TAN002 - Smart Solar Power System MPPT Controller Battery Mode Failure

Power failure affecting devices powered by Smart Solar Power Systems following a prolonged outage.

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 an issue affecting a subset of the batteries. When the battery voltage fully discharges to the point where the Multi-Point Power Tracking (MPPT) controller and Battery Management System lose power, their settings revert to factory defaults. These default settings do not support the LiFePO4 cells used in the Smart Solar Power System and lead to battery malfunction.

This does not happen under normal conditions, as the battery has a sufficient gap between when the sensor shuts off and when the MPPT controller resets. However, if the MPPT controller is left turned on for long periods of time (>2 weeks), this failure can occur. In practice, this can happen when:

• the battery is deployed for long periods of sub-zero temperatures

• the battery is put in long-term storage with the solar panels connected, a MODULAIR-X sensor connected, or a DC-DC converter connected

Identifying impacted devices

A sensor connected to a battery exhibiting this issue will repeatedly go offline or stay offline indefinitely. All LEDs on the base of the battery will be fast flashing.

Issue mitigation

Contact QuantAQ support if this issue is observed.