I purchased 4 off Victron Energy 12v 220Ah Gel Deep Cycle Batteries via Ebay on 2nd April 2017.
The batteries are installed on my narrowboat as leisure batteries.
The batteries performed well initially but, in recent weeks, the performance has deteriorated significantly.
The batteries now hold charge for less than 4 hours. They do not appear to charge fully. It now takes less than one hour to charge them from zero to fully charged.
I have been advised that It seems like the batteries have “memory issues” – they probably need to be taken out, discharged completely and then fully recharged.
Is there a procedure/method statement for completely discharging the battery?
I have been told (by others) that completely discharging the battery can lead to serious damage to the battery. Is there any truth in this?.