The Battery is more like 12 volts DC. I have also used a small car battery and now my UPS works like a real power inverter. I don't remember the last time my UPS completely discharged. It lasts hours. I have a heavy duty old laptop and router connected to it. The laptop has a desktop chip and 17 inch screen. The battery in laptop is useless so my ups works like a charm.
At first, I also replaced it with a ups small (toy)battery which was the replacement for the original battery inside. Cost me like 700 pesos. What a mistake, the damn thing didn't even last 3 month and only gave me like 5-10 minutes max then it went down hill from there. I have been using my current set up for months now and my battery is still strong and my UPS stays on for hours.
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