Stupidity: Forgot to shut off the battery isolator.

[Baggywrinkle]

I forgot to shut off the battery isolator when we last left the boat - How long do I have before my batteries are toast?

Batteries were fully charged and around 200Ah total, nothing was turned on but forgot to remove the isolator key from the switch.

Boat is 5 hours away in the Med and I have the only key in my trouser pocket.

Dilemma is - do I drive down there at the weekend as there is some stuff I could also do at the same time or will it survive until Christmas?

 

[David2452]

If your electrical system is sound and nothing is switchd on I see no cause for alarm, certainly not for the three weeks or so until Christmas anyway.

 

[sigmasailor]

If you are 100% sure nothing is draining the batteries it won't make any difference with the isolation switch either on or off. Sooo, the big question is: are you really 100% sure no power is used?

 

[Nina Lucia]

I leave my main batterie on all the time just in the case auto bilge pump need to kick in...
I do have small Rutland wind generator...

 

[VicS]

I leave my main batterie on all the time just in the case auto bilge pump need to kick in...
I do have small Rutland wind generator...

The OP should have no cause for concern if the electrical system is sound and there really is nothing switched on

But for you it would be sensible to connect your Rutland and bilge pump to an "always on" busbar so that you can switch the main isolator off

 

[prv]

nothing was turned on but forgot to remove the isolator key from the switch.

If there's truly nothing turned on, then it makes no difference from a consumption point of view whether the master switch is on or off. You don't disconnect the battery on your car whenever you park, do you?

I don't even have an isolator on my boat. I'm happy that the single cable from battery to main panel is sound - and after all, if I did have an isolator there'd still be a live cable to it so no real difference. At the panel, every circuit has its own switch and fuse, so when I leave I just run my finger down the "off" side of the column of switches and everything is just as isolated as if I had one big switch.

Pete

 

[Simondjuk]

when I leave I just run my finger down the "off" side of the column of switches and everything is just as isolated as if I had one big switch.

Except the engine?

 

[prv]

Except the engine?

That's true, of course. But again, no different to a car. The batteries are right next to the engine, so no long wire runs, and the positive terminals (starter and alternator) are well shrouded with rubber covers so minimal risk of accidental shorting. If I'm actually working on those components themselves, I disconnect at the battery end, which is fairly straightforward.

The idea was to minimise wire runs and number of connections for efficient charging, with a secondary aim of making starting the engine, turning on the radio, etc as simple as possible. When I'm not single-handed I'm usually with one other person, generally inexperienced. I don't really want to be concentrating on explaining how to find and operate the "funny red key thing under the chart table" or whatever.

Pete

 

[Baggywrinkle]

Thanks for the reassuring posts. There should be no current drain, but as the boat is new to me, I don't yet know exactly what is connected and how - original wiring diagrams show nothing drawing current. Unfortunately I only checked that the isolator was really an isolator, and then forgot to use it.

Then there are the modifications by the previous owner .....

 

[Robin]

Beware of things like radio/cd players that have built in clocks, often wired anyway to bypass the battery switch to avoid the need to re-program every time. We had a gas alarm that we found drew 0.3A constantly, not much on it's own but that is 8ah per day or 56ah per week so a 200Ah battery would be down to 50% in 2 weeks and dead soon after. In our case the alarm was only 'on' when the battery switches were on and anyway we were plugged into shorepower when not on board.

 

[25931]

I forgot to shut off the battery isolator when we last left the boat - How long do I have before my batteries are toast?

Batteries were fully charged and around 200Ah total, nothing was turned on but forgot to remove the isolator key from the switch.

Boat is 5 hours away in the Med and I have the only key in my trouser pocket.

Dilemma is - do I drive down there at the weekend as there is some stuff I could also do at the same time or will it survive until Christmas?

A small solar panel should prevent the batteries going completely flat and insurance cover should be some protection in the event os a short.

 

[ghostlymoron]

You should always have your bilge pump on a direct circuit. The idea being that the pump will always work til the battery is flat and THEN your boat will fill up and sink!

 

[Ric]

I forgot to shut off the battery isolator when we last left the boat - How long do I have before my batteries are toast?

Batteries were fully charged and around 200Ah total, nothing was turned on but forgot to remove the isolator key from the switch.

Boat is 5 hours away in the Med and I have the only key in my trouser pocket.

Dilemma is - do I drive down there at the weekend as there is some stuff I could also do at the same time or will it survive until Christmas?

Well it will be a lot cheaper to replace 200Ah of batteries than drive ten hours in a car!

 

[johnalison]

I can't help with the electrical conundrum but this sort is situation is one reason why we leave a spare key with the marina office. The local engineers can then deal with routine requests and there should be someone who could fix a problem like the OP's.

The other reason is of course that I sometimes forget to take my keys.

 

[Baggywrinkle]

I can't help with the electrical conundrum but this sort is situation is one reason why we leave a spare key with the marina office. The local engineers can then deal with routine requests and there should be someone who could fix a problem like the OP's.

The other reason is of course that I sometimes forget to take my keys.

I'd love to leave a spare key with the marina ... but I've only got one and was trying to get it duplicated (alas a hopeless task as no-one seems to have the correct blank).

Looks like I need to replace the companionway lock or cylinder - oh the joys of living miles from the boat.

The cheapest option would be to post my one remaining key to the marina with a letter asking them to turn off the isolator. I now need to replace the lock anyway so no wories if it 'goes missing'.