On-board charger

[davidej]

We have just got the electricity bill for the first winter in the yard for our s/h Bene. This was much larger than I expected, probably because we left the onboard charger running 24/7.
The charger is a 'Dolphin' (French, of course) and the instructions dont say whether it drops down to a low charging rate. Is it possible that this is doing more harm than good, leaving it on for such an extended period
On my previous boat, which did not have such luxuries, I have left a trickle-charger (putting out around 350mA) on for about four hours a day controlled by a timer. Does this sound a more sensible arangement?
Thanks.

 

[lw395]

If there is no load on the batteries, then 350mA one sixth of the time should be plenty.
How many kWh are you being charged for?
I doubt any charger can shove more than a few amps into a full battery, without drying it, so more than say 1kWh/week would have me thinking someone had plugged their heater in?
Can you borrow one of those plug in kwh meters (15 quid maplins type) to check your chargers draw?

 

[CSFenwick]

Doubt it's the charger - unless it's faulty. I have a Merlin charger with Dolphin innards and once on float it draws next to nothing. A 100KWH power card (£12.50 at Conwy marina) lasts months over the summer and that includes us on the boat a good number of Friday evenings.