Article: How to Configure the Victron MultiPlus-II for Lithium Batteries
How to Configure the Victron MultiPlus-II for Lithium Batteries
The Victron MultiPlus-II is one of the most capable inverter/chargers you can install — but it ships configured for lead-acid batteries. If you've paired it with a LiFePO4 bank and left the settings at their defaults, you're running the wrong charge profile. Over time, that means an underperforming bank at best, and accelerated degradation at worst.
Configuring the MultiPlus-II for lithium takes less than an hour, and it makes a real difference. Here's what to change and how to do it.
Why Lead-Acid Defaults Don't Work for Lithium
AGM and LiFePO4 batteries have different voltage profiles and charging behavior. The key differences that matter for configuration:
Float voltage: AGM floats at around 13.5–13.8V (12V system). At float, the charger maintains that voltage continuously — which is fine for AGM. LiFePO4 doesn't need or benefit from float charging. Holding a fully charged LiFePO4 cell at a constant voltage causes micro-cycling, heat, and unnecessary wear. LiFePO4 should float at 13.2–13.5V — or ideally, the charger should stop charging altogether once the bank is full.
Absorption time: AGM batteries need a long absorption phase — sometimes 2–4 hours — to fully charge the final portion of capacity. LiFePO4 has a much flatter charge curve and finishes bulk charge very close to full capacity. A long absorption phase at high voltage on a lithium bank adds heat and stress without adding meaningful capacity.
Temperature sensitivity: Most modern LiFePO4 batteries have built-in temperature sensing via the BMS and will cut charging at low or high temperature extremes. The MultiPlus-II's default settings don't account for this — the BMS is the real protection, but your charger settings should still be sensible.
What You Need to Configure the MultiPlus-II
There are two ways to access the MultiPlus-II settings:
VEConfigure + MK3-USB Interface: VEConfigure is Victron's PC configuration software (Windows). It connects to the MultiPlus-II via an MK3-USB interface cable, which plugs into the RJ45 VE.Bus port on the unit. This is the traditional method and gives you the most granular control over all settings. Required hardware: an MK3-USB interface cable.
Via Cerbo GX / VRM Remote Configuration: If your system includes a Cerbo GX connected to the MultiPlus-II via VE.Bus, you can push configuration changes through the GX device — either locally through the GX Touch display, or remotely through the VRM portal. This is convenient once the system is installed and doesn't require a laptop near the unit.
Both methods give you access to the same settings. For an initial lithium configuration, VEConfigure is the most straightforward.
The Settings to Change
Charge Voltages
These are the most important parameters:
| Setting | AGM Default (12V) | LiFePO4 Target (12V) |
|---|---|---|
| Absorption voltage | 14.4V | 14.2–14.4V (per manufacturer) |
| Float voltage | 13.8V | 13.2–13.5V |
| Storage voltage | 13.2V | 13.2V (or disable storage mode) |
| Low battery shutdown | 10.8V | 11.5–12.0V |
Absorption voltage: Most LiFePO4 manufacturers spec 14.2–14.4V at the 12V level. Check your battery's documentation — this is the maximum charge voltage, and exceeding it is what causes real damage. Use the lower end of the manufacturer's range when in doubt.
Float voltage: This is where most unconfigured systems cause the most wear. Drop float to 13.2–13.5V. At this level, the charger will maintain the battery if it discharges slightly while at rest, but won't drive continuous current through a full bank.
Low battery shutdown: AGM's default (10.8V) is too low for LiFePO4. Raise this to 11.5–12.0V to add a charger-side low-voltage floor. The BMS will disconnect before this, but having a backup cutoff in the charger settings is good practice.
Absorption Time
In VEConfigure, set the adaptive absorption time to a fixed value rather than adaptive for lithium. A fixed absorption time of 1 hour is appropriate for most installations — LiFePO4 doesn't need the extended absorption that AGM requires, and a short absorption window prevents the charger from holding high voltage longer than necessary.
Charge Current
Set the charge current limit to match your battery bank's maximum continuous charge rate. Most LiFePO4 batteries specify a maximum charge current of 0.5C (50% of capacity in amps) — so a 200Ah bank accepts up to 100A of charge current. If your MultiPlus-II's charge output exceeds this, cap the charge current in configuration to stay within the battery's spec.
DVCC: The Better Approach for BMS-Managed Systems
If your system includes a Cerbo GX and a BMS that communicates digitally (via CAN bus or VE.Direct), you can enable DVCC — Distributed Voltage and Current Control.
With DVCC active, the BMS takes over real-time control of charge parameters. Rather than using the static voltage and current values configured in the MultiPlus-II, the GX device receives live charge limits from the BMS — Charge Voltage Limit (CVL) and Charge Current Limit (CCL) — and passes those to the MultiPlus-II dynamically.
This means the BMS manages charging based on actual cell voltages and temperature in real time, rather than relying on fixed profile values. The MultiPlus-II still enforces its configured settings as a ceiling, but the BMS can throttle current or voltage below those limits as needed.
DVCC is the cleanest approach for integrated Victron + compatible BMS systems. If your BMS doesn't support digital communication, static VEConfigure settings are your fallback.
To enable DVCC: in the Cerbo GX menu, go to Settings → System Setup → DVCC and enable it. The GX device will detect whether a compatible BMS is present and activate BMS control automatically.
Common Mistakes
Leaving float at AGM levels. The most common error. If float is set to 13.8V and the bank is full, the charger is pushing constant voltage into cells that don't want it. Drop float to 13.2–13.5V.
Using the default adaptive absorption time. Adaptive absorption on the AGM profile can run for several hours. On a lithium bank, this holds the battery at absorption voltage far longer than needed. Switch to fixed 1-hour absorption.
Not checking the battery manufacturer's voltage specs. Every LiFePO4 product has slightly different voltage recommendations. The values above are common, but your manufacturer's spec sheet is the authority. A battery specced for 14.6V absorption can safely use 14.6V — one specced for 14.2V cannot safely run at 14.6V.
Assuming the BMS is the only protection you need. The BMS is the last line of defense — it disconnects the battery when limits are exceeded. Configuring the charger correctly means the BMS rarely (if ever) has to intervene. A BMS that disconnects frequently is a sign that upstream settings need adjustment.
Browse our inverter/charger and lithium battery collections at Blue Marine. If you want help dialing in your MultiPlus-II configuration for a specific battery and use case, schedule a free consultation — our ABYC-certified team configures these systems regularly.
Related reading:
Alternator Charging with Lithium Batteries: What You Need to Know
How to Wire Lithium Batteries in Parallel (Safely)
The Complete 2026 Boating Guide: New Codes and Standards
