, speeds, and system events

BMS Logs (Battery Management System)

Cell voltages, SOC, charging data, and battery health

Learn more about log extraction at ZeroManual - Interfacing

Sample BMS Log Entry

level 001 AH, SOC: 97%, I: 0A
L:4089, l:4076, H:4092, B:003
PT:017C, BT:031C, PV:114540
M:Bike On

This single entry contains: battery level, state of charge, current draw, cell voltages, temperatures, and operating mode.

The four cell fields are the ones people misread. H and L are the highest and lowest cell right now, under whatever load is present; B is the spread between them, H − L — here 4092 − 4089 = 3 mV. The lower-case l is a separate open-circuit reading and is never part of that subtraction: use it and you get 16 mV, which is not what the BMS reported. Every field, hover by hover.

Deep Dive Topics

Explore each aspect of your Zero's data in detail

Gen2 vs Gen3: Log Differences

Technical deep-dive into log format differences, ring-buffer limitations (a parked Gen3 fills the buffer in about 3 days) and binary analysis.

Why Your Gen3 Log Shows No Rides

Plain-English guide to the Gen3 ring buffer: why data disappears, how to recognise an overflowed log, and how to export before it does.

Gen3 Log Format: the 0xB2 Record Spec

Byte-level specification of the Gen3 Cypher III binary log: 0xB2 record framing, the MBB 0x51/0x54/0x52 and BMS 0x4B/0x4D/0x4C record maps, the 538XX firmware variant, and the measurement behind every offset.

How Zero Logs Work

What MBB and BMS log files contain, how they are parsed, and how the data is structured.

Anatomy of a Zero Log, Line by Line

Real extracts from real Zero log files, arranged as annotated windows across every decode route the parser has: switching on, riding, charging, parked, a fault and switching off. Every line says which board wrote it — main board or battery management — and whether the words are the motorcycle’s own or our decode of the bytes.

Phone Apps for Recording a Ride

Which iOS and Android apps you can record a ride with and upload here — and which of them capture lean angle and lateral G rather than position alone. Most apps export standard GPX, which has always worked.

Console Log Extraction (PuTTY)

Step-by-step serial-console guide: DIY cable pinout, baud rates per generation, PuTTY session logging, eventlogdump and errorlogdump — the way to get your full history as text when the binary cannot be read.

Zero VIN Decoder: All 17 Positions

Position-by-position Zero VIN reference with every lookup table published as HTML — the 538 and PAG WMIs, model-line and motor codes, the 49 CFR 565 check digit, all model-year codes, plus a decoder that runs entirely in the browser.

Battery Fundamentals

Li-ion chemistry, what the BMS does, and how SOC, voltage and cell balancing relate.

Charging Explained

CC/CV phases, onboard versus supplemental charging, and how to read a charge log.

Riding & Regen Data

Power consumption, regenerative braking and thermal management as they appear in the logs.

Reading Your Logs

Symptom-first diagnostics: twenty symptoms traced from the log line to a conclusion, including the ones no log can see.

Error Codes Guide

Searchable database of MBB and BMS error codes with causes and solutions.

Log Error Catalog

Curated error and warning families found in Zero MBB/BMS logs, each with component, category, severity, likely cause and recommended action.

Battery Health & Degradation

How lithium-ion cells age, what drives degradation, and how to read and preserve state of health — including how the app measures usable pack capacity from your own charges.

Buying a Used Zero: What the Logs Prove

What a used Zero’s own logs can and cannot tell a buyer: the four condition checks this site publishes, each one a distance from a limit Zero itself states — battery health against the 80% warranty threshold, charge discipline against the onboard charger rating, thermal exposure between the 50 °C at which the BMS stops allowing charging and the 60 °C at which it turns the power controller off — why isolation can never be scored for anybody, why the whole index is withheld rather than averaged when the battery check cannot answer, and the five things no log records at any mileage.

Temperature Limits and Derating by Platform

What temperature actually stops a Zero, separated into the five different figures the manuals state for it: 352 figures out of 35 official manuals across 10 thermal regimes, model years 2015-2026, each with its document and page. The widely copied -30 C is a cell-chemistry floor from the storage chapter, not a cutoff — the BMS acts at -5 C or -20 C depending on model year — and charging stops at 50 C while riding continues to 60 C.

Record a Ride With Your Phone

A Zero has no GPS, so route, elevation, lean and cornering can only come from something you carried. How to record a ride with Sensor Logger, which sensors matter, and what the app derives from them.

Zero Torque Specs by Model Year

Every Component Fasteners torque Zero publishes for model years 2015-2026, read out of the official owner manuals with the document and page behind each row — plus the nine figures Zero changed between model years, and the rows where its own imperial and metric values are not the same torque.

Zero Drive Belt: Tension, Alignment and What Changed

Every drive-belt figure Zero publishes for model years 2015-2026: four separate tension windows across 84 model years and 37 manuals, with the document and page behind each one — plus the 29 model years for which the widely circulated 42.5-73.6 Hz band is too slack, why the swingarm marks are not the final alignment check on a Gen3 bike, and a correction to this site’s own per-model belt data.

The 12 V System: DC/DC Converter, Fuses and the PDU

Where a Zero’s 12 V power comes from and where its fuses are, model years 2015-2026: 343 fuse rows from 68 tables in 35 official manuals with the document and page behind each one. Gen2 has a fuse per circuit; Gen3 replaced ten of them with a Power Distribution Unit, so there is no headlight fuse and no accessory fuse on an SR/F to find — plus the fifteen dash codes that report a 12 V circuit instead, and the three converter figures Zero has never published.

Telemetry Export for Video

CSV and GPX exports for Telemetry Overlay, RaceRender, Garmin VIRB and Insta360 — overlay your Zero metrics on ride footage.

Tools and Catalogues

Four things you can use right now — no account, and for two of them, no log file

Log reader

Drop a .bin export and read it as plain text. It decodes on your own machine — nothing is uploaded.

Range calculator

What a model actually goes at your speed, load, temperature and gradient — as a band, not a false decimal.

Model catalogue

Every Zero model and year: specifications, owner guides and a side-by-side comparison.

Battery catalogue

Every Zero pack: capacity, the models it shipped in, and which packs it is compatible with.

Quick Reference Glossary

Common terms you'll encounter in Zero log data

SOC(State of Charge)

Wiki

Battery percentage remaining

SOH(State of Health)

Wiki

Battery capacity compared to new

BMS(Battery Management System)

Wiki

Controls charging and monitors cells

MBB(Main Bike Board)

Central controller for motor and systems

Vpack(Pack Voltage)

Wiki

Total voltage of battery pack

NMC(Nickel Manganese Cobalt)

Wiki

A lithium-ion cathode chemistry. Zero's manuals call the pack "Z-Force Li-Ion" and never name the cathode, so treat NMC as the community's attribution, not Zero's

28S(28 Series)

Zero cell configuration (28 cells in series)

Regen(Regenerative Braking)

Wiki

Energy recovery during deceleration

CC/CV(Constant Current/Constant Voltage)

Wiki

Charging phases

Community Resources

Additional resources from the Zero Motorcycles community

Unofficial Zero Manual

Community-maintained wiki with extensive technical documentation, service manuals, and troubleshooting guides.

Visit ZeroManual.com

Official Zero Resources

Official owner resources, charging recommendations, firmware updates, and warranty information.

Zero Owner Resources

This is an educational resource created by the Zero community. For official information, visit zeromotorcycles.com. Technical details reference the community-maintained Unofficial Zero Manual.

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