Isolate electrics or leave bilge pump on stand by.

Isolate electrics or no?

  • Isolate

    Votes: 12 35.3%

  • Don,t isolate.

    Votes: 22 64.7%
  • Total voters
    34
Contest1

Contest1

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My bilge pump float switch recently developed an intermitant short and drained both batteries before I spotted the problem.
When I got Aurora first I always issolated untill I read or heard its best to leave the bilge pump on standby.
The batteries are in recovery, one responding better than its twin.:mad:
Now I wonder whats best practice.
 
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You need to fix or replace the float switch as a first step; it's pointless doing anything else until you know it's working correctly. If you have a bilge pump with a float switch, you might as well leave it connected (via its own dedicated fuse direct from the battery), otherwise what's the point of having it? Personally, I don't have an electric bilge pump and just isolate everything when I leave the boat.

PS How much water do you get in the bilge? And where does it come from?
 
I isolate everything, except the auto bilge pump, so I'm not sure your poll gives enough options. I have a keel-stepped, in-mast furling, mast and the amount of rainwater you get down it can be significant. I am exploring how to block up the mast at deck level to avoid this; however, I would still leave the bilge pump on auto to cope with any unexpected leaks.

Neil
 
a waterwitch is the best bilge pump switch



pvb said:
You need to fix or replace the float switch as a first step; it's pointless doing anything else until you know it's working correctly. If you have a bilge pump with a float switch, you might as well leave it connected (via its own dedicated fuse direct from the battery), otherwise what's the point of having it? Personally, I don't have an electric bilge pump and just isolate everything when I leave the boat.

PS How much water do you get in the bilge? And where does it come from?
Click to expand...
 
We leave the automatic bilge pump turned on, but we are on a marina berth with shore power permanently connected. If you have no way to charge your batteries when the boat is unattended, the decision might be a little different, and depend on how often your boat is visited. I haven't checked the specifications, but I assume that most automatic bilge pumps draw at least an amp, probably more. A small domestic battery bank may well only be able to run the pump for two or three days, so the chances of it saving your boat may be pretty low if it is left unattended for multiple weeks at a time.
 
I'm on a swing, so there's a theoretical risk of a faulty switch 1) Setting fire to the boat 'cos the pump's run dry and caught fire, or 2) Ruining the battery by flattening it completely. The risk of a small leak sinking the boat while I'm away is, to my mind a deal greater than 1 or 2, so I leave the pumps on, but the rest isolated. Buggering a battery is a small price to pay for the boat still being afloat.
 
pvb said:
You need to fix or replace the float switch as a first step; it's pointless doing anything else until you know it's working correctly. If you have a bilge pump with a float switch, you might as well leave it connected (via its own dedicated fuse direct from the battery), otherwise what's the point of having it? Personally, I don't have an electric bilge pump and just isolate everything when I leave the boat.

PS How much water do you get in the bilge? And where does it come from?
Click to expand...

Pump and seperate float switch wired as suggested.
Am tempted to do away with the float switch, replaced just 4 years ago, and just use pump on manual.
Only get water under the engine in a following sea!
Just wonder what others think tho poll is incinclusive so far.
 
Stemar said:
I'm on a swing, so there's a theoretical risk of a faulty switch 1) Setting fire to the boat 'cos the pump's run dry and caught fire, or 2) Ruining the battery by flattening it completely. The risk of a small leak sinking the boat while I'm away is, to my mind a deal greater than 1 or 2, so I leave the pumps on, but the rest isolated. Buggering a battery is a small price to pay for the boat still being afloat.
Click to expand...

I will not disagree with you on that - just pointing out that an automatic bilge pump on a rarely visited boat really does not offer much protection unless you have some significant charging capacity.
 
A fibreglass boat left with all sea connections closed. Where's the water coming from?
I leave all the electrics isolated.
 
NormanS said:
A fibreglass boat left with all sea connections closed. Where's the water coming from?
I leave all the electrics isolated.
Click to expand...

Sea connections and stern glands have been known to leak! I do have to say that I am sceptical about the value of an automatic bilge pump as I said before - it will have no effect on a major leak and will probably run the battery flat within a few days in the event of a minor leak that it can cope with. The only time ours ever does anything useful is when we defrost the fridge - that drains into the bilge!
 
