High-contrast amber OLED battery gauges for 12V/24V/48V systems featuring voltmeter, dual-bank, and 100A ammeter display options.

Marine OLED battery monitor installed on a sailing catamaran dashboard showing high-contrast visibility in bright daylight conditions.

Technical dimensions for 29mm OLED battery monitor with 6.3mm quick-connect terminals and threaded locking nut for panel mounting.

Supports de montage modulaires 29mm compatibles avec jauges OLED, prises USB et interrupteurs pour tableaux de bord marine et camping-car.

Voltmètre numérique OLED MVA1 pour batterie 12V/24V avec schéma de câblage direct sur bornes positive et négative.

Double voltmètre OLED MVA2 avec schéma de branchement pour monitoring simultané d'une batterie moteur et d'une batterie auxiliaire.

MVA3 OLED Voltmeter and Ammeter wiring diagram with 100A 75mV shunt for negative-side DC load monitoring on boats and RVs.

Ampèremètre OLED MVA4 avec shunt 100A extérieur et schéma de montage pour le suivi précis de la consommation CC (DC).

OLED Battery Monitor (8–60V) – Voltage & Current Display – Waterproof IP66

SKU: MVA1

19.90€; 19.90€
Unit price: per

Display Options: Voltmeter Voltmeter Dual Voltmeter Voltmeter + Ammeter Ammeter

Product variants

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Description
Specification
How to use
FAQ
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OLED Battery Monitors for Boats and 12V / 24V / 48V DC Systems

Keep a clear view of your electrical system with compact OLED battery gauges designed for marine panels, camper vans, RV dashboards and off-grid DC installations. The MVA series gives fast,

BAYWATT — OLED Battery Monitors

BAYWATT
8V–60V DC
12V / 24V / 48V
IP66 Front
See Specs ↓

Keep a clear, reliable view of your electrical system with the BAYWATT MVA series — compact amber OLED gauges built for marine panels, camper vans, RV dashboards and off-grid DC installations. Each unit reads voltage and current in a fast, high-contrast round 29 mm panel-mount format designed to survive salt air, spray and vibration.

Available as a single voltmeter, dual voltmeter, combined voltmeter + ammeter, or dedicated ammeter, the MVA series lets you build the exact monitoring setup your panel needs — from a simple starter-battery check to a full house-bank and load-current dashboard.

Highlights & Callouts

Built for real-world panel use, not just a spec sheet. The MVA series pairs an amber OLED display with marine-grade protection so it stays readable and reliable in daylight, at night and in wet conditions.

Amber OLED — high contrast, wide viewing angle, easy on the eyes at night
0.1V / 0.1A resolution for precise everyday monitoring
IP66 front protection against spray, dust and washdown
Reverse polarity protection built in for safer installs
8V–60V input range covers 12V, 24V and 48V systems in one part

Panel-building tip: The MVA series shares the same 29 mm footprint as our modular USB chargers and rocker switch brackets. Mix and match voltmeters, ammeters, USB ports and switches in a single row for a clean, uniform custom panel.

Why the Amber OLED Display

Daylight & Night Readable High-contrast amber OLED stays sharp in direct sun at the helm and stays comfortable at night — no harsh blue or white glare to disrupt night vision at the wheel.

Low Power Draw OLED pixels only draw current when lit, so the display sips power — safe for permanent connection without meaningfully loading a battery bank.

Compact 29 mm Install Fits the same round cutout used across the industry, with 6.3 mm quick-connect terminals for a fast, tool-light installation.

Choose the Right Model

MVA1 — OLED Voltmeter

Single battery bank voltage
Starter or service battery checks
Simplest, lowest-cost option
No shunt required

MVA2 — Dual OLED Voltmeter

Two battery voltages, one gauge
Start bank + house bank at a glance
Ideal for dual-battery boats
No shunt required

MVA3 — Voltmeter + Ammeter

Voltage and current in one display
Best all-round house-battery monitor
100A shunt included
Shunt installs on the negative side

MVA4 — OLED Ammeter

Dedicated DC load or charge current
Tracks fridges, pumps, inverters, chargers
100A shunt included
Shunt installs on the negative side

Every MVA gauge can be installed on its own for a simple battery check, or combined in a custom multi-gauge dashboard — start battery, house battery, charging current and DC load, each on its own dedicated display.

Why Battery Monitoring Matters

A battery that reads fine at rest can still be too depleted to start an engine or run a fridge overnight — voltage alone only tells part of the story. Pairing a voltmeter with current monitoring on the house bank shows not just how charged a battery is, but how fast it's being drawn down or recharged, so problems show up before they become a dead battery at the dock.

Common Applications

Boat Battery Monitoring: Start and house bank voltage at the helm or nav station.
Marine Switch Panels: Integrated into custom panels alongside switches and USB ports.
RV & Camper Dashboards: Track leisure battery state during off-grid stays.
Off-Grid Battery Boxes: Simple, low-power monitoring for solar and battery enclosures.
DC Load Tracking: Fridges, pumps, inverters, chargers and other always-on circuits.

