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Zero Motorcycle logs, batteries and error codes, explained

Learn how your Zero Motorcycle's diagnostic systems work, from battery chemistry to log file parsing, in guides written for riders and enthusiasts.

Every guide, by shelf

Battery & charging

Battery FundamentalsLi-ion chemistry, what the BMS does, and how SOC, voltage and cell balancing relate.
Charging ExplainedCC/CV phases, onboard versus supplemental charging, and how to read a charge log.
Battery Health & DegradationHow 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 ProveWhat 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 PlatformWhat temperature 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.
The 12 V System: DC/DC Converter, Fuses and the PDUWhere 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. It also covers the fifteen dash codes that report a 12 V circuit instead and the three converter figures Zero has never published.

Riding & data

Phone Apps for Recording a RideWhich iOS and Android apps you can record a ride with and upload here, and which of them capture lean angle and lateral G as well as position. Most apps export standard GPX, which has always worked.
Riding & Regen DataPower consumption, regenerative braking and thermal management as they appear in the logs.
Ride WeatherWind, gusts, humidity and rain for the hours a ride covered: the three ways to give a ride a location, why a long ride gets nothing from the town the bike is kept in, and the one thing weather may do to a fault report.
Reading Your LogsSymptom-first diagnostics: twenty symptoms traced from the log line to a conclusion, including the ones no log can see.
Record a Ride With Your PhoneA 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 YearEvery 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.
Tyres on a Zero: OEM, Pressures, ReplacementsThe tyre and the cold pressure Zero specifies for every model year, read out of the owner manuals with the page behind each figure, replacement tyres sorted by what they are built for, and why grip and rolling resistance are different things.
Zero Drive Belt: Tension, Alignment and What ChangedEvery 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.
Zero Service Schedule: Every Model, Every IntervalZero's own maintenance schedule for all 13 models, parsed out of the official manuals and drawn on a distance axis instead of listed as prose: 72 intervals and 101 torque figures, each plan citing the manual page it came from. It also explains why 6 of these schedules are printed in the owner manual rather than the service manual.
Zero Motorcycle Noises: What Each One MeansSqueals, hums, creaks and clunks on an electric motorcycle, traced to the page of the Zero manual that prints them, including the ones Zero calls normal, the belt noise that is an alignment fault rather than a lubrication one, and the chain that exists on 2 of 13 models and on no other Zero.
Zero Part Numbers: The OEM Parts Index by Subsystem1,010 Zero part numbers across 19 subsystems, each with the fitment the catalogue itself recorded. The owner manuals print none.
Zero Component Map: What Parts Carried Over, 2014-2026Which components Zero reused across models and model years, read out of its own owner manuals: 60 distinct parts across 90 model-year spec sheets, 2014-2026, with the manual behind every cell. One rear brake caliper covers nine model lines and all three hardware generations. A shared cell means the same described specification, not a matching part number (Zero’s owner manuals print none), and the entire high-voltage side is absent from them: Calex, Mean Well, Delta-Q and Elcon appear zero times in the 46 indexed manuals, so the charge path is listed separately, from the rescued community archive. Where our own specification extraction missed a row, the build reads it back out of the manual text and says which PDF page it came from.
Telemetry Export for VideoCSV and GPX exports for Telemetry Overlay, RaceRender, Garmin VIRB and Insta360, so you can overlay your Zero metrics on ride footage.

Formats & decoding

Gen2 vs Gen3: Log DifferencesA technical look at 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 RidesPlain-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 SpecByte-level specification of the Gen3 Cypher III binary log: 0xB2 framing, the 13-byte record header, the BMS flash page marker, the MBB and BMS record maps including the charger, queue and build records, the 538XX variant, and a record-by-record check against the community parser.
How Zero Logs WorkWhat MBB and BMS log files contain, how they are parsed, and how the data is structured.
Zero Motorcycle GlossaryEvery term this site uses about a Zero, such as MBB, BMS, ring buffer, state of charge, usable capacity and regen, defined once with the page behind each.
Anatomy of a Zero Log, Line by LineReal 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.
Console Log Extraction (PuTTY)Step-by-step serial-console guide: DIY cable pinout, baud rates per generation, PuTTY session logging, eventlogdump and errorlogdump. This is how you get your full history as text when the binary cannot be read.
Zero Bluetooth Protocol: Commands and RepliesHow a Zero talks over Bluetooth: Gen2 on Classic SPP and Gen3 on Bluetooth LE, no login, one CRC-32 frame shape, every known command with what its reply holds and in which unit, a whole log download block by block, and the commands that change the motorcycle, drawn from real captures of a 2016 FXS.
Zero VIN Decoder: All 17 PositionsPosition-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 and all model-year codes, plus a decoder that runs entirely in the browser.

