One for the experts in electro-chemistry ?
My Pearl hasn't been out for 6 months, but a couple of days ago I decided it was high time for a run out. Came to start the engine, ignition light on, pull starter, light goes out and absolutely nothing from the starter motor. Further check shows battery voltage collapsing to near zero when a start attempted. The battery is a traditional style rubber cased one with exposed lead links, and probably 4 years old.
Now I know what you are thinking - this idiot has just left it and allowed his battery to go flat. However, the whole of the 6 months it has been dutifully connected to a stabilised power supply set at 6.9 volts i.e. a normal float charge setting. Nothing "smart" about it.
With nothing to lose, I gave it a 24 hour charge at 10 amps (tapering down to 3 amps). It now seems OK, with terminal voltage of over 6 volts (all individual cells very similar voltage) and only dropping to about 5 volts when cranking.
Rather than putting off the inevitable, I have ordered a new battery anyway. But I'm mighty curious to know what's going on. Does prolonged float charging cause a high resistance film to build up on the plates ? Unfortunately my hygrometer disappeared years ago so I don't know what the SG is up to.
My Pearl hasn't been out for 6 months, but a couple of days ago I decided it was high time for a run out. Came to start the engine, ignition light on, pull starter, light goes out and absolutely nothing from the starter motor. Further check shows battery voltage collapsing to near zero when a start attempted. The battery is a traditional style rubber cased one with exposed lead links, and probably 4 years old.
Now I know what you are thinking - this idiot has just left it and allowed his battery to go flat. However, the whole of the 6 months it has been dutifully connected to a stabilised power supply set at 6.9 volts i.e. a normal float charge setting. Nothing "smart" about it.
With nothing to lose, I gave it a 24 hour charge at 10 amps (tapering down to 3 amps). It now seems OK, with terminal voltage of over 6 volts (all individual cells very similar voltage) and only dropping to about 5 volts when cranking.
Rather than putting off the inevitable, I have ordered a new battery anyway. But I'm mighty curious to know what's going on. Does prolonged float charging cause a high resistance film to build up on the plates ? Unfortunately my hygrometer disappeared years ago so I don't know what the SG is up to.