Offline Electrical App — Work Without Signal, Never Lose Data

Electricians do not work in offices with reliable Wi-Fi. They work in meter cupboards, basement plant rooms, industrial units, rural farmhouses, underground car parks, and new-build sites where the mast has not been erected yet. Any app that requires a constant internet connection will fail you in exactly the situations where you need it most.

This is not a minor inconvenience. If you are halfway through an EICR and your app loses connection, you risk losing test data, having to re-enter readings, or being unable to complete the certificate at all. For electricians working to tight schedules — often completing 3-5 EICRs per day — any downtime caused by connectivity issues is directly lost income.

Elec-Mate was designed from the ground up with offline-first architecture. The app does not merely "cope" with poor signal — it works identically whether you have full 5G coverage or no connection at all. The only features that require connectivity are AI-powered tools that process data on cloud servers.

All 16 certificate types in Elec-Mate work fully offline. You can complete the entire certificate workflow without any internet connection:

• Enter property details, client information, and installation particulars
• Record supply characteristics and earthing arrangements
• Fill in circuit schedules with device types, ratings, and cable sizes
• Enter all test results — continuity, insulation resistance, polarity, Zs, RCD
• Record observations with C1/C2/C3/FI classification codes
• Capture digital signatures from inspector and client
• Generate PDF certificates for local storage

Whether you are completing an EIC, Minor Works, or any other certificate type in the digital certificates app, the offline experience is identical to the online experience. Test result validation against BS 7671 maximum values also works offline — the validation tables are stored locally on your device.

Every calculator in Elec-Mate runs entirely on your device. There is no server round-trip, no API call, and no dependency on internet connectivity. All 70+ BS 7671 calculators work offline with identical performance:

• Cable sizing calculator — full BS 7671 cable selection with correction factors
• Voltage drop calculator — verify compliance with Regulation 525
• Maximum demand calculator — calculate total installation demand with diversity
• Earth fault loop impedance verification
• Prospective fault current calculation
• Adiabatic equation for protective conductor sizing

The BS 7671 reference tables, correction factors, cable data, and protective device characteristics are all stored locally within the app. Calculations execute instantly with no network latency.

The Study Centre downloads course content for offline access. Once a course is downloaded, you can study without any internet connection — video lessons, text content, interactive quizzes, and flashcards all work offline.

This is particularly useful for apprentices who study during commutes, lunch breaks, or quiet periods on site. You do not need to find Wi-Fi to continue your learning. Progress tracking syncs to the cloud when connectivity returns, so your employer dashboard stays up to date.

Mock exams and practice tests also work offline, with results stored locally and synced later. This means you can run through a full AM2 practice exam on the train home without worrying about signal.

Elec-Mate uses a three-tier data persistence strategy to guarantee zero data loss:

• Local save every 10 seconds — all data is written to local device storage every 10 seconds. If your phone dies, you lose at most 10 seconds of work. This happens silently in the background with no impact on app performance.
• Cloud sync every 30 seconds — when a network connection is available, data syncs to the Supabase cloud every 30 seconds. This means your data is backed up and accessible from any device within 30 seconds of entering it.
• Emergency save on exit — if you close the app or navigate away, a beforeunload emergency save captures any unsaved data immediately. This is the final safety net that catches anything between the last auto-save and the moment you close the app.

If you complete a certificate entirely offline, the full dataset is held in local storage until connectivity returns. Once online, the data syncs to the cloud automatically — you do not need to trigger the sync manually. Conflict resolution handles the rare case where the same certificate is edited on two devices simultaneously.

Here is the full breakdown of what works offline and what requires an internet connection:

Works fully offline:

• All 16 certificate types (EICR, EIC, Minor Works, EV, Solar PV, Fire Alarm, Emergency Lighting, PAT)
• All 70+ BS 7671 calculators
• Downloaded training courses, quizzes, and flashcards
• Digital signature capture
• PDF certificate generation
• Test result validation against BS 7671 tables
• Job notes and site photographs (stored locally)

Requires internet connection:

• AI Board Scanner (cloud image processing)
• Voice Test Entry (cloud speech recognition)
• Defect Code AI (cloud AI processing)
• AI Remedial Cost Estimator (cloud pricing data)
• Email/WhatsApp certificate delivery
• Cloud sync and cross-device access
• Initial course downloads

For the AI features, you can capture the data offline (photograph the board, save voice recordings) and process them when connectivity returns. The core certification workflow never depends on an internet connection.

That matters commercially as well as technically. You can keep the job moving in low-signal environments, then feed the completed work into the quoting workflow or the invoice workflow once connectivity returns, without rebuilding the admin from scratch.