Universal Load Controller

Universal Load Controller — Professional Battery Testing

Control your Atorch DL24 / DL24P electronic load from your iPhone or iPad for precise battery capacity testing, logging and analysis.

BEFORE YOU BUY — COMPATIBILITY

iOS cannot use classic Bluetooth SPP, which is what the stock DL24/DL24P Bluetooth module uses. Please check the following list first.

WORKS FULLY — DL24 firmware v5.1 (+ BLE serial adapter)
• Direct setpoints: discharge current and cutoff voltage sent from the app
• Start / stop of the load from the app
• Read-back of the applied settings
• Automated multi-phase test cycles (discharge, rest, ramp)
• Live values, charts, capacity/energy logging, CSV and PDF export

WORKS WITH LIMITS — DL24 firmware v1.1 (legacy)
• Firmware v1.1 accepts button emulation only: SETUP, OK/On-Off, +/-
• It does NOT accept direct commands for exact current or cutoff values
• Therefore automated app cycles are blocked on v1.1 by design — the app tells you instead of applying a wrong setpoint to your cell
• Recommended use: set current and cutoff manually on the DL24, then use the app in Manual mode for live values, timing, logging, charts and export
• Select "Firmware v1.1" in Settings, Protocol, so the app uses the matching command set

DOES NOT WORK
• Stock classic-Bluetooth (SPP) module: iOS does not allow regular apps to use SPP. A BLE serial module or BLE-to-serial bridge is required.
• USB / HID connection to the load (iOS has no equivalent of the vendor PC app)
• CR / CP / CV modes: the Atorch protocol exposes only constant current (CC). Other modes can neither be read nor set — by any app, on any firmware.
• iOS 16 or older — this app requires iOS 17.0 or newer.

REQUIRED HARDWARE FOR A REAL CONNECTION
• Atorch DL24 / DL24P electronic load, plus one of:
- a BLE serial module (HM-10 or compatible, service FFE0 / characteristic FFE1) in place of the classic Bluetooth module, or
- an external BLE-to-serial bridge exposing FFE0/FFE1 or the Nordic UART Service (6E400001-B5A3-F393-E0A9-E50E24DCCA9E)
• Related Atorch meters advertising as DL24P, DL24_BLE, DL24, AT24, UD24, UD18 or DT24 are detected during the scan, but only the DL24 load family is supported for control.

NO HARDWARE? Simulation Mode runs the complete app with a realistic simulated discharge, so you can evaluate every screen before buying an adapter.

FEATURES

BATTERY TESTING
• Constant-current discharge with adjustable cutoff voltage
• Real-time voltage, current, power and temperature
• Capacity (mAh) and energy (Wh) measurement
• Time and capacity limits

LIVE DATA
• Real-time discharge curves with zoom and pan
• Voltage, current and capacity plots
• Live Activity on the Lock Screen, Always-On Display and Dynamic Island
• Home Screen widgets for the running test
• Background Bluetooth so a test keeps logging

TEST CYCLES (firmware v5.1)
• Presets for LiPo, Li-Ion, LiFePO4 and NiMH
• Custom cycles with discharge, rest and ramp phases

EXPORT
• CSV export of the full measurement log
• PDF test report with the run summary
• Share sheet support for both

Perfect for battery capacity verification, cell matching and sorting, quality control, hobby electronics and lab use.

SAFETY: You are testing real cells at real currents. Always verify current and cutoff values on the device itself, use protected cells or a current-limited bench setup, keep physical access to the load's stop control, and never leave a running test unattended.

Universal Load Controller is an independent app. It is not affiliated with, endorsed by, or supported by Atorch.