User Manual

User Manual: Download Manual (6.5mb PDF)

Simplified 4 Cell Assembly

Ultra simple view of a complete 4 cell battery assembly.
– Click for full resolution.

Bluetooth Mobile Apps

iPhone App: Overkill Solar Mobile App (Apple App Store)

Android App: Overkill Solar Mobile App (Google Play Store)

To sideload the APK on your Android device, Click here.

Here you will also find the version notes for every update of the mobile app. Note: Regardless of how you load the app, it will silently update when we publish bug fixes, assuming the device has an internet connection. We do not collect any data of any kind from the app, unless you manually send a help request. Even then, no personal data is sent, only the BMS’s technical data.

Desktop App with password reset tool:

Overkill-Solar-bms-tools for Windows

(Download latest release package, unzip and run)

(JBD Chinese version) Old Android App:


Download and install the APK, Allow 3rd party apps to install.

(JBD Chinese version) Desktop App:

JBDTools V2.9-20210524

(unzip and run)

Backup parameter files for desktop apps:

Hacker Tools

Communication Protocol Documentation

Arduino library: Version 2 (read/write)

Other Instruction Sheets

BMS configuration for other cell counts PDF

Detailed Instructions, 8 cell 24v battery with BMS. PDF

4 cell 12v Wiring Diagram & settings PDF

8 cell 24v Wiring Diagram & settings PDF

16 cell 48v Wiring diagram & settings PDF




Safety Data Sheets

Tesla Lithium-ion Battery Emergency Response Guide

Overkill Solar Lithium Iron Phosphate Battery SDS

Useful Forums:

iRV2 Forums


DIY Solar Power with Will Prowse (youtube channel)

About Cell Balancing

Overkill Solar YouTube Channel:

Salvaged Tesla Batteries for Off-Grid Power?

How much battery power to make a pot of coffee?

Read BMS parameters on an iPhone

Do bigger wires make a difference?

A tool to solder 8ga BMS wires

Tech Support, etc:

For troubleshooting help , please include a screenshot and clear photos of your battery. 9 out of 10 problems are an incorrect setting or an incorrect connection.