Victron MPPT Charge Controller Open-loop Configuration Procedure

During normal operation, the MPPT charge characteristics are governed by the Victron GX device in a closed-loop configuration based on data and charge requests provided by the connected Discover Lithium battery.

When closed-loop communication has failed, the MPPT needs to be reset and reconfigured to use open-loop communication. Simply cycling the power does not reset the charger.
To remove the charger from a closed-loop system and use it in a system without a BMS:

Chargers with LCD display: From the setup menu, change the BMS setting from Y to N.
Other chargers: Using Victron Connect, reset the charger to factory defaults.
Reconfigure the charger with the recommended open-loop (voltage-based) settings for the Victron MPPT in the table below.

The Victron Connect Bluetooth App is used to configure, monitor, and diagnose Victron MPPT Charge Controller products equipped with Bluetooth.

Victron Connect Bluetooth App

Victron Connect Bluetooth App > Device List > Victron MPPT > Settings > Battery

MPPT Battery Settings Menu	AES RACKMOUNT 48-48-5120 / 48-48-5120-H	HELIOS ESS 52-48-16000
Battery voltage	48 V	48 V
Max charge current⁽¹⁾	Number of batteries x 95 A	Number of batteries x 200 A
Charger enabled	Enabled	Enabled
Battery preset	User Defined	User Defined
Expert mode	Disabled	Disabled
Absorption voltage	55.2 V	55.2 V
Float voltage	53.6 V	53.6 V
Equalization voltage	55.2 V	55.2 V
Automatic equalization	Disabled	Disabled
Temperature compensation	Disabled	Disabled
Low temperature cut-off	< 4°C (39.2°F)	< 4°C (39.2°F)
Maximum absorption time⁽²⁾	1.0 < 3.0 Hr	1.0 < 3.0 Hr

⁽¹⁾ May be set to a lower value if necessitated by charger controller size.

⁽²⁾ When editing battery presets, set the duration of the absorption period, which occurs after the bulk charge interval. The recommended minimum is 1.0 hour. Multiple batteries may require a longer time to achieve a smooth completion of charge.