TAN003 - Smart Solar Power System Battery Cell Connection Failure

Power failure affecting devices powered by a specific batch of Smart Solar Power Systems.

This issue does not impact the safety of the battery in any way, and there is no immediate action that is required. This issue does not affect the performance of the Smart Solar Power System, only our ability to log performance data.

Issue summary

The third-party vendor that supplied the batteries used in the Smart Solar Power System has informed QuantAQ of a hardware issue affecting some of the batteries. Affected units contain LiFePO4 cells with defective inter-cell contacts. The joint between cells has abnormally high resistance, so the pack cannot deliver current under load even when it holds a nominal state of charge.

Identifying impacted devices

Batteries shipped after July 14th 2025 or serial number >650 may be affected by this issue. If you received a system outside this window, the symptoms below are unlikely to be this failure - contact support so we can diagnose separately.

Batteries with this issue will go into low voltage protection mode (fast flashing amber LED) immediately or within 15 minutes of connecting a load while the battery is not charging. A sensor connected to a battery exhibiting this issue will only stay online when the battery is actively charging. When the input power drops or goes to zero (e.g., nighttime or overcast), the sensor will go offline, or stay online for up to 15 minutes before powering down. If solar data is available, the load voltage will appear to fluctuate rapidly between 14V and close to 0 V.

Issue mitigation

Contact QuantAQ support if this issue is observed. Include your sensor serial number, battery serial number, and approximate deployment date.