Question 1

Charger and Inverter Settings

Accepted Answer

Charger and inverter settings for SOK batteries General settings that apply to most equipment. Multiply voltages by 2 for 24v systems and by 4 for 48v systems. Charge Current (Per battery): 0-40a Preferred (50a Maximum) Absorption Voltage: 14.6v preferred (14.4 Minimum) Float Voltage: 13.8v preferred (13.6 Minimum) Equalization: DISABLED Low Voltage Disconnect (LVD): 11v Equalization: MUST BE DISABLED. SET DURATION TO 0 MINUTES. If you can, we recommend setting the equalization voltage to 14.6v. With this set at 14.6, if an equalization is somehow triggered, you will not damage your battery. Victron Settings For SmartShunt & BMV-712 / SOK Battery Battery Capacity: Varies depending on system. Charged Voltage: 13.8 (\ 2 for 24v & \ 4 for 48v Systems) Discharge Floor: 10% Tail Current: 2.00% Charged Detection Time: 3m Peukert Exponent: 1.05 Charge Efficiency Factor: 98% Current Threshold: 0.10a Time-to-go averaging Period: 3m Battery Starts Synchronized: Disabled (NOTE: you will need to fully charge your battery to sync up SOC%) State of Charge: 30% (NOTE: Set this to 30% with brand new, untouched batteries. They ship at 30% SOC%.) Comment on Discharge floor: Let’s say you setting this at 10%; when you get to 10%, the Smartshunt will indicate 10% remaining and 0 minutes until empty. If you choose to fully discharge your battery (not recommended) then set this to 0%. If you want to be more conservative on your time remaining, then set this to 20% Settings for Victron MPPT Charge Controllers: Battery Voltage: Set depending on system, normally 12v. Max Charge Current: OK to set as high as desired, but no more than 50a per battery Charger: Enabled Battery Preset: User Defined Expert Mode: ON Absorption Voltage: 14.6v Float Voltage: 13.8v Equalization Voltage: 14.6v Rebulk Voltage Offset: 0.40v Absorption Duration: Fixed Absorption Time: 15 Minutes (This allows for proper cell balancing) Tail Current: Disabled Equalize Current: 0% (For safety we don’t want equalization at all.) Automatic Equalization: Disabled Equalize Stop Mode: Automatic (On voltage) Maximum Equalize duration: 0 Minutes Manual equalization: DO NOT CLICK START Temperature Compensation: Disabled Low Temperature Cutoff: Disabled (unless you add a temp sensor, the BMS has this protection built in) Settings for Victron Blue Smart chargers: Victron’s Li-Ion profile is NOT sufficient for non-Victron LiFePO4 batteries. Enter configuration and turn on “ADVANCED” switch, then select “Custom” charge preset. Then click “Advanced Battery Settings”. The battery preset should be set to “User Defined”. Turn on “Expert Mode” switch. Charge Voltage Settings: Absorption Voltage: 14.6v Float Voltage: 13.8v Storage Voltage: 13.6v Recondition Voltage: Disabled BatterySafe: Disabled Voltage Compensation: Temperature Compensation: Disabled Bulk: Bulk Time Limit: 24 Hours Re-bulk Current: Enabled, set to full output current of charger, typically 25A Absorption: Absorption Duration: Fixed Absorption Time: 1 Hr Repeated Absorption: Every 7 days Recondition: Recondition Stop Mode: Fixed time Recondition Duration: 15M (This is the minimum allowed setting. It is already disabled in charge voltage settings, but set to this as a safety precaution)

