Battery Health Monitoring for Solar PV | IoT for Better Performance (2025)

As solar energy systems become more common across industries, rural infrastructure, and commercial buildings, a significant focus remains on generation metrics—how much energy the solar panels are producing, how efficient the inverters are, or whether the grid is absorbing the output.

But one component is often overlooked, yet it’s the most critical for reliable performance beyond daylight hours: the battery.

Battery banks in solar systems—especially in off-grid, hybrid, or backup-based models—are tasked with storing excess solar energy and discharging it when needed. However, despite their importance, batteries are frequently poorly monitored, resulting in early failures, hidden inefficiencies, and missed performance opportunities.

Most solar operators are unaware of what’s happening inside their battery banks. They know the system is running, and perhaps that the batteries charge during the day and discharge at night—but they can’t see the “how” or the “how well.”

Without proper visibility into battery health, operators miss out on vital metrics such as:

• State of Charge (SoC): This indicates how much energy is currently stored in the battery. Without real-time SoC tracking, operators can’t plan loads properly, leading to over-discharge or energy waste.

• State of Health (SoH): SoH tells you how much of the battery’s original capacity is still usable. Over time, all batteries degrade. But if you don’t know how quickly that’s happening, you can’t plan replacements or preventive actions.

• Voltage and Current Trends: Monitoring voltage and current under different load and temperature conditions helps detect issues like internal resistance build-up or uneven cell balancing.

• Temperature Readings: Batteries, particularly lithium-ion types, are sensitive to heat. Elevated temperatures can accelerate chemical breakdown, while low temperatures reduce performance. Without temperature visibility, it’s easy to overestimate the battery’s health.

This lack of transparency is not just a technical problem—it has business consequences. Downtime, unexpected replacements, warranty disputes, and oversized battery systems all stem from not knowing enough about battery behavior.

One of the most common yet overlooked challenges in solar PV systems is the underutilization of battery storage capacity. Battery banks are often sized generously, with the expectation that they will handle large loads, store surplus solar energy, and provide reliable backup. However, in reality, many of these batteries remain only partially used.

In numerous installations, operators find that less than 60% of the total storage capacity is regularly utilized. This mismatch between installed capacity and actual usage leads to several inefficiencies:

• Wasted Energy: Solar power that could have been stored for later use is effectively lost due to limited battery engagement.
• Under-leveraged Infrastructure: Expensive battery assets sit idle for long periods, providing limited functional value.
• Inefficient Capital Investment: Money is spent on capacity that isn’t delivering proportional returns, affecting the overall economics of the solar project.

This issue is often not immediately visible because most systems do not include tools to measure Battery Capacity Utilization—the percentage of available battery capacity that is actively being used over time.

To illustrate: consider a solar plant with a 100 kWh battery system. If only 50 kWh is used before the battery re-enters a charging cycle, half the capacity remains untapped. Over weeks and months, this results in missed storage opportunities, suboptimal load management, and a delayed return on investment.

Identifying and addressing underutilization is essential for optimizing performance, ensuring financial efficiency, and fully realizing the value of solar + storage systems.

This is where DATOMS Smart Solar Monitoring Platform makes a meaningful difference. By integrating battery health diagnostics into the broader solar monitoring ecosystem, DATOMS offers a single, centralized platform that captures all critical metrics in real-time and makes them actionable.

Here’s how it works:

• SoC and SoH Tracking: The system continuously monitors the battery’s charge level and estimates degradation trends over time. Operators can see how the battery ages across seasons or usage cycles.

• Charging and Discharging Insights: Track how energy flows in and out of the battery. See if certain loads are causing rapid discharge or if charging is uneven or incomplete.

• Battery Capacity Utilization Metrics: Understand how much storage you’re using versus how much is available. This helps in resizing, reconfiguring, or even repurposing batteries across locations.

• Temperature and Voltage Monitoring: High-resolution temperature and voltage tracking enables predictive maintenance, alerting you before battery packs fail.

All this data is brought together in one dashboard. Whether you’re managing a rooftop installation in a factory, a remote cold storage unit, or a utility-scale hybrid solar plant, you can monitor the health of your batteries from anywhere.

The financial returns from a solar PV system depend not just on how much energy it generates, but also on how efficiently that energy is stored and used.

With real-time battery monitoring, you unlock multiple layers of ROI:

• Preventive Maintenance Saves Costs: Instead of reacting to failures, you plan battery servicing or replacements based on real degradation data.
• Longer Battery Lifespan: By avoiding over-discharge, overcharge, and thermal stress, you extend the usable life of each battery—delaying replacements and reducing total cost of ownership.
• System Optimization: Align battery usage with solar generation patterns and load demand, so you don’t oversize or misconfigure components.
• Better Warranty and Compliance Tracking: Many battery OEMs require operational logs to process warranty claims. With DATOMS, your data is already in place—timestamped, centralized, and audit-ready.

DATOMS doesn’t just provide a set of sensors or charts—it delivers a comprehensive IoT-driven monitoring ecosystem that unifies:

• Solar panel performance
• Inverter analytics
• Energy Meter
• Battery health monitoring
• Load analysis
• Diesel generator (DG) integration (for hybrid systems)
• Environmental data (humidity, ambient temperature, etc.)

This makes it easier for plant operators, facility managers, and EPC contractors to make data-driven decisions that directly impact energy reliability, system lifespan, and operational efficiency.

In the rapidly evolving landscape of solar energy, the systems that succeed will be the ones that are smart, connected, and well-monitored.

Batteries are too expensive—and too important—to be left in the dark.

Whether you’re planning a new solar installation or managing an existing one, integrating Battery Health Monitoring is no longer optional. It’s a strategic move to unlock full system performance, reduce risks, and accelerate return on investment.

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