Hi, I’m looking to replace my Magnum Energy ME-3112 for a couple of reasons. First, it is no longer supported. Second, I now have solar and would like to prioritize solar over grid energy and save a few $$. Third is for remote monitoring and configuration. My question is this. Since I’m only using one 120v input and and one 120v output on my ME-3112 so will this be a pretty simple plug and play replacement? There are limited appliances and sockets (load), my house battery bank is 6 x 100ah LiFePO4 batteries. Shore power comes in at 240v 50 amps but is split on the way in into 2 x 120v. Looking forward to some feedback on this. Thanks, Brad
Really easy to do that with Victron equipment.
points to consider:
upgrade to 24V house if power is 3kW or over - better efficiency, lower cost of inverter.
Add a smart shunt for more precise house bank monitoring.
Lots of examples about.
Thanks for the info.
The batteries are directly wired to the 12v side of the house so switching to 24v would complicate the project.
Is there anything I need to watch out for in the current configuration that would compromise the replacement with the multi plus? My 240 volt comes in and then gets split. I believe that the 120 volts will still be sent to the inverter however I’m not sure if the inverter is passing the 120 volt through when on shore power or if my rotary switch is just switching over those circuits. I got to believe that it’s passing through but not positive.
Just an update. I did further detailed research using my ChatGPT account and wanted to see what everyone thought. Under the objective of maximizing solar and prioritizing batteries for loads here’s what ChatGPT had to say (clips from the last couple of responses):
Short version: I’m highly confident about the Victron behavior (≈90–95%), and mildly confident about the exact quirks you saw on the Renogy Rover (≈70–80%) because that controller’s float/re-bulk logic is… let’s call it “interpretive dance.”
Why I’m confident on Victron
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Charge stages & tail current are explicit. SmartSolar uses standard Bulk → Absorption → Float with configurable tail current and timers. When it’s in float, it will reduce battery charging current, but DVCC/ESS still let PV serve live loads. That’s in Victron’s MPPT manual and configuration docs. Victron Energy+2Victron Energy+2
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DVCC centralizes the rules. With a Cerbo GX, DVCC turns the GX into the traffic cop for charge voltage/current limits system-wide. So the MPPT doesn’t go rogue; it follows the GX, and in ESS the MPPT even follows the charge curve set in VEConfigure rather than its own local setpoints. Victron Energy+1
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ESS “solar first” is a GX/Multi setting. Priority comes from ESS, not from the MPPT. ESS uses PV first, then battery, and only pulls grid/generator when the SOC floor or power limits demand it. Victron Energy+1
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BMV-712 relay/SOC control is documented. Using the BMV relay to clamp DVCC charge current at 90% SOC and resume at 70% is straight from the BMV feature set. Victron Energy+2Victron Energy+2
Why your Renogy experience felt different
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Renogy Rover controllers use a 4-stage scheme (Bulk/Boost/Float/Equalize). In float, they’ll often sit there and not re-enter “boost” until the battery drops below a re-bulk threshold or a timer/event kicks them back. That can look like “throttling solar unless in bulk,” because PV won’t ramp until voltage dips enough to trigger a new stage. Lowes+1
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Victron’s setup with DVCC/ESS still lets PV cover loads while in float; you’ll mainly see the battery charge taper, not PV-to-loads. That difference in coordination is the whole point of the GX + DVCC stack.
Victron System Configuration + Wiring Plan (Solar‑First, 70–90% SOC)
1. System Overview
Components:
- Battery bank: 6 × 100 Ah LiFePO₄ (12 V nominal, 600 Ah total)
- SmartSolar MPPT 150/70
- MultiPlus II 12/3000/120‑50
- BMV‑712 Smart (one relay used for alternator charge control via Cyrix Li‑CT)
- Cerbo GX Mk2
- Shore/generator AC input
- Alternator charge path through Victron Cyrix Li‑CT relay
Goal: Prioritize solar, maintain 70–90 % SOC, and fall back to shore/gen below 20 %.
