In simplifying the process of monitoring the temperature of electric vehicle batteries, especially in discharging conditions, a remote electric vehicle battery temperature monitoring system was created. The problem with the previous monitoring system was that there was no electric battery temperature monitoring system, so users could not monitor the temperature condition of the vehicle battery when in use. The purpose of this study is to design an Internet of Things (IoT)-based electric vehicle battery temperature monitoring device system using the web and add a data logger to monitor battery temperature remotely and find out the difference in temperature values from the device with a thermogun. And the addition of a cut off feature when the battery overheats as one of the safety.
The research method uses experiments, namely by comparing the speed between 30km/h and 50km/h and comparing the readings of the monitoring device with a thermogun. In proving the performance of the monitoring equipment, it is carried out with a distance of 1km, 2km, and 3km and in sloping road conditions. The data obtained were then analyzed using the paired T-test method. The results of the study showed that the tool worked quite well with the highest error value of 3.88%. And the battery temperature value between the speed of 30km/h and 50km/h is a significant difference with a P-value result of 0.035 which means that H0 is rejected and H1 is accepted.

<p class="IndexTerms">This paper addresses the prevalent issue of increasing crimes in Indonesia, particularly vehicle thefts. To combat this challenge, we propose the development of an Internet of Things (IoT)-based vehicle security device capable of detecting intruders within the car and subsequently notifying the car owner through smartphone alerts. The implementation of this innovative technology holds the potential to enhance vehicle security and contribute to a safer environment for vehicle owners in the country.    In this study, we conducted a series of tests in a rural mountain area to examine the impact of vehicle and smartphone distance variation, as well as internet provider variation, on the response time of a vehicle safety device under limited internet signal conditions. The experiment involved distance variations of 100m, 200m, 300m, 400m, 500m, and 600m, with the internet providers being the most expensive and the cheapest provider in Indonesia. By investigating these factors, we aimed to gain insights into optimizing the response time of the safety device, especially in areas with poor internet connectivity<span lang="IN">. </span>Utilizing the two-way ANOVA method, this experiment successfully demonstrates that variations in distances and internet providers significantly influence the notification response. The effective combination of the HC-SR501 passive infrared sensor and Nodemcu microcontroller is shown to detect movements inside the vehicle cabin and reliably notify the vehicle owner through their smartphone. These findings underscore the viability and efficiency of the proposed system in enhancing vehicle security and owner awareness.</p>