Originally Posted by ianhef
1) Can I keep the batteries wired up to the services when charging
or would I have to disconnect everything before charging
2) Are there any problems with using this quick fix, temporary solution?
1) It depends on the battery
charger. The main risk is to supply to the DC load a voltage higher than it can support. I will consider anything above 15 Vdc risky. Also if the DC load is bigger than the current
the charger can supply then there is a risk of under-voltage (burn out, battery not getting charged). Find out by reading the documentation
provided by the manufacturer if their charger suits your requirement.
2) This is not a quick fix. Most boats in a marina are connected to the shore supply by the use of plugable flexible cord (s) and very few are permanently connected to the shore by fixed wiring
(requires the use of tools to disconnect). Australian Standard 3000 sets requirement for permanent wiring and AS 3004 did cover the wiring of electrical
installations in marinas
and pleasure craft at mains voltage. Due to the constant improvement of these standards, the use of licensed electricians, the fact that some requirements are more suitable to larger craft, make for the lack of popularity of 240 VAC permanent wiring in Australian boats. In Rome do like the Romans, in Australia
do like the Australians and disregard other countries as most are stuck with electrical problems they have created.
Originally Posted by LiFeTech Energy
Speaking in my capacity as an electrical engineer
and licensed electrical contractor/electrical supervisor there is no problem using an extension cord from the dock
to power a battery charger for topping up your batteries so long as a few simple rules are followed.
1) Always use a power board with an ELCB (earth leakage circuit breaker). If there is any current leakage to earth the breaker will trip so you have protection.
2) All mains powered electrical appliances
which are safe to use in Australia
(as deemed safe by the state electrical authorities) will have a C-tick and electrical safety
approval number marked on them. Only use appliances
which have these marks.
3) Very few battery chargers made these days use the old traditional heavy transformers. They are all switch mode devices and if there is any leakage the ELCB will trip out.
I agree in general with the above, with the following recommendations: see if you can purchase
a battery charger that is double insulated. A double insulated battery charger does not require earthing and for this reason does not have an earth pin, just two pins for the active and neutral and show the mark of a square inside an other square. An ELCB will protect you but not the boat. Most will trip at 30mA which is too much undesirable current leakage for the health
of a boat. Beware of switch mode devices. Some are so poorly built that they require an earthing to bleed the RF away.
Originally Posted by ianhef
Only worry now is that when I look around I see every boat has a power cable of some sort and I'd be pretty sure not all have proper onboard systems, as one of the posters asked above, is there anyway to check the dock is hot? (instead of waiting for a prop to drop off!)
Quiet simple, minimize connection with the ground, do not be a path for other boat poor earthing. An anchor
chain, a permanently connected fresh water
hose can be a path and if you require the use of an earthed appliance, insulate it from the metallic part of the boat by the use of a suitable insulating material.