Question 2

Charging Lithium Batteries in Vehicles: Considerations and Safeguards

Accepted Answer

Introduction Lithium batteries are rapidly becoming the preferred choice for a wide range of applications, including vehicles, due to their numerous advantages such as higher energy density, longer life cycles, and faster charging capabilities. However, they come with unique characteristics and charging requirements that differ from traditional lead-acid batteries. Low Internal Resistance One of the most significant differences between lithium batteries and traditional lead-acid batteries is their internal resistance. Lithium batteries have a much lower internal resistance compared to lead-acid batteries. While this feature allows lithium batteries to deliver high current outputs efficiently and charge rapidly, it also has implications for the vehicle’s charging system. Implications for the Alternator The alternator’s primary function is to supply power to the vehicle’s electrical system and charge the battery while the engine is running. However, due to the low internal resistance of lithium batteries: 1. Higher Demand: Lithium batteries can demand the maximum charging current from the alternator. 2. Risk of Overheating: If the alternator is not designed or conditioned to handle this high current demand, especially if it lacks sufficient cooling, it can overheat. This can lead to premature wear, potential damage, or even failure of the alternator. Victron DC-DC Chargers and Balmar Regulators: For those looking to safeguard their alternator and ensure a stable charging process for their lithium batteries, the use of a Victron DC-DC Charger or Balmar regulator offers a suitable solution. Functionality The Victron DC-DC charger is installed between the starter battery and the house battery. The Victron DC-DC charger not only limits the current flow, it isolated the batteries from each other when the ignition is turned off and provides the correct voltage for charging the house battery. 1. Charge Control: It automatically compensates by limiting the charge current to the lithium battery. 2. Protection: By doing so, it ensures that the alternator remains within safe operating temperatures, thereby prolonging its lifespan and preventing potential damage. 3. Configurable charging voltage: All of the Victron DC-DC chargers can also be programmed to provide an optimized charging profile tailored to the specific requirements of lithium batteries, ensuring safe and efficient charging. The Balmar regulator or equivalent monitors the alternator’s temperature in real-time. When the regulator detects that the alternator is approaching a critical temperature threshold: 1. Charge Control: It automatically compensates by reducing the charge current to the lithium battery. 2. Protection: By doing so, it ensures that the alternator remains within safe operating temperatures, thereby prolonging its lifespan and preventing potential damage. 3. Optimized Charging: Apart from temperature management, the Balmar regulator can also be programmed to provide an optimized charging profile tailored to the specific requirements of lithium batteries, ensuring safe and efficient charging. Conclusion While lithium batteries offer a multitude of benefits, especially in vehicular applications, they come with unique charging characteristics. The low internal resistance, while advantageous in many respects, poses challenges to traditional charging systems like from the vehicle’s alternator. Employing solutions like the Victron DC-DC charger or a Balmar regulator can help navigate these challenges, ensuring both the battery and alternator remain safe and functional in the long run.

Question 3

DC-DC Chargers and why we need them

Accepted Answer

Are you wanting to know more about DC-DC battery chargers and how they can enhance your campervan’s functionality? Let’s dive in. Maintaining a reliable electricity supply in your van is essential, particularly for extended journeys. It ensures your van stays illuminated, energizes your electrical outlets, and powers vital appliances like your refrigerator, heating system, and water pumps. There are a few methods to recharge your campervan batteries, including: • Alternator (DC-DC) • Solar, and • Shore Power (Plugging it in); this method necessitates an inverter/charger. One component that raises a lot of questions is the DC-DC battery charger. What is a DC-DC battery charger and why do you need it? In this guide, we’ll discuss: • The definition, function, and significance of a DC-DC battery charger. • A brief comparison of the DC-DC battery charger with other alternatives. Let’s get started! What is a DC-DC Battery Charger? Simply put, your vehicle’s alternator produces electricity and charges the vehicle battery while you’re on the move. In a campervan, you use this same alternator to charge your house batteries. These batteries power the internal components of your campervan, like lights, and are typically Lithium or AGM batteries. By default from the factory, your alternator is set up to know when your vehicle battery is charged and how much power the alternator needs to put out. It’s not designed to know about the campervan conversion you have going on in the back. That’s where the DC-DC Battery Charger comes in. Why do You Need a DC-DC Charger? To understand why a DC to DC chargers are required, it is best to understand a little about the differences between lead acid batteries and lithium batteries. Lead acid based batteries exhibit higher internal resistance to charging, which in turn reduces the demand from the alternator. Conversely, lithium batteries have very low internal resistance. As a result, when a lithium battery is connected to an alternator, it demands maximum output. While your alternator may handle this while the engine is running at high speed and adequately cooled, the same load can damage the alternator when it is idling due to insufficient air flow, leading to an increase in temperature and potential burnout of the windings. In short, the DC-DC Battery Charger is the brain that acts as a gateway that provides the correct voltage for charging the Lithium battery and acts as a current limiter. Alternator - DC-DC Battery Charger - House Battery How Does a DC-DC Battery Charger Work? The DC-DC battery charger uses your van’s alternator (an electrical generator) to convert the available power. It then converts that power to a higher voltage for your secondary battery (i.e. your house battery). Here’s how the DC-DC charger uses a 3-step process to charge your battery optimally. 1. Bulk: In this step, the DC-DC battery charger converts the current from the alternator and fills in the secondary battery almost to the maximum. 2. Absorption: Here, the power levels off and stabilizes so the battery doesn’t ‘overcharge’. 3. Float: This occurs when the battery is fully charged with its optimal capacity reached. Understanding the Advantages of a DC-DC Charger Let’s delve into several advantages you’ll experience when utilizing a DC-DC charger. Navigating Smart Alternator Challenges Present-day vans typically have smart alternators that are created to lessen power output. Due to their load limitations, these alternators can’t charge a secondary battery. However, a DC-DC converter eliminates this hurdle by separating the primary battery from the alternator. Enhancing Main Battery Charge Installing a DC-DC battery charger has another perk – maximizing the primary battery’s charge. This charger can transform voltage from as low as 9 volts to as high as 13.5 volts, enabling quick and effective charging of the main battery. Functionality Without Solar Power If you often travel in regions with limited sunlight, a DC-DC charger can be a significant advantage. These chargers can charge an auxiliary battery, enabling you to power your devices without relying on solar power or other backup energy sources. Compatibility with Various Battery Types One of the most notable advantages of a DC-DC battery charger is its ability to adapt to different battery types. This feature can save you the time and expense of purchasing a new charger whenever you replace your battery. Moreover, a DC-DC charger can tailor the power based on the battery’s intended use, reducing battery damage from overcharging. Can I Use a DC-DC Charger with Lithium Batteries? Yes, you can definitely use a DC-DC charger with lithium batteries as it can optimize your battery life. A DC-DC charger can also extend your lithium battery life. Here’s a summary of its functions A DC-DC charger provides the correct voltage to the lithium battery, ensuring the charging voltage is not exceeded. A DC-DC charger effectively controls the power demand from a lithium battery, ensuring it doesn’t overheat the alternator when charging. Lithium batteries have a unique restart process and specific battery chemistry, complicating their charging through alternative methods, like an alternator. At SOK Battery we recommend Victron DC-DC Chargers Victron DC-DC chargers such as the Orion-Tr Smart isolated/non-isolated are one of the most popular brands in the market right now with the following features: Works well with both 12-volt and 24-Volt systems and lithium and lead-acid batteries. Includes Bluetooth so you can control the power settings from the comfort of your cellphone via an application. It is durable and can adapt to high temperatures. Includes a switchable remote loop to enable and disable the DC-DC charger remotely