NormanS said:
A fibreglass boat left with all sea connections closed. Where's the water coming from?
I leave all the electrics isolated.
Click to expand...

+1.
Auto bilge pumps are great for open boats, but they shouldn't be needed on a yacht with a self draining cockpit.
If you don't trust the boat to keep the water out, fix it!

There is a danger of turning a minor amount of bilge water into a costly fine for pollution.
 
,
lw395 said:
+1.
Auto bilge pumps are great for open boats, but they shouldn't be needed on a yacht with a self draining cockpit.
If you don't trust the boat to keep the water out, fix it!

There is a danger of turning a minor amount of bilge water into a costly fine for pollution.
Click to expand...

Yes, and as I have posted already on the duplicate of this thread:rolleyes:, a boat beside us in the canal pumped out several hundred gallons of diesel from a leaking tank. His automatic bilge pump did a lot more harm than good.
 
NormanS said:
A fibreglass boat left with all sea connections closed. Where's the water coming from?
I leave all the electrics isolated.
Click to expand...

+1 Also if you have bildge pump how do you know if she is leaking? The pump runs and unless it has a smart counter (if one exisits) how do you know the boat is not leaking??

If the boat does develop a fast leak what are the chances of the battery lasting out till you find out?
 
Can't vote in this poll, as the premise is that you either leave everything turned on, or turn off the bilge pump along with everything else. What about if your battery switches don't disconnect the bilge pump?

In the plans I have for the new boat's electrical system, the switch will cut off most of the consumers, but leave connected things like the bilge pump, chargers, perhaps one day an alarm, etc. It's then not strictly an isolator switch; I'm calling it a "boat occupied" switch.

Pete
 
It would be interesting to know how much water a typical bilge pump could shift before it flattened (for example) 200Ah of battery capacity. I do not believe it would be nearly enough to sink the sort of boat that had 200Ah of battery capacity.

I am assuming of course that when unattended the batteries are not being charged. Mileage may differ if solar, wind or shorepower chargers are in use.
 
jwilson said:
It would be interesting to know how much water a typical bilge pump could shift before it flattened (for example) 200Ah of battery capacity. I do not believe it would be nearly enough to sink the sort of boat that had 200Ah of battery capacity.

I am assuming of course that when unattended the batteries are not being charged. Mileage may differ if solar, wind or shorepower chargers are in use.
Click to expand...

But that all depends on the leak! Almost any bilge pump will cope with a dribble, but no electric bilge pump will win against a serious leak.
 
jwilson said:
It would be interesting to know how much water a typical bilge pump could shift before it flattened (for example) 200Ah of battery capacity. I do not believe it would be nearly enough to sink the sort of boat that had 200Ah of battery capacity.

I am assuming of course that when unattended the batteries are not being charged. Mileage may differ if solar, wind or shorepower chargers are in use.
Click to expand...

You could make a reasonable estimate:
Rule500 draws about 2A when pumping, best case it shifts 500gallon an hour. 200Ah would in theory get you 100hours, so you are looking at 50,000 gallons best case.
that is 250,000 litres i.e. 250 tons!
In reality the 500gph pump will do rather less working against a head etc etc. But even 50 tons would be a problem for a fair sized bateau.

Of course with a wooden boat, you normally find that keeping the bilge dryish means less leaks are in the water.
 
NormanS said:
A fibreglass boat left with all sea connections closed. Where's the water coming from?
Click to expand...

In the case of my Sadler 29 it's RAIN WATER. I'm on a drying mooring, and IF it rains heavily and IF the boat happens to sit slightly nose-down then water gets into the engine bilge via the liferaft bin in the cockpit sole.

Before I fitted an automatic bilge pump (wired directly to a domestic battery) the engine bilge would fill (not good for submerged bits of engine and gearbox) and even sometimes spill over into cabin. I have even suffered water in the gearbox oil because of this.

My float switch DID fail 'on' recently, and not surprisingly result was one flat battery......but I prefer that slight risk to the alternative.

Incidentally, I have read that the WATERWITCH is unreliable in clean fresh water, as it would be in my case (as might well be expected due to conductivity).
 
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