Power and battery management systems are an important part of overlanding because they make up your mobile power supply. If you are powering electronics such as GPS units, phones, tablets, light bars, refrigerators, inverters, radios and/or air compressors, it is crucial to be cognizant of the impact all of this can have on your battery. As your electronics add up, your battery can become over-taxed, especially on a full build. Fortunately, we’ve discovered several ways to increase the health, longevity and performance of your batteries and lifestyle while on the road.
But first, let’s get back to basics with an overview of the different battery types and how to use them in combination to create MORE POWER.
There are three main types of batteries that are used in overland builds.
1. Lead Acid Battery
This starting battery is the cheapest and easiest to use. Your vehicle most likely came with a lead acid battery.
2. AGM (Absorbed Glass Mat) Battery
These batteries are higher in price but are also more robust. The AGM can be used as both a starting and a house battery. They also resist vibration really well.
3. Lithium Ion Battery
Lithium Ion batteries have a much better drawing capacity, are lighter and more expensive when compared to an equivalently sized AGM battery. Depending on the applications, lithium works well as a house battery.
powering your overland rig with batteries
There are several ways to use these batteries to power your vehicle and its electronics.
Choose a large house battery to be charged by your alternator.
As long as you are driving every day, the alternator will charge this battery enough to maintain your power levels for a long time. Now, if you are stopped and parked frequently you will need to either a.) replenish the well through solar; or b.) deepen the well with more batteries.
Add solar panels.
If you are in an area with good sun and depending on your vehicle payload, this system could power your setup indefinitely by charging your house battery. A solar charge controller regulates the amount of power that is delivered from the solar panel to the battery bank.
Use a dual battery system.
This is a great option when the loads outweigh the capacity of the starting battery. The advantage of running a dual battery system is its ability to separate the load functions of the vehicle. Typically your starting battery powers the basic functions of the vehicle, your communications devices, a winch (if installed) and driving lights. This is best practice.
All auxiliary loads or accessories are then placed on the house battery (aka the auxiliary battery). A dual battery system in this configuration typically needs to be of the same chemistry as the start battery. For example, your starting battery and house battery would both have to be lead acid. If you choose to run mixed chemistry, you need to step up to a battery manager.
Run dual or triple battery systems plus solar.
If sized correctly, this system will run itself indefinitely.
battery isolators and battery management systems
A battery isolator isolates batteries so the alternator will only charge your house battery when the engine is running, preventing the electrical load from draining your starting battery.
You can manage dual batteries with a smart dual battery isolator (or “smart solenoid”), which prioritizes the starting battery. If the starting battery drops below a certain voltage, the smart dual battery isolator will shut off charge to the house battery, maintaining the starting battery’s power levels. National Luna and Equipt both offer smart solenoids.
A battery management system, on the other hand, draws power from the starting battery and solar panel(s) to charge the house battery. Benefits of this system include the ability to monitor and maintain the house battery at an optimal charge, allowance for three different chemistries of house battery, and an easy-to-read display showing battery usage and charge levels.
Electronics can be quite a complex matter akin to the “dark arts.” There will be specific applications for your vehicle. One of the above power systems might indeed be the solution for you, it just depends on the level of intricacy and complication that your build demands.