- Solar and energy
- Solar inverter
WARN 702(0)
Growatt WARN 702(0) on APX battery: forced charge needed
Risk level
Medium
Proceed carefully and stop if the check is unclear.
Urgency
High
Quick answer
Growatt warning WARN 702(0) (Forced charge is required) on the APX high-voltage battery system means the battery state of charge (SOC) has dropped below the preset discharge cutoff SOC. Stop discharging the battery, let it run a forced recharge, and call the installer if it will not charge.
Safety first
Stop and check this first
- Growatt warns that discharge under-voltage protection carries a safety risk due to over-discharging, and that residual electricity and heat remain in the APX chassis for 10 to 15 minutes after power-off: never open the junction box or trim covers yourself.
Safe checks you can perform
- Wake the APX LED display and check the red ALM indicator
- Stop discharging the battery and allow recharge power
- Visually inspect the DC switch and external cables
Leave these tasks to a qualified professional
- Do not attempt this professional task: Forced recharge verification and discharge cutoff SOC review
- Do not attempt this professional task: Power cable, fuse and cell under-voltage inspection
What a technician must be able to justify
Technician visit
These are the steps they must carry out and show you. Tick them as they work: if steps are skipped, do not accept a part swap.
These are not instructions for opening or handling the equipment yourself. They are the checks that should support a technical conclusion.
Forced recharge verification and discharge cutoff SOC review
What they doThe installer verifies that the inverter recharges the Growatt APX battery above the preset discharge cutoff SOC and checks the cutoff SOC settings.
They must show youthe battery SOC restored above the cutoff threshold and the alarm log clear of WARN 702(0) and WARN 701(0).
In writingthe preset discharge cutoff SOC value, the post-charge voltage and SOC, and confirmation that the warning cleared.
Power cable, fuse and cell under-voltage inspection
What they doIf the battery will not charge or the red ALM LED is lit, the technician powers off the APX system, waits 10 to 15 minutes wearing protective gloves, and inspects the PM-to-PCS and PM-to-BM power cables, the junction box fuse and cell voltages.
They must show youthe measured module voltages, the condition of the junction box fuse and the ALM indicator extinguished.
In writingthe recorded voltages and which power cable connection or fuse was repaired or replaced.
Before accepting a part or repair
Nothing has been shown yet. Do not accept a part swap based on the code alone.
Follow these steps
Note: Follow the documented order. An error code identifies the affected system, but it does not prove by itself which part has failed.
Wake the APX LED display and check the red ALM indicator
- Who:
- you, standing in front of the Growatt APX battery without removing side trim covers or touching DC cables.
- How:
- if the LED indicators are dark, section 6.4 says you can knock the enclosure below the display to activate the screen; check whether the red ALM light is on at the Power Module or Battery Module.
- Result that matters:
- knowing whether WARN 702(0) is a low-SOC warning alone or accompanied by a red ALM fault.
- If the red ALM light is off and the battery begins charging from solar or grid:
- let the forced charge finish uninterrupted.
- If the red ALM light is on:
- Growatt warns of a safety risk from over-discharging; stop discharging the battery and contact your installer.
- Evidence to keep:
- a photo of the APX LED panel and a screenshot of WARN 702(0) with the current SOC percentage.
Evidence: User Manual APX 5.0~30.0P-S0-US High Voltage Battery System (GR-UM-340-A-00)
Stop discharging the battery and allow recharge power
- Who:
- you, using household appliance switches and checking the monitoring app.
- How:
- switch off heavy backup loads and confirm in the app that the inverter is powered on with grid or daytime PV available to supply the forced charge to the APX battery.
- Result that matters:
- allowing the battery SOC to climb back above the preset discharge cutoff SOC.
- If the SOC rises and WARN 702(0) clears once above the cutoff threshold:
- monitor it over the next cycle.
- If the battery refuses to charge even with grid or sunshine available:
- contact the installer promptly.
- Evidence to keep:
- app screenshots showing the SOC percentage trend and charging power in watts.
