The battery voltage drops when fed to the DC booster circuit

[leVanw]

I use a 12V battery to power a DC booster circuit. After just a moment, my battery's voltage decreased, causing the booster circuit to also decrease its voltage. Is there any way to make the battery last longer without losing voltage? Thanks

 

[berkeman]

What is the energy rating of your battery (in Amp-hours)? What current do you measure out of the battery when it is driving the boost circuit? What is the load of the boost circuit (output voltage and current)?

 

[leVanw]

What is the energy rating of your battery (in Amp-hours)? What current do you measure out of the battery when it is driving the boost circuit? What is the load of the boost circuit (output voltage and current)?

The output voltage of the booster circuit is about 40V, and I don't know what the energy rating of the battery is (I use a GP 23A 12V battery).

 

[berkeman]

GP 23A 12V battery

Link to the datasheet please.

The output voltage of the booster circuit is about 40V

Link to the datasheet please. What is the load? What is the output current?

(pulling teeth here...)