2. Wiring Layout
DC Power Paths
[PV Array] → [SmartSolar MPPT 150/70] → [Battery Bank (+/–)]
│
├─ [BMV‑712 Shunt → BMV Display]
│ │
│ ├─ VE.Direct → Cerbo GX (VE.Direct Port #1)
│ └─ Relay 1 → Cerbo Digital Input (for charge‑limit trigger)
│
├─ [MultiPlus II DC+/–] → Battery Bank
│ └─ VE.Bus → Cerbo GX (VE.Bus Port)
│
└─ [SmartSolar MPPT VE.Direct] → Cerbo GX (VE.Direct Port #2)
AC Paths
[Shore/Generator AC Input] → [MultiPlus II AC Input]
[MultiPlus II AC Output] → [AC Distribution Panel] → [House Loads]
Alternator Integration
[Main Engines → Alternators] → [Cyrix Li‑CT Relay] → [Battery Bank]
↑
│
└─ Control signal from BMV‑712 Relay 2
3. Communication Cabling
| Device | Port on Cerbo GX Mk2 | Purpose |
|---|---|---|
| BMV‑712 | VE.Direct #1 | SOC / relay status for DVCC logic |
| MPPT 150/70 | VE.Direct #2 (or VE.Can if that model) | PV data + DVCC control |
| MultiPlus II | VE.Bus | ESS coordination |
| Cyrix Li‑CT | BMV relay output | Alternator charge enable/disable |
4. Configuration Screens / Settings
A. SmartSolar MPPT ( VictronConnect )
| Setting | Value | Purpose |
|---|---|---|
| Absorption Voltage | 14.4 V | Per battery spec |
| Float Voltage | 13.4–13.5 V | Lower float for LiFePO₄ longevity |
| Absorption Time | 60 min | Enough to reach full charge without overstay |
| Tail Current | 4 % (24 A) | Exit absorb threshold |
| Re‑bulk Voltage | 13.2 V | Restart charging promptly |
### B. Cerbo GX → DVCC Screen
- Enable DVCC = ON
- Shared Voltage Sense = ON
- Shared Current Sense = ON
- Limit Charge Voltage = ON
- Limit Charge Current = 70 A (normal), 0–5 A (when BMV relay active ≥ 90 %)
### C. ESS Configuration ( Venus OS )
| Setting | Recommended Value |
|---|---|
| Mode | Optimize (with BatteryLife) |
| Minimum SOC | 20 % |
| Grid Setpoint | 0 W (solar first) |
| BatteryLife | Enabled |
| Use Solar Power First | Yes |
### D. BMV‑712 Settings
| Parameter | Value | Function |
|---|---|---|
| Relay 1 Clear (ON) | 90 % SOC | Signal to limit charge current |
| Relay 1 Set (OFF) | 70 % SOC | Resume normal charging |
| Charged Voltage | 14.4 V | SOC calibration point |
| Tail Current | 24 A | Matches DVCC tail |
| Charged Detection Time | 3 min | Prevent false full detection |
| Relay 2 | Controls Cyrix Li‑CT for alternator charging |
5. Operating Logic Summary
- SOC < 70 %: BMV relay open → DVCC charge limit = 70 A → MPPT charges fully (bulk mode).
- 70–90 %: Normal operation → MPPT tops battery and feeds loads.
- ≥ 90 %: BMV relay closed → Cerbo limits charge current to 0–5 A → PV only feeds loads.
- Night: Battery discharges → MultiPlus powers loads until SOC 20 %.
- SOC ≤ 20 %: ESS triggers shore/gen assist → recharges to ≥ 70 %.
- Alternator charging: BMV relay 2 engages Cyrix Li‑CT only when battery SOC < 90 % and alternator voltage available.
6. Safety & Fusing
- Use class‑T main fuse (> 300 A) at battery positive.
- Individual fuses for MPPT and MultiPlus circuits sized for each max amp rating.
- Common negative through BMV shunt.
- Proper busbars and isolation switches for maintenance.
Expected Behavior
- Daylight PV (≤ 500–700 W) supplies loads first and charges battery to ≈ 90 %.
- At night battery runs loads until 20 % SOC, then shore/gen supports.
- Alternator charging is managed automatically when engines run.
This configuration keeps LiFePO₄ cells between 70–90 % for daily cycling, uses solar first, and prevents grid draw until the bank reaches ≈ 20 % SOC.