Checking rechargable batteries

[GoatZero]

5 years ago i didnt know anything about electricity or electronics, now i do

5 years ago my UPS batteries died so i teared it down to replace them

Today the batteries i replaced seem to have died once again however i think something is wrong

1 week ago i still could get around 10 minutes of energy and suddenly i dont even get 1 second,

now i own a multimetter and an osciloscope and i was wondering about if is theres a way to check how good or bad is the battery is by using these tools

[Psi]

what is a "no break"

[GoatZero]

what is a "no break"

lol sorry in my country we call them no break in english its actually Uninterruptible power supply UPS, it uses 2 Lead acid batteries

[Stonent]

What country is that? Your flag looks black to me.

[tszaboo]

what is a "no break"

lol sorry in my country we call them no break in english its actually Uninterruptible power supply UPS, it uses 2 Lead acid batteries

This is not the first time, seriousy, where are you from?

Charge the betteries with a lab psu, CC/CV mode with 0.1C for 10 hours. Measure voltage. Connect a load to it, measure current and voltage. Calculate capacity.