WaterSecure Battery Low Capacity

There could be many reasons for your batteries to have a lower capacity than expected. Some common issues we face are:

Battery Under Charged/Over-Charged: Every battery has its charge/discharge cycle. A battery that is continuously under-charged or over-charged cannot maintain its rated lifespan or capacity. Another thing to consider is that, batteries must not be over-discharged. In-fact, batteries are not expected to be discharged below 0.5V per cell.

Battery Charges/Discharges fast: If the battery shows full charge too early, meaning it reaches its full charge earlier than usual, which consequently also determines the discharge rate, it may be the first sign that the battery is getting weak. A strong battery takes longer time to be fully charged and also longer time to discharge. However, in a battery array that involves two or more batteries joined together, failure of one battery in the string may affect the performance of other batteries in the array. The strength of all the batteries in a string is determined by the capacity of the weakest of them in the array. This also explains why weak and strong batteries should not be combined in a battery array. Another important thing to consider is when battery discharges faster but takes longer time to be fully charged. In this case, you need to evaluate total load connected to the Inverter to find if there is a hidden heavy load draining the battery. If a battery takes a long time to be full but discharges faster than expected, it may mean that there is too much load feeding from the battery. Shed some heavy loads and observe any difference. Another problem that can cause battery to have low voltage is when the battery has been left in a deeply discharged condition for long without recharging, it develops what is called insufflation which may be irreversible, and it may be impossible to revive such a battery again. A dry cell battery loses 2% of it's voltage every 30 days if left in a discharged condition.

Loose battery terminals: If the battery terminals are loose, high resistance will be built around the terminal that will prevent or reduce the flow of charging current to the battery. This can result to arching (sparking) around the terminal and in extreme cases can result to fire. Ensure all battery terminals are firm.

Point To Note: Inverter or UPS should not be loaded above 80% of its rated capacity for three basic reasons:
One, possible future expansion of load.
Two, maximum efficiency of the machine. Loading machine to full load will lead to low efficiency (performance) and consequently pre-mature failure. I would suggest looking into the health of your battery bank and consider upgrading to the large 160ah batteries and possibly adding more panels as well to further accommodate your load.