RV-BMS app icon
Bluetooth BMS · iPhone · iPad · CarPlay · Apple Watch

Inside your battery
Every cell, live

RV-BMS reads the Bluetooth BMS of your lithium battery and shows what is really going on: charge, power, every cell, temperatures and alarms. On iPhone, in the car and on your wrist.

Available on the App Store View on GitHub
DIRECT BLUETOOTH Talks to your battery's BMS, no gateway or extra hardware
CARPLAY + VOICE Charge, power and cells on the car's screen, read aloud while you drive
LIVE ACTIVITY & WIDGETS Your battery on the Lock Screen, in the Dynamic Island and on the Home Screen
ON YOUR WRIST An Apple Watch app with watch face complications
30-DAY HISTORY Charts, charged and discharged energy, CSV export
PRIVATE BY DESIGN No account, no cloud, no tracking
78%State of charge
13.05 VBattery
−253 WPower
4h 14mTime to empty
USER FEATURES

Your battery, at a glance.

The values that matter in an RV, a van or a boat: how much energy is left, where it is going, and whether every cell is healthy.

78%State of charge
13.05 VBattery voltage
−19.3 ACurrent
5 mVCell difference
100%State of health
DASHBOARD

Everything on one screen

State of charge, voltage, current, power, remaining Ah and time to empty or to full, updated every 2 seconds.

CELLS

Every cell voltage

Each cell with lowest and highest highlighted, the cell difference, and which cells are balancing.

HEALTH

Beyond the percentage

State of health, cycles, temperatures, whether the BMS allows charging and discharging, and its alarms.

BACKGROUND

Always up to date

Keeps reading while the app is in the background and reconnects on its own when the battery is back in range.

VOICE

Spoken status in 5 languages

On CarPlay, hear charge, power and alarms in English, Italian, French, German or Spanish.

DEMO MODE

Try it with no battery

A simulated battery shows every screen, including CarPlay, Apple Watch, Live Activity and widgets.

RV-BMS dashboard with state of charge, voltage, current, power, cells and details
iPhone & iPad

The whole battery.
One screen.

A gauge for the charge, big numbers for voltage, current and power, a bar for every cell and all the BMS details underneath.

Time left. Time to empty while discharging, time to full while charging.
Cell balance. Lowest and highest cell highlighted, balancing cells marked.
BMS status. Alarms, charge and discharge cut-offs shown as soon as they happen.
Apple CarPlay

Your battery.
Without taking your eyes off the road.

A live status row and three pages, Overview, Cells and Health. Open one and RV-BMS reads the values aloud through the car's audio.

Glance at the status. Battery, charge, power and connection always at the top.
Hear the values. Open a page to hear it, open it again to repeat.
CarPlay widgets. Keep the battery on the CarPlay dashboard.
English (US)ItalianoFrançaisDeutschEspañol
RV-BMS on Apple CarPlay with battery status and the Overview, Cells and Health pages

Each page shows its values on the car's screen:

RV-BMS CarPlay Overview page
Overview
RV-BMS CarPlay Cells page
Cells
RV-BMS CarPlay Health page
Health
RV-BMS Live Activity on the iPhone Lock Screen
LIVE ACTIVITY & WIDGETS

Start it once.
Watch it update itself.

Turn on the Live Activity from the menu and your battery stays on the Lock Screen and in the Dynamic Island, updated in the background, without unlocking your phone.

Lock Screen and Dynamic Island. Charge, power, voltage, current and time left.
Home Screen widgets. Small and medium, with charge, power and time left.
Lock Screen and CarPlay widgets. Circular, rectangular and inline.
30-DAY HISTORY

See where the energy went.

RV-BMS saves a reading every minute, also in the background. Charts for 1 hour up to 30 days, energy charged and discharged, peak power, and CSV export.

RV-BMS history chart of state of charge over 24 hours

Charge

How the state of charge moved through the day, with the charge range for the period.

RV-BMS history chart of power, charging in green and discharging in orange

Power

Charging in green, discharging in orange, with Wh charged and discharged.

RV-BMS history chart of battery temperature

Temperature

Plus voltage, current and cell difference, one tap away.

APPLE WATCH

On your wrist.

A dedicated RV-BMS app for Apple Watch, for a glance while you're outside the van.

RV-BMS Apple Watch app with the charge ring, power, voltage and current
Charge ring and power
RV-BMS Apple Watch details: remaining Ah, time left, temperature
Remaining and time left
RV-BMS Apple Watch details: cell difference, alarms and status
Cells, alarms, status
WATCH APP
Live while it's open

Charge ring, power, voltage, current and time left, updated every couple of seconds from your iPhone.

COMPLICATIONS
Charge on your watch face

Circular, rectangular, inline and corner complications, so the charge level is always one glance away.

RV-BMS Pro

Try it all free.
Own it once.

The iPhone app with your battery, its history and export is free. CarPlay, Apple Watch, Live Activity and widgets are free in demo mode. RV-BMS Pro shows your real battery on all of them, with a single one-time purchase.

One purchase. No subscription, no recurring fees.
Try before you buy. Demo mode runs every Pro feature with a simulated battery.
Unlocked everywhere. CarPlay, Apple Watch, Live Activity and widgets.
RV-BMS Pro purchase screen
Compatible batteries

Supported battery management systems.

Your battery needs a Bluetooth BMS. "Tested" means verified with RV-BMS on a real battery; "beta" protocols are checked against data recorded from real batteries and are waiting for field confirmation.

BMS FAMILY
FOUND IN
DISPLAYED VALUES
Redodo BMSTESTEDPowerQueen, Redodo, LiTime, Starry SeaCharge, voltage, current, power, remaining and full capacity, health, cycles, every cell, temperatures, balancing, alarms.
JK (Jikong)BETADIY and RV LiFePO4 packsCharge, voltage, current, capacity, health, cycles, every cell, up to six temperatures, charge and discharge status, alarms.
JBD (Xiaoxiang)BETAMany drop-in LiFePO4 batteriesCharge, voltage, current, capacity, cycles, every cell, temperatures, balancing, charge and discharge status, alarms.
DalyBETADaly Bluetooth BMS modulesCharge, voltage, current, remaining capacity, cycles, every cell, temperatures, charge and discharge status, alarms.
Simple setup

No keys.
No accounts.

RV-BMS finds compatible batteries on its own and remembers the one you pick.

1
Close the manufacturer's appMost BMS accept only one Bluetooth connection at a time.
2
Open RV-BMS near the batteryCompatible batteries appear under Nearby batteries.
3
Pick yoursRV-BMS connects, and reconnects on its own next time.
4
No battery at hand?Tap "Try demo mode" to explore every screen.
RV-BMS on iPad
TECHNICAL FOUNDATION

Direct Bluetooth. Local processing.

The details behind the experience. RV-BMS talks to the BMS directly and keeps everything on your device.

BLUETOOTH LE
Read-only GATT connection

RV-BMS connects to the battery you select and only requests status data. It never sends commands that change the BMS settings.

BACKGROUND
Stays connected

Background Bluetooth and state restoration keep the Live Activity, widgets, Apple Watch and history up to date, and reconnect when the battery is back in range.

VERIFIED PROTOCOLS
Tested against recorded data

Every protocol is checked against frames recorded from real batteries by the open-source aiobmsble project, field by field.

PRIVACY
No server at all

No account, no analytics, no tracking. Readings and history are decoded and stored only on your iPhone.

RV-BMS

Know what your battery is doing.
Even while you're driving.

Bluetooth BMS monitoring for iPhone, iPad, Apple CarPlay and Apple Watch, built for life on the road.

Available on the App Store GitHub Support