Video : 
New battery for my 48Volt battery bank. I drain the battery to see how many watt hours I can expect to get out of it.
The battery is not super great but good enough for me to continue and connect it to two APC 1000VA UPS.
Unfortunately, it does not seem that the two UPSes will help to share the 48Volt, but will only run with their own bank of 24 volts.