Thermal Runaway Detector

Thermal Runaway Overview

I created the following device after I saw a problem where expensive battery strings were being destroyed from thermal runaway. Nothing came of the project but it was an interesting exercise in identifying a problem and creating a fix for it. The device has four temperature sensor channels and four interrupt relays. Temperature set points can be set through a serial interface with the device. Alarms can be set for various temperature levels and a trip point can be set when a critical high temperature is reached. When the trip point is reached, one or more of the relays will change state. These relays are designed to interface with an under voltage release (UVR) breaker. The relay interrupts the control signal to the breaker causing it to trip open and physically isolate the battery string from the charger. There are two small signal relays to provide simple normally open (NO) dry contacts for alarm monitoring. The following is a quick instruction manual I made for the device:

Thermal Runaway Documentation Thermal Runaway Repository

Thermal Runaway Pictures

Thermal Runaway PCBS Top View
Thermal Runaway PCBS Top View
Thermal Runaway PCBS Bottom View
Thermal Runaway PCBS Bottom View
Thermal Runaway Printed Parts
Thermal Runaway Printed Parts
Thermal Runaway Assembled - Top Off
Thermal Runaway Assembled - Top Off
Thermal Runaway Fully Assembled
Thermal Runaway Fully Assembled

Thermal Runaway Schematics

The Thermal Runaway PCBs were designed using Express PCB.

Thermal Runaway PCB Source
Thermal Runaway Schematic - Main PCB
Thermal Runaway Schematic - Main PCB
Thermal Runaway Schematic - IO
Thermal Runaway Schematic - IO
Thermal Runaway Schematic - HMI
Thermal Runaway Schematic - HMI

Thermal Runaway PCB Design

Main PCB Top Layer
Main PCB Top Layer
Main PCB Bottom Layer
Main PCB Bottom Layer
Main PCB Top, Bottom and Silkscreen Layer
Main PCB Top, Bottom and Silkscreen Layer
IO PCB Top Layer
IO PCB Top Layer
IO PCB Bottom Layer
IO PCB Bottom Layer
IO PCB Top, Bottom and Silkscreen Layer
IO PCB Top, Bottom and Silkscreen Layer
HMI PCB Top Layer
HMI PCB Top Layer
HMI PCB Bottom Layer
HMI PCB Bottom Layer
HMI PCB Top, Bottom and Silkscreen Layer
HMI PCB Top, Bottom and Silkscreen Layer
Temp Sensor PCB Top Layer
Temp Sensor PCB Top Layer
Temp Sensor PCB Bottom Layer
Temp Sensor PCB Bottom Layer
Temp Sensor PCB Top, Bottom and Silkscreen Layer
Temp Sensor PCB Top, Bottom and Silkscreen Layer

Thermal Runaway CAD Design

The Thermal Runaway Enclosure was designed in Free CAD.

Thermal Runaway CAD Source
Thermal Runaway Enclosure
Thermal Runaway Enclosure

Thermal Runaway Firmware Source Code

The source code for this project was developed using Atmel Studios.

Thermal Runaway Firmware Source