Electric construction equipment telematics: reading CAN bus state of charge and run hours.

Electric construction equipment telematics is the practice of reading operating data — state of charge, run hours, charging sessions, battery temperature and health — directly from a battery-electric machine's CAN bus, and reporting it alongside the diesel machines in the same fleet. Most telematics platforms were built around a diesel data model and still show an electric excavator as a machine with no fuel and no engine.

Why most telematics platforms fail on electric machines.

The mainstream telematics data model was standardised around diesel. ISO 15143-3 (AEMP 2.0), the interoperability standard almost every OEM portal exports, defines fields like FuelUsed, FuelRemaining and EngineHours. Later revisions added a battery state-of-charge element, but adoption across OEM feeds is patchy and many mid-size platforms never implemented it.

The practical result on the yard: you buy a Volvo ECR25 Electric, a CAT 301.9 Electric or a Wacker Neuson EZ26e, plug it into the same portal as the rest of the fleet, and get a machine card showing 0% fuel, 0 L/h consumption and a greyed-out engine section. Utilisation reporting silently excludes the machine. Service planning keeps counting calendar days because no hour meter is mapped.

• Fuel-shaped data model: fields exist for litres, not kilowatt-hours
• OEM feed gaps: not every electric model publishes SoC through the public API
• No charge-session concept: refuelling is an event, charging is a state over time
• Diesel-only alerting: rules trigger on fuel drops and DPF codes, not depth of discharge

What an electric machine actually publishes on the CAN bus.

A battery-electric machine is, from a data standpoint, no quieter than a diesel one — it just says different things. The battery management system (BMS), the inverter and the vehicle controller all broadcast on CAN, typically over J1939 or a manufacturer-specific CAN profile. Read directly from the bus, a typical electric excavator exposes:

• State of charge (SoC) — the usable pack charge, as a percentage, updated continuously
• Pack voltage and current — the basis for real kWh consumption per hour of work
• Cell and pack temperature — the leading indicator for thermal derating in summer and slow charging in winter
• Run hours / key-on hours — the electric equivalent of engine hours, and the correct basis for service intervals
• Charge state and charge current — whether the machine is plugged in, charging, or finished
• State of health (SoH) — usable capacity relative to nominal, the number that governs residual value
• Fault and derate codes — thermal derate, isolation fault, contactor and inverter errors

That is more actionable data than most diesel machines expose, not less. The information exists on the wire from the moment the machine is delivered. Whether it reaches your dashboard depends entirely on whether your telematics provider reads CAN directly or only resells an OEM API.

Direct CAN bus reading vs. OEM API: why it matters for electric fleets.

There are two ways a telematics platform can obtain machine data. It can call the manufacturer's cloud API, or it can read the machine's own bus through a gateway wired into the CAN network. For diesel machines the difference is mostly latency and field coverage. For electric machines it is the difference between a working dashboard and an empty one.

• OEM API route: limited to whichever fields the manufacturer chose to publish, often refreshed hourly or daily, and frequently missing SoC entirely on smaller electric models
• Direct CAN route: every parameter the machine broadcasts, at the machine's own update rate, on any brand — including compact electric machines with no telematics subscription at all

The second route is also brand-agnostic by construction. A gateway that speaks CAN does not care whether the badge on the counterweight says Volvo, CAT, Wacker Neuson, JCB, Takeuchi, Kubota, Bobcat or Liebherr. That matters, because electric fleets are almost never single-brand — operators buy whichever electric model was available in the size class they needed, in the year they needed it.

The four numbers that actually run an electric fleet.

1. State of charge, before you dispatch

Diesel machines are dispatched on the assumption that fuel is solvable — a jerry can and ten minutes fix a bad morning. Electric machines are not. A machine at 22% SoC at 07:00 will not complete a full shift, and no amount of urgency changes that. Live SoC on the dispatch screen turns that from a mid-morning crisis into a planning decision made the night before.

2. Run hours, from the bus, for service intervals

Electric machines still have hydraulics, tracks, pins, bushings, filters and greasing points, and those wear on hours of work — not on calendar months. Because there is no engine, many fleets fall back to date-based servicing and either over-service a machine that ran 40 hours in a quarter or under-service one that ran 600. Run hours read from the vehicle controller restore hour-based maintenance to the electric part of the fleet.

3. Charging sessions, overnight

The single most common electric-fleet failure on a European site is a machine that was plugged into a socket that had no power, or unplugged by someone who needed the outlet. Nobody notices until 06:30. A charge-session record — started, stopped, duration, energy delivered, final SoC — makes that visible the moment it happens, and lets you shift charging into off-peak tariff windows on purpose rather than by accident.

