Electrical

Electrical system are becoming more and more complicated in modern vehicles, the vehicle battery is not only responsible to start the car, but also need to power all different types of device on the vehicle.

In this section, I included vehicle electrical system project that helps me to get backup battery power system. The advantage of a backup battery system is to eusure the vehicle can start in extreme weather condition and power auxiliary equipments.

Silverado Backup Battery System

I got this idea from RVs where the vehicle has two batteries. The vehicle battery or the start battery is the one that will start the vehicle, while the second battery or house battery will keep all the accessories running on the vehicle.

My intended purpose in installing this system is to put my light bar circuit and future modification circuits on the second battery to avoid draining the starting battery.

My vehicle is on the GM K2XX platform, so the engine bay has two locations for two batteries. The reason that the manufacturer included two battery locations in my vehicle is that there is a diesel variation of my vehicle and diesel trucks need two batteries to start the vehicle. My vehicle is a gas V8 engine, so I have the second battery position empty by default.

I sourced a Keyline isolator, Driver Side Battery Auxiliary Tray - GM (22989633), and a car battery for this modification.

Here are the State Transition Diagram and Output Flow for this system

I mounted the GM Driver side battery auxiliary tray on the driver's side, connected the positive to the isolator, and connected the isolator to the start battery of the vehicle. I connected the ground wire to the vehicle frame for grounding.

After installing the isolator and the second battery, I moved all the accessories’ power to the second battery.

I also used heat shrink and weatherproof sleeves to protect the electricals from corrosion and water damage.

The isolator will get charged when the start battery is charged from the alternator.

The second battery powers all the accessories on my car, and when the second battery is drained, it will not affect the start battery.

When the start battery is drained, the second battery will deliver power to the start battery to ensure it has enough power to start the vehicle and the alternator.

Result

After four years of driving in harsh weather conditions, the second battery system on my vehicle has no issues. When the start battery is aged and not holding charges well, the second battery ensures the vehicle start and runs before I replace the start battery.