Safe to Leave Dead Batteries on Board for the Winter?

[P12nash]

My house battery bank (2 sportsman dc8d FLA batteries) suffered a catastrophic drain when my bilge pump float switch was found stuck in the on position after a week and a half away from the boat. When I got to the boat they were sitting at 7.9 volts... and the pump was still humming. I charged them back up but they no longer maintain a charge. 24 hours after pulling the charger the voltage drops below 11with no draw.

I know I’ll be swapping the batteries out in the spring, but would ideally like to do it when I can bring the boat to the dock so I don’t have to haul the batteries down and then the new ones up a ladder. Is there any risk that dead batteries will freeze on board in the New England winter without a full charge and cause a bigger mess?

 

[Captain Larry-DH]

Dead batteries will freeze and crack the case, and can leak acid. Fully charged batteries resist freezing down to sub-zero temps

 

[dlochner]

Yes. If they are in a non leaking battery box the mess will be contained.

 

[leo310]

you need to remove the batteries as they will freeze and one thing you don't want is to deal with is cleaning acid.

 

[P12nash]

That’s what I thought. Was hoping to make it easy on myself in the spring and also save a little on recycling/core costs. Such is life. I’ll pull them this weekend and recycle

 

[Benny17441]

My take on that frequently occurring problem is to shut off the bilge pump whenever I leave the boat. It has been demonstrated that bilge pumps are a convenience item rather than a safety one. Safety is obtained by periodically checking the thru hulls, valves, hoses, clamps and shutting off fixtures like the Head whose water intake relies on an internal seal which is not practical to inspect. When I come aboard the boat the first thing I do is turn the bilge pump on and I will gauge by the run time if there is an increase in a water leak somewhere that requires my attention. A bilge pump in operation all the time will mask any leaks by discharging water without our knowledge. My first boats came from factories without automatic bilge pumps, the designers knew what they were doing. The automatic bilge pump is just a selling feature, one that led to the proliferation of float switches that have killed a good number of battery banks. The best argument that I have heard for powering bilge pumps 24/7 is "If they can save the boat or not; what do I have to loose" and my answer is "the battery bank". Peace og mind comes from frequent inspections and maintenance. Most boats that take on water and damage the cabin deck floor usually lacked basic maintenance. Sailors need to do what gives them the best peace of mind, I'm just offering as an alternative, the way I do it.

 

[rgranger]

And... won't you need living batteries to keep your pump operational over the winter?

 

[Don S/V ILLusion]

Any marina I’ve ever been at up north routinely walked their docks in winter to ensure lines were good, ice was cleared and bilge pumps weren’t running continuously. They do the same thing (absent the ice issue) here in Florida all Summer.
Just because it may not keep up with a catastrophic leak doesn’t mean it’s okay to shut it/them off in winter.

 

[Captain Larry-DH]

Battery freeze math Battery Freezing Math

 

[Hello Below]

My take on that frequently occurring problem is to shut off the bilge pump whenever I leave the boat.

I wonder if that would have any affect on an insurance claim?

 

[Captain Larry-DH]

And... won't you need living batteries to keep your pump operational over the winter?

Maybe in Charleston, but not in New England. If there’s any bilge water it’s likely to freeze solid. After I winterize my engine I suck any residual water out of the bilge with a shop vac, then add a gallon of -50 antifreeze to the bilge and run the bilge pump one more time. Then I vacuum any residual antifreeze out too.

 

[berner73]

My take on that frequently occurring problem is to shut off the bilge pump whenever I leave the boat. It has been demonstrated that bilge pumps are a convenience item rather than a safety one. Safety is obtained by periodically checking the thru hulls, valves, hoses, clamps and shutting off fixtures like the Head whose water intake relies on an internal seal which is not practical to inspect. When I come aboard the boat the first thing I do is turn the bilge pump on and I will gauge by the run time if there is an increase in a water leak somewhere that requires my attention. A bilge pump in operation all the time will mask any leaks by discharging water without our knowledge. My first boats came from factories without automatic bilge pumps, the designers knew what they were doing. The automatic bilge pump is just a selling feature, one that led to the proliferation of float switches that have killed a good number of battery banks. The best argument that I have heard for powering bilge pumps 24/7 is "If they can save the boat or not; what do I have to loose" and my answer is "the battery bank". Peace og mind comes from frequent inspections and maintenance. Most boats that take on water and damage the cabin deck floor usually lacked basic maintenance. Sailors need to do what gives them the best peace of mind, I'm just offering as an alternative, the way I do it.

At the risk of further derailing this thread, I have always shared a similar mindset to Benny's post but I'd really like to hear other perspectives. When we kept the boat in a slip with shore power, we always left the automatic bilge pump connected. Now that we're on a mooring, I just don't see the point. We can't carry the battery capacity to run a bilge pump under load 24/7. Typically the boat will sit idle during the work week, if an issue arose, it would drain the batteries long before any corrective action could be taken. It's the primary reason why I'm so OCD about finding any water in our bilge (we're deck stepped with a PSS shaft seal). I've estimated that any failure to the on board systems could be contained by the volume of the bilge (fresh water, diesel, etc). Anything outside of that and we're sunk one way or the other. Why risk a false trigger of the bilge pump resulting in dead batteries? I'm really curious to hear what others have to say about this.