Question 4

Changing over to Lithium

Accepted Answer

When transitioning your camper or caravan from lead-acid to lithium batteries, it’s important to securely fasten, correctly charge the lithium batteries and if applicable protect the batteries from freezing temperatures if using a non heated battery. Charging Procedures The charging process for lithium batteries differs significantly from that of lead-acid batteries. Many older chargers, whether solar or mains, may not be compatible. To verify the compatibility of your solar charge controller or mains charger, refer to the manufacturer’s user guide. Look for either a lithium mode or a user-programmable mode. If your charger offers a user-programmable mode, it allows you to establish the proper charging voltages and disable battery equalization. Lithium batteries necessitate a constant current at a predetermined voltage for charging. Generally, the absorption voltage is set between 14.4 to 14.6 volts, while the float charge is adjusted to 13.8 volts. The equalization process is not required. If your charger is equipped with a lithium mode, the default lithium profile can often be used. Depending on your batteries’ charging requirements, you might need to adjust this profile slightly. If your charger is not compatible, you will require a DC-DC charger such as the Victron Non-Isolated DC-DC charger. These chargers which are smart alternator compatible, not only protect the lithium battery, they also separate the batteries from each other when the vehicle is turned off. Vehicle Charging Our comprehensive knowledge base includes an article detailing the necessity of a DC-DC charger for charging lithium batteries from an alternator. You can find this article here (https://sokbattery.co.nz/knowledge-base/charging-lithium-batteries-in-vehicles-considerations-and-safeguards/). If you possess a large battery pack or require rapid charging, you can directly charge a lithium battery pack from an alternator equipped with a Belmar regulator. This setup is occasionally used in boats or yachts where engine run-time is limited and quick charging is crucial. For more information on this setup, feel free to contact us. Temperature Considerations AGM batteries have the advantage of being more tolerant of cold temperatures than lithium batteries. Lithium batteries will not charge below freezing and should be kept in a temperature-controlled environment (for example, inside your van or in an insulated enclosure), unless they have an inbuilt heating element. The SOK BMS ensures that the battery is not charged below 0 degrees to prevent any potential internal damage due to such situations.