We want to use a battery pack with two 1500mAh LiFePo4 18650 cell's in series. In the pack is a Fuel Gauge integrated (we did not select one yet).
We use the battery pack in standby use, so mainly it is just waiting, fully charged, until the mains fails. Every month the battery pack is tested by discharging it with a constant current comparable with the normal running load (about 1,5A) and also a high short current piek discharge is periodically applied (let say ever 10 seconds a peak current of 3A for 100ms (or a burst of shorter peaks) and off course after this the battery pack is charged again with 0.2C.
The question is: Can the fuel gauge reliable determine the SOH, if the battery pack is just used for a hour or even shorter every month? Testing every week is possible but not desirable.