battery charging

I topped up the battery recently until the green bar on the Motobatt charger lit up.( Yuasa battery : same as original) Then tried to start it, but only clicking occured. Checking battery voltage, it had only reached 11.45V. Another 2 hours or so of charging in green segment got it to 13v, with full starting re-established! Hurrah. Measuring voltage was a very useful check….!