Did you take a look at your battery? Mine has the most important specs printed on it: 80A/hr; 380 Cranking Amps.

This means, that fully charged it should be able to deliver, for example, 10A for 8 hours, and it should provide 380A for 30 seconds at 0 degrees F before the voltage falls to 7.20 V.

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Greetings Rainer
...and may there always be a palm of air around your sheetmetal...