Hello guys, today I wanted to bring my mop back to life, take me the battery and … see photo… Shit ! Minus pole ! the batt. I charged about 3 weeks ago, the acid level was ok, the voltage lay after the charging process over 13,5 V. Where comes this crusting (voltage is about 8 V,) the batt. I have always stored dry and warm. Besides, the 1st cell behind the minus pole is dry. Can someone tell me how this is coming from ? That a new batt. must come from, is clear, abe R why why? Vlt. has someone’s answer ready.