I have numerous batteries on boats and cars and this has been marvellous.
I thought I had killed a boat battery but it took four days on this unit and came back to life and has been good since. The other day I did another boat battery and it was fully recharged within 15hrs.
How long should it take to charge a leisure battery for my boat? Any advice
It just depends how low the battery is, I have a smart charger and every now and again connect it up and leave it overnight. Its always on the maintain light when I next look.
Have a look on the battery and it should say how many amps it holds ,then look at the battery charger and it should say how many Amp hours it gives out .
some thing like,, Battery 12volt 20 Amp hours .
Charger 12 volt 5 amp hours
in theory battery should take 4 hours to charge up .
or if it was a 40 amp hour battery it would take 8 hours to charge at 5 amps
Battery charging is quite a complex issue. Sadly it is not as simple as dividing the capacity of the battery by the charger output for the simple reason that as the battery charges, its internal resistance will change and the charging current will reduce as the voltage rises.
Depending upon the 'trickle' charger output, some batteries may never get to fully charged. Smart chargers usually ramp up the charge current at the start and then drop down to a bulk charge level before moving to a lower rate to get the final bit in. On a big battery, a trickle charger may do nothing more than maintain a float voltage which will prevent self discharge but not actually do any proper charging.
Worth checking the battery (unless it's maintenance free), that's there's sufficient electrolyte solution to cover the cells/plates. If it needs topping up, then used distilled water (available from local autoparts store, or Halfrauds!) Makes the difference between a battery retaining the charge or becoming exhausted.
Sula
