How to Spot a Dying Solar Battery: 10 Must-Know Warning Signs
If you’ve installed a solar battery, it’s crucial to be alert for signs of failure. A failing battery can reduce savings, cause disruptions, or even pose safety risks.
Here are 10 clear indicators that it might be time to inspect—or replace—your solar battery.
1. Your Battery Isn’t Holding a Charge
If your battery shows full charge midday but drains quickly afterwards, the internal cells may be degrading
2. Unexpected Power Outages or Backup Failures
Missed nighttime power or failure during a power cut is a key warning sign
3. Terribly Slow Charging
Charging that’s noticeably slower than when new often indicates internal resistance or cell damage.
4. Warning Lights or Error Codes
Red or flashing lights and error codes on your inverter or battery interface shouldn’t be ignored
5. Hissing Sounds, Popping, or Swelling
Unusual noises or swelling suggest serious chemical or mechanical issues—seek professional help immediately
6. Increasing Electricity Bills
If your bills are rising despite using stored solar power, the battery may not be discharging correctly
7. Deep Discharge More Often
If you’re going below the recommended Depth of Discharge (DoD) regularly, battery life can deteriorate quicker
8. Variable Performance Across Seasons
Performance swings—especially beyond expected seasonal variation—can indicate a weak battery
9. You’ve Reached Battery End‑of‑Life
Most lithium batteries last 10–15 years; lead‑acid 7–12. If yours falls in that range and shows issues, replacement is likely due.
10. Overheating or Sensitivity to Temperature
If your battery overheats or underperforms in mild weather, that’s a major red flag.
Why These Issues Happen in the UK Climate
Our damp and variable climate can stress batteries. Undercharging during winter, and overcharging or overheating in summer, speeds up cell degradation.
How to Check Solar Battery Health
Monitor your inverter or battery dashboard daily
Perform full charge–discharge cycles to test capacity
Use a multimeter for voltage testing (especially on lead-acid)
Schedule annual health check-ups with our certified technicians
How We Test Batteries at Green Tech
Voltage and resting voltage tests to check cell health
Load tests to measure performance under real-world conditions
Specific gravity checks for lead-acid batteries
6 Tips to Prolong Your Battery Life
Pair the right panel-to-battery ratio
Install in a ventilated, temperature-stable space
Avoid excessive deep discharges
Keep your system firmware and BMS up to date
Clean and inspect connections regularly
Use a hybrid inverter/back-up gateway for smooth operation
Should You Repair or Replace Your Battery?
Minor electrical/software issue- Try repair (especially if under warranty)
Major capacity loss or cell damage- Likely better to replace
Battery >10 years old- Consider an upgrade for efficiency
Don’t Let a Faulty Battery Cost You
At Green Tech Solar Ltd, we offer full diagnostics, expert advice, and quotes to repair or replace your solar battery. Whatever your needs—whether backup power, cost savings, or peace of mind—we’re here to help.
Ready for a battery health check?
Contact Green Tech Solar Ltd today for a free, no-obligation assessment. Let’s make sure your solar battery is working as hard as your system does.
Green Tech Solar Ltd – Your Energy, Our Expertise.