Evidence: User Manual APX 5.0~30.0P-S0-US High Voltage Battery System (GR-UM-340-A-00)
Visually inspect the DC switch and external cables
- Who:
- you, carrying out the external visual check described in section 6.7 of the APX manual.
- How:
- look from outside to see whether the APX DC switch is in the ON position and check for any externally visible damage or discoloration on the DC switch and cables without touching them.
- Result that matters:
- spotting an open switch or damaged cable that prevents the forced charge from flowing.
- If you see any visible damage or discoloration on the DC switch or cables:
- do not touch the unit and contact the installer as Growatt instructs.
- If the switch and cables look intact externally but WARN 702(0) stays active:
- book a technician to inspect the power and PCS link.
- Evidence to keep:
- an external photo of the APX DC switch position and outer cable runs.
Evidence: User Manual APX 5.0~30.0P-S0-US High Voltage Battery System (GR-UM-340-A-00)
Still not solved
If the error persists, stop here. See what the technician must do and show you.
Where this code applies
A code is meaningful only inside the right product and version context.
Primary scope
- System
- Solar and energy
- Brand
- Growatt
- Product type
- Solar inverter
Known code variants
- batería Growatt APX carga forzada requerida
- Forced charge is required Growatt
- Forced charge is required Growatt APX
- Growatt APX WARN 702(0)
- Growatt battery SOC below discharge cutoff
- Growatt WARN 701(0) WARN 702(0)
- Growatt WARN 702(0)
- WARN 701(0) WARN 702(0) Growatt
- WARN 702 Growatt APX
What it means
In the Growatt APX 5.0~30.0P-S0-US High Voltage Battery System user manual (edition GR-UM-340-A-00, section 6.6), WARN 702(0) 'Forced charge is required' is listed for both the Power Module (PM, APX 55042-P0-US) and the Battery Module (BM, APX 5.0P-B1-US). Growatt explains that the battery SOC is lower than the preset discharge cutoff SOC (after WARN 701(0) stops discharging at that cutoff), so a forced charge is required. If a single cell also drops below the under-voltage threshold, the red ALM LED lights up due to over-discharging risk. The code alone never proves a module is faulty.
Warnings and stop conditions
- Highsource verified
Growatt warns that discharge under-voltage protection carries a safety risk due to over-discharging, and that residual electricity and heat remain in the APX chassis for 10 to 15 minutes after power-off: never open the junction box or trim covers yourself.
Evidence: User Manual APX 5.0~30.0P-S0-US High Voltage Battery System (GR-UM-340-A-00)
Symptoms and causes
Probable causes · in order
- Battery SOC below the preset discharge cutoff SOCCommon
Growatt's Power Module and Battery Module fault tables state that WARN 702(0) triggers when the battery state of charge falls below the preset discharge cutoff level.
Evidence: User Manual APX 5.0~30.0P-S0-US High Voltage Battery System (GR-UM-340-A-00)
- Extended standby or backup draw without solar or grid chargingPossible
Once the battery hits the discharge cutoff (WARN 701(0)), continued self-consumption without PV or grid power pulls the SOC lower until forced charging is demanded.
Evidence: User Manual APX 5.0~30.0P-S0-US High Voltage Battery System (GR-UM-340-A-00)
- Single cell voltage below the discharge under-voltage thresholdPossible
In section 6.5, Growatt notes that if any single cell drops below the under-voltage protection threshold, the red ALM light turns on and the battery must be recharged.
Evidence: User Manual APX 5.0~30.0P-S0-US High Voltage Battery System (GR-UM-340-A-00)
Virtual technician
Does WARN 702(0) still appear after these checks?
Answer a few questions to narrow down the likely cause and the safest next action. Guidance only - it never replaces a professional.
Sources and technical references
- 1
User Manual APX 5.0~30.0P-S0-US High Voltage Battery System (GR-UM-340-A-00)
Growatt USA, Inc. · 2024 · manual
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