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 motor controller (a Sevcon on Gen1 and Gen2 bikes) manages power flow between the battery and the 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, but 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
Fully supported: real files of this kind are in our test corpus
Partial support: a decoder exists, but we have no file to test it on
Unknown: we have never seen one, so 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, motor RPM, 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.

Tools and Catalogues

Four things you can use right now without an account. Only the log reader needs a log file.

Quick Reference Glossary

The terms you meet first in Zero log data. All 38 are defined in the full glossary.

MBB(Main Bike Board)

The motorcycle’s main controller. It supervises the motor, the dash and the interlocks, and it writes the MBB log, the file that holds rides, faults and, on most generations, the odometer.

BMS(Battery Management System)
Wiki

The board inside the battery pack. It measures every cell, decides what charging and discharging the pack will allow, and writes its own separate log. A bike with two packs has two of them, each with its own log.

Ring buffer
Wiki

A store of fixed size that overwrites its own oldest record once it is full, so a log always holds the most recent history and never the whole of it. A parked Gen3 bike fills its buffer in about three days, which is how a rider ends up with a log that shows no rides at all.

Dash code

The number the instrument cluster shows the rider. It is one of three separate vocabularies: a Gen2 diagnostic trouble code and a Gen3 error code with the same number are unrelated to each other, and the words a log file writes are a third set again.

SOC(State of Charge)
Wiki

How full the pack is right now, as a percentage. The logs record it as a whole number, so a ride that really used 1.4% is written down as 1, which is why a percentage this small cannot carry a capacity estimate on its back.

SOH(State of Health)
Wiki

What the pack holds now against what it held when new, as a percentage. The number is only as good as its denominator, so this site states which one it used: the badge, the usable-when-new figure, or a measurement.

Usable capacity

What a rider can draw, which is lower than either published figure: a BMS keeps a reserve at both ends of the pack. This site values it at 0.88 of the badge, the ratio backed by all 22 packs in Zero’s own catalogue, which run between 0.8718 and 0.8929.

28S(28 cells in series)

The architecture of every pack in this catalogue: 28 cells in series, about 102 V nominal and about 117 V fully charged. The 2026 light line (LS1, XE, XB) is a different architecture at 74 V.

NMC(Nickel Manganese Cobalt)
Wiki

A lithium-ion cathode chemistry, and, for a Zero, a community attribution rather than a specification. Zero’s manuals name neither the cathode nor the cell supplier for the traction pack, though they do print the chemistry of the 12 V auxiliary battery, so the silence looks deliberate. Treat it as what somebody worked out, not as what Zero states.

CC/CV(Constant Current, then Constant Voltage)
Wiki

The two phases of a lithium charge: current held steady while the voltage climbs, then voltage held at the ceiling while the current tapers. The taper is why the last few percent take a disproportionate share of the time.

Regen(Regenerative braking)
Wiki

The motor used as a generator, putting energy back into the pack while slowing the bike. In a log it is current flowing the same direction as charging, which is why current alone cannot tell a regen from a wall charge. The rest of the record has to.

All 38 terms

Common questions

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. Gen1 and Gen2 logs record no road speed, and a Gen3 main board writes one only in its rarer 0x52/0x53 records; elsewhere a speed 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.

Community Resources

A community wiki and Zero's own owner resources

Unofficial Zero Manual

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

Visit ZeroManual.com (archived copy)

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, linked as its Internet Archive copy because zeromanual.com has been offline since March 2026.

Ready to Analyze Your Own Logs?

Upload your Zero's log files to see all of this applied to your own bike, or open the read-only demo first. It needs no email and holds two real, anonymized bikes.

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