How to Install Your OLED Battery Monitor

Confirm your system voltage. The MVA series covers 8V to 60V DC, so it's compatible with 12V, 24V and 48V systems — verify your bank voltage before wiring.
Choose the right model for the reading you need. Voltage only (MVA1/MVA2), or voltage plus current (MVA3/MVA4).
Drill the 29 mm mounting hole. Use the included panel cutout template if working from scratch, or match an existing modular panel opening.
Connect the 6.3 mm quick-connect terminals. Wire directly to the positive and negative terminals of the monitored battery bank.
Install the shunt for MVA3/MVA4. Mount the included 100A shunt on the negative side of the circuit — the standard layout for accurate DC current measurement.
Secure with the threaded locking nut. Tighten from behind the panel for a clean, flush front face.
Check polarity before powering up. Reverse polarity protection adds a safety margin, but correct wiring still matters for accurate readings.
Verify the reading against a known reference. Compare against a multimeter on first power-up to confirm correct installation.

Installation note: Always disconnect or isolate the battery bank before making final connections. If you're unsure about shunt placement or wiring for your specific panel, consult a qualified marine electrician.

Built to Handle Marine Conditions

IP66 front protection and a -40°C to +85°C operating range mean the MVA series is built to keep reading accurately through spray, washdown, temperature swings and long-term exposure at the helm.

IP66-rated front face resists water spray and dust
Reverse polarity protection guards against wiring mistakes
Wide -40°C to +85°C operating range for cold starts and hot engine rooms
Quick-connect terminals simplify service and replacement

Complete Your Panel

Pair your OLED gauge with our compatible panel mounts and housings to build a clean, modular dashboard — combine voltmeters, ammeters, USB chargers and rocker switches in the same 29 mm format. See our battery monitor wiring guides for model-specific wiring diagrams.

Frequently Asked Questions

What's the difference between MVA1, MVA2, MVA3 and MVA4?

MVA1 reads one battery's voltage, MVA2 reads two at once, MVA3 adds current monitoring to a voltage reading, and MVA4 is a dedicated current (ammeter) display. MVA3 and MVA4 include a 100A shunt.

Where does the shunt go?

The included shunt for MVA3 and MVA4 installs on the negative side of the circuit, which is the standard layout for accurate DC current measurement.

Can I use this on a 12V, 24V or 48V system?

Yes. The MVA series accepts 8V to 60V DC, so the same gauge works across 12V, 24V and 48V setups without a different model.

Does the display draw much power?

No. OLED pixels only draw current when lit, so power draw stays low enough for permanent connection without meaningfully loading the monitored battery.

Is it fully waterproof?

The front face carries an IP66 rating, protecting against water spray, washdown and dust from the panel side. It is not designed for full submersion.

View Specifications Review Installation

Questions? BAYWATT support can help you pick the right MVA model for your panel — Contact@baywatt.com.

Specification

Technical Specifications

Feature	Specification
System voltage	8V to 60V DC
Supported systems	12V / 24V / 48V DC
Current range	0A to 100A (MVA3 and MVA4)
Display type	Amber OLED, high contrast, wide viewing angle
Resolution	0.1V / 0.1A
Protection	IP66 front side + reverse polarity protection
Mounting hole	29 mm
Terminals	6.3 mm (1/4") quick-connect
Operating temperature	-40°C to +85°C

How to use

How to use :

Discover tips, tricks, and detailed instructions on using our product in our dedicated blog post. Learn about setup, operation, and optimization to get the most out of your purchase.

Link to the blog

FAQ

Frequently Asked Question

Which battery monitor should I choose for a 12V, 24V or 48V boat?

BAYWATT MVA series covers DC systems from 8V to 60V, including 12V, 24V and 48V boat electrical systems. Choose MVA1 for one battery voltage, MVA2 for two battery banks, MVA3 for voltage and current monitoring, or MVA4 for current monitoring only.

Can one dual battery voltmeter monitor both the starter and house batteries?

Yes. The MVA2 dual battery voltmeter displays the voltage of two separate battery banks on one compact OLED gauge. It is ideal for monitoring a boat’s starter battery and house battery, or the main and auxiliary batteries in an RV, camper van or off-grid DC system.

What is the difference between a marine voltmeter and a voltmeter ammeter with shunt?

A marine voltmeter measures battery voltage, while a voltmeter ammeter also measures the current being drawn from or supplied to the electrical system. The MVA1 and MVA2 measure voltage only. The MVA3 combines voltage and current monitoring, while the MVA4 is a dedicated 100A DC ammeter. MVA3 and MVA4 include the required 100A shunt.

Is the BAYWATT OLED battery monitor waterproof for marine use?

The front face is IP66 rated for protection against water spray, washdown and dust, making it suitable for boat dashboards and marine switch panels. The gauge is designed for exposed panel installations but is not rated for complete submersion.

Can this 100A battery monitor be used in a boat, RV, camper van or solar system?

The MVA3 and MVA4 monitor DC current from 0A to 100A and are suitable for tracking onboard loads or charging current from equipment such as fridges, pumps, inverters, battery chargers and solar systems. Their 8V–60V DC range covers most 12V, 24V and 48V marine, RV, camper and off-grid installations.

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