EV Battery Health: Insights from a Minit Charger Expert

At Minit Charger, innovation is at the forefront of our work. We focus on understanding and meeting the specific needs of Electric Vehicle owners. Our team, particularly our engineers, play a fundamental role in this effort. Their expertise enriches every product we create, as evidenced by our recent discussion with Ryan Kritz, a leading application engineer.

In our conversation, we focused on the importance of battery health for customer satisfaction. We addressed common issues like the effects of temperature on charging and the importance of following maintenance phases. Understanding these factors is crucial for EV owners, and here's what we learned:

?High and low-temperature charging?

If a battery is charged at a high temperature or allowed to continue charging after a high temperature is reached, significant complications can occur, such as:?

• Thermal Runaway Risk: High temperatures can induce thermal runaway in batteries, particularly lithium-ion types. Thermal runaway is a self-sustaining reaction within the battery that leads to rapidly rising temperatures and potentially to fire or explosion.?
• Accelerated Degradation: Batteries subjected to high temperatures during charging can experience accelerated chemical degradation. This degradation can reduce lifespan, lower capacity, and potential battery failure. Manufacturers design and test their batteries for specific temperature ranges, and operating outside these can lead to enhanced wear.

Ryan also warns against charging at low temperatures, citing it as a central issue in most support calls. When a battery is charged during periods where the temperature drops into the negatives, especially below freezing, specific battery chemistries can be significantly affected and may experience damage. This is particularly relevant for lithium-ion batteries. Here's a closer look at why and how this happens:

• Reduced Electrolyte Performance: In cold temperatures, the electrolyte in batteries becomes more viscous (thicker), which impedes the flow of lithium ions. This slowed movement of ions makes the battery less efficient and can reduce its ability to hold a charge.
• Lithium Plating: Charging a lithium-ion battery in icy conditions can lead to lithium plating. This occurs when lithium ions deposit as metallic lithium on the anode's surface instead of intercalating into the anode (carbon/graphite layer). Lithium plating is detrimental because it permanently reduces the battery's capacity and can create internal short circuits, leading to potential safety hazards like thermal runaway.
• Impacts on Charge Acceptance: A battery's ability to accept a charge is reduced at low temperatures. This means charging takes longer, and the battery may not charge fully.

While temperature-aware strategies can mitigate the risk of high/low-temperature charging, Ryan warns that they may not be foolproof. Instead, he suggests an intelligent approach to charging, turning to the Minit’s Line of chargers as an example, stating: “Our charger’s algorithm has variables that the customer can set that will either derate (scale down or back off) the current when temperatures rise to a specified level or stop the charge (or refuse to start) if a maximum temperature set by the customer is reached.”

Depth of Discharge

?All batteries have a recommended depth of discharge. Ryan explains, “If I charge the battery to 100% and then drain it, what % should I stop at to maximize its life? With FLA, it’s 20%. With Li-Ion, it’s 10%.”??

Neither Minit Charger nor Battery manufacturers can stop an owner from going below the discharge depth, but there are ways to detect this behavior. With the implementation of specific battery profiles in Minit Chargers, the risk of going below the discharge depth is mitigated by alarms and limits.?

Battery Maintenance Phases

In battery maintenance, particularly with older chemistries, an integral aspect is the implementation of an "Equalization cycle." This might sound technical, but a specially scheduled charge cycle is essential for maintaining a battery’s peak performance. As battery cells age and undergo numerous charge and discharge cycles, they can become imbalanced, with some cells having higher or lower voltages than others. An equalization charge is a deliberate overcharge, typically applied to lead-acid batteries, that ensures all cells in the battery bank reach an equal charge, thereby preventing sulfation and extending the battery’s lifespan.?

Ryan recommends a battery management system to simplify the process by automating and scheduling maintenance without requiring manual intervention. In the long run, using a battery management system will preserve a battery's health and efficiency and offer a hassle-free, set-and-forget solution to one of the crucial aspects of battery maintenance.?

Features recommended to be included in a battery management system are:?

• Detection: Your system's ability to detect when a battery has been discharged beyond its recommended DoD is crucial. This helps prevent further damage by avoiding attempts to recharge a deeply discharged battery under normal conditions.
• Refusal to Charge Normally: Refusing to charge a battery over-discharged under standard charging profiles is a safety measure. It prevents the risk of damage from rapid charging when the battery is in a vulnerable state.
• Battery Health Monitoring: Regular battery health monitoring can provide early warnings before a battery reaches a critically low state of charge. This helps in taking preemptive measures to maintain battery health.

Future of battery management?

Ryan highlights a feature in Celltrac, Minit’s Battery management system, set to revolutionize battery maintenance for FLA (flooded Lead acid), AGM (absorbant glass mat), and generally older battery technologies. This new advancement addresses one of the most significant and costly issues in battery care: low water levels. The innovative Celltrac system can alert users when the water levels in their batteries are running low, recommending a timely top-up at the end of the charging cycle. This proactive approach is crucial, as allowing water levels to drop—or worse, letting the cells dry out—can be a significant detriment to battery longevity and performance. This upcoming feature highlights Minit Charger's commitment to extending the life of older battery technologies, ensuring that maintenance is more efficient and effective in safeguarding these essential power sources.

Intelligent charging and maintenance practices are vital to maintaining the health and longevity of EV batteries. The advanced features of battery management systems, like those implemented in Minit Chargers, play a pivotal role in ensuring batteries operate within their optimal parameters. From detecting deep discharges to automating maintenance cycles, these systems are not just about preserving battery life; they're about enhancing the overall user experience.

It’s clear that the world of EV batteries is complex, but with the right tools and knowledge, it's navigable and manageable. Whether you're an EV owner or a service provider, understanding the nuances of battery care can make a significant difference. By embracing intelligent technologies and informed practices recommended by experts like Ryan, we can ensure our EVs run efficiently and sustainably. The future of EVs is bright, and with Minit Charger's commitment to innovation and expert guidance, we're set to drive into a cleaner, more efficient future. Remember, the power to keep your EV running at its best isn't just in the battery—it's in your hands.