Question Mecer 1.2KVA inverter

[Vlad.-.]

I recently bought a Mecer 1.2KVA inverter and paired it with a Mecer 12v 100AH deep cycle lead acid battery. It works fine if the power goes off it switches over without fail and it is able to handle my gaming setup the inverter says it is at about 50% load when my gaming PC in running. However, once the inverter says the battery is at 50% it starts beeping saying "low Batt" is this normal or not? Should I maybe add a second battery?

 

[BFG-9000]

Yes, this is perfectly normal for lead-acid batteries because for longevity you generally do not want to discharge them below 50% state of charge.

For your deep-cycle lead acid battery, the difference is 500 cycles life vs. only 200 at 100% discharge. Unfortunately the alarm is because these UPS manufacturers don't tend to use deep-cycle type batteries in their products, usually favoring cheaper sealed/maintenance-free gel cells which last about 100 cycles to 50% discharge vs. only about 10 to 100%. So a 10-fold increase in cycle life by only discharging to 50%.

Adding a 2nd 100Ah lead battery would allow you to draw the same power for twice as long, but would then take twice as long to charge back up, provided the built-in charger was up to the task. Or if you replaced the battery with a 12.8v LiFePO4 type the cycle life would go up into the thousands even if you discharged to 100%, with the caveat that the built-in charger may not be best for it (though perfectly acceptable with the built-in BMS on the lithium battery). If the power mainly goes out during the day, it would be reasonable to add a solar panel and charge controller to keep the battery from depleting as quickly.