In this article, I’ll guide you through the symptoms of a bad battery current sensor.
As an electrician, I have vast experience troubleshooting bad battery current sensor issues easily. Knowing the symptoms of bad battery current sensors will help you to avert further damage to the battery or other parts of the car.

What are The Signs of a Faulty Battery Current Sensor? When the battery current sensor fails, the vehicle does not charge properly, which results in a DTC or a dead battery.
Common failure indicators include:
- Inconsistent charging rates
- Battery voltage is low
- Corrosion on the battery or the sensor connection
- Sensor cabling that is broken or bare
I will go into detail below.
Battery Sensor Issues

Dirt, moisture, and battery acid contamination
The most common issue occurs when dirt, moisture, or battery acid enters the sensor, damaging or shortening it.
In some BMW vehicles, for example, the battery is located in the trunk’s side compartment, and water leaking into the battery can damage the sensor. The Intelligent Battery Sensor, or IBS, is what BMW calls it. A failed IBS has been linked to several electrical issues, including a no-start. A battery sensor is a delicate device that can be damaged during battery servicing or removal.
A faulty battery sensor can cause the Charging System Indicator to incur trouble code (DTC) P154A, according to Honda bulletin 16-026 for several Accord, Fit, and HR-V models. The battery sensor should be replaced, according to the bulletin. In some Acura vehicles, the code P154A can also be caused by a faulty battery sensor.
Honda issued the recall (service bulletins 17-057 and 17-069) to inspect and, if necessary, replace the battery management sensor in Honda Accord models from 2013 to 2016. (except Hybrid). Moisture and road salt getting into the sensor, according to bulletin 17-069, “could result in an electrical short and, consequently, a fire.”
Current Bypass
Suppose a car has a battery current sensor and additional electrical accessories connected directly to the battery’s negative terminal.
In that case, the electric current will bypass the battery current sensor, resulting in inaccurate readings. To ensure proper operation of the battery management system, the owner’s manual for the 2019 Ford Explorer recommends not connecting electrical devices’ ground connection directly to the low voltage battery negative post (BMS).
A faulty battery sensor in many vehicles can render the Stop/Start system inoperable.
The battery sensor is inexpensive to replace. A mechanic may charge you $50-$210 for the part, plus $35-$110 for labor. In some vehicles, a battery sensor is included with the battery cable. The toughest part is correctly diagnosing the problem, which is not always easy.
Replacing Faulty Battery Sensors — Precautions

The following precaution must be taken when changing battery current sensors:
The sensors are delicate and can be permanently damaged if installed incorrectly. Because each car battery management system operates differently, it is critical to read the user’s manual.
It is advised to seek professional assistance when replacing the battery current sensor. The battery current sensor is priced at AED 400.
The Working Principle of a Battery Sensor
Warning Light for The Battery Sensor.
Battery sensors are linked to the car computer and display a warning light if there is a discrepancy.
The battery current sensor is located at the terminal clamp and is secured to the car frame with screws. A shunt in the sensor measures current and temperature, which are essential parameters for a car computer. BZE algorithms in a car computer use these signals to detect the battery’s health, state of charge, and function. Here, health, charge, and functions stand for:
Battery health refers to a battery’s ability to store and supply current.
State of Charge: It specifies the amount of charge remaining in the battery. The amount of charge left determines fuel efficiency and current usage. (1)
State function predicts the relationship between a voltage curve and a load profile.
Wrapping Up
This was all about vehicle battery current sensors. Battery sensors are the most recent type of sensors that have replaced manual battery maintenance processes. These sensors cater to the increased demand for electrical functions. If you’re driving an old car without battery current sensors, it’s time to replace it. (2)
Take a look at some of our related articles below.
- How to charge a 6-volt battery
- What gauge wire to connect two 12v batteries in parallel
- Multimeter setting for car battery
References
(1) fuel efficiency – https://www.caranddriver.com/research/
a32780283/fuel-efficiency/
(2) old car – https://www.nationwide.com/lc/resources/auto-insurance/articles/how-old-is-a-classic-car
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