4. State of health, over quarters

The battery is the single most valuable component in an electric machine and its degradation curve determines residual value at resale or end of lease. Tracked from day one, SoH gives you a defensible number in a remarketing conversation and an early warning when one machine in the fleet is degrading faster than its siblings — usually a sign of habitual deep discharge or repeated fast charging in high ambient temperatures.

Running a mixed diesel–electric fleet on one screen.

Almost no contractor is fully electric, and almost none will be for a decade. The realistic fleet for the next ten years is mixed: diesel excavators over 15 tonnes, electric compacts and telehandlers in urban and indoor work, and a rented genset somewhere in between. The operational requirement is not an electric dashboard — it is one dashboard where drivetrain is an attribute, not a separate product.

That means normalising to shared concepts at the event layer:

• Energy remaining — litres of diesel and percent SoC both answer 'can this machine finish the shift?'
• Run hours — engine hours and key-on hours both drive the same service rules
• Utilisation — working, idling and off apply identically to both drivetrains
• Cost per hour — diesel at a price per litre, electric at a price per kWh, compared in the same report
• Faults — an SPN/FMI code and a thermal derate code both route into the same triage and the same work order

Once those five concepts are shared, an electric machine stops being an exception. It appears in the same fleet list, the same utilisation report and the same maintenance queue as everything else.

The electric-fleet business case nobody models properly.

Electric machines carry a purchase premium of roughly 1.5–2x their diesel equivalent, and the payback case rests on energy cost, maintenance and access to low-emission zones and tenders that require them. Every one of those variables is measurable only if you have the machine's own data:

1. Energy cost per working hour — kWh consumed per productive hour, at your actual tariff, versus litres per hour on the diesel machine it replaced
2. Maintenance delta — no oil, filters, DPF or regeneration events, tracked as work orders that never got created
3. Utilisation — whether the electric machine is actually being used or is parked because operators do not trust the range
4. Compliance value — hours worked inside zones or on contracts that a diesel machine could not have entered

Fleets that cannot produce these numbers tend to stop after the first electric machine. Fleets that can tend to buy the second and third.

Frequently asked questions.

Can you get telematics on an electric excavator?

Yes. Electric excavators broadcast state of charge, pack voltage, temperature, run hours and fault codes on the CAN bus. A CAN-capable telematics gateway reads them directly, regardless of brand and regardless of whether the machine has an active OEM telematics subscription.

How do you track engine hours on a machine with no engine?

You track run hours — key-on and operating hours reported by the vehicle controller. They serve the same purpose as engine hours: they drive hour-based service intervals for hydraulics, undercarriage and greasing, and they are the correct denominator for utilisation and cost-per-hour reporting.

Why does my telematics portal show 0% fuel on an electric machine?

Because the platform's data model was built for diesel and it has mapped no field to state of charge. The machine is publishing SoC on the bus; the portal is looking for litres. Reading the CAN bus directly, or mapping SoC into the same 'energy remaining' concept, resolves it.

Can diesel and electric machines be managed in the same system?

They should be. Utilisation, run hours, faults, work orders and location are drivetrain-agnostic. Only the energy unit differs — litres versus kilowatt-hours — which is a formatting question, not an architectural one.

Does reading the CAN bus void the machine warranty?

A correctly installed telematics gateway reads the bus passively and does not transmit onto it. Passive listening on a dedicated diagnostic or piggyback connection is standard practice across the industry. Ask any vendor to confirm read-only operation in writing, and use installers who know the machine's harness.

What to ask a telematics vendor about electric machines.

1. Show me a live electric machine in your product — not a slide.
2. Do you read state of charge from the CAN bus, or only from the OEM API?
3. Which electric models are already mapped, and what happens with one you have never seen?
4. Do you record charging sessions as discrete events with energy delivered?
5. Do you trend state of health over time, and can I export it for a remarketing report?
6. Do electric machines appear in the same utilisation and cost-per-hour reports as my diesel machines?

The short version.

1. Electric machines are not data-poor — most telematics platforms are just diesel-shaped
2. State of charge, run hours, charge sessions and state of health are the four numbers that matter
3. Direct CAN bus reading beats OEM APIs on coverage, refresh rate and brand independence
4. Mixed diesel–electric fleets need one event model, not two dashboards
5. The electric business case only closes if you can measure energy per hour and real utilisation