 

[P12nash]

At the risk of further derailing this thread, I have always shared a similar mindset to Benny's post but I'd really like to hear other perspectives. When we kept the boat in a slip with shore power, we always left the automatic bilge pump connected. Now that we're on a mooring, I just don't see the point. We can't carry the battery capacity to run a bilge pump under load 24/7. Typically the boat will sit idle during the work week, if an issue arose, it would drain the batteries long before any corrective action could be taken. It's the primary reason why I'm so OCD about finding any water in our bilge (we're deck stepped with a PSS shaft seal). I've estimated that any failure to the on board systems could be contained by the volume of the bilge (fresh water, diesel, etc). Anything outside of that and we're sunk one way or the other. Why risk a false trigger of the bilge pump resulting in dead batteries? I'm really curious to hear what others have to say about this.

When I figured out the bilge pump had killed my batteries I pulled the fuse for the pump. Ended up not needing to reinstall it for the remainder of the season. I do leave all of my thru hulls closed when I leave the boat and after a few weeks of no water in the bilge I became pretty confident without the pump connected.

Based on Hello Below’s comment above I may shoot my insurance agent an email to see if he has any thoughts on liability if the pump is turned off and something does happen.

 

[splax]

That’s what I thought. Was hoping to make it easy on myself in the spring and also save a little on recycling/core costs. Such is life. I’ll pull them this weekend and recycle

save them for the core charge on the new ones

 

[P12nash]

save them for the core charge on the new ones

Unfortunately, I just don’t have a good place to store two large batteries all winter which is why I was wishfully thinking there might be a way to keep them in the boat

 

[Tedd]

After you remove them, you might try putting them on a battery tender over the winter. I've had good luck with overly-discharged batteries recovering on a tender.

 

[Justin_NSA]

Unfortunately, I just don’t have a good place to store two large batteries all winter which is why I was wishfully thinking there might be a way to keep them in the boat

Do you have any metal recycling facilities nearby? They will pay about what the core charge would be. About $10 I think.

 

[Scott B]

Unfortunately, I just don’t have a good place to store two large batteries all winter which is why I was wishfully thinking there might be a way to keep them in the boat

Any battery retailer will take them for core charge. Any Interstate dealer close by? Your not going to get much now or later so easier to just get rid of them now.

 

[dLj]

At the risk of further derailing this thread, I have always shared a similar mindset to Benny's post but I'd really like to hear other perspectives. When we kept the boat in a slip with shore power, we always left the automatic bilge pump connected. Now that we're on a mooring, I just don't see the point. We can't carry the battery capacity to run a bilge pump under load 24/7. Typically the boat will sit idle during the work week, if an issue arose, it would drain the batteries long before any corrective action could be taken. It's the primary reason why I'm so OCD about finding any water in our bilge (we're deck stepped with a PSS shaft seal). I've estimated that any failure to the on board systems could be contained by the volume of the bilge (fresh water, diesel, etc). Anything outside of that and we're sunk one way or the other. Why risk a false trigger of the bilge pump resulting in dead batteries? I'm really curious to hear what others have to say about this.

The last blue water boat I owned did not even have an automatic bilge pump. It only had two manual bilge pumps, one accessed from inside the cabin and one accessed from the cockpit. I moored the boat during the summer in the ocean - well, a bay connected to the ocean - for years. In the winter it also stayed in the water, but in a port. I never had a problem. That boat did not have a PSS shaft seal, it had a standard packing gland. It did not leak when sitting idle. There were no other leaks in the boat. It was what I call a dry boat.

My question to you is, why do you feel you need the battery capacity to run a bilge pump 24/7 unless you have a leak in your boat? I'm not understanding this concern? If you have a dry boat, why wouldn't you just leave your automatic bilge pump on? I'd run one battery to it, if I got onboard my boat and that battery was dead, or low, I'd know I had a problem (obviously if my boat wasn't sunk, then I'd not need to check by getting onboard). I'm not following the logic. If I have a dry boat, why wouldn't I leave an automatic bilge pump on? It's not going to turn on so won't drain my battery. If it does have to turn on, and sufficiently often to cause my battery to discharge, then I've got an early detection system. If the battery dies, and my boat sinks, well, it wouldn't have mattered in either case, with or without the automatic bilge pump. I'm not following the logic here. Help me out.

Obviously, I feel you can survive without an automatic bilge pump, but if you have one, why wouldn't you use it?

dj

 

[berner73]

My question to you is, why do you feel you need the battery capacity to run a bilge pump 24/7 unless you have a leak in your boat?

And therein lies the question - "unless you have a leak in your boat". I 'think' we're in agreement but not sure. I should clarify that when away from the boat, the only reason we would need an automatic bilge pump is to address an unexpected ingress of water. We keep a dry boat, dusty bilge and close all seacocks before leaving. My early detection system after being away from the boat is to check the dusty bilge for signs of water, not a dead battery. Why would one risk running down a battery due to a stuck float switch for the same purpose (similar to the OP's situation)? I don't need an always on automatic bilge pump for the current state, it would be for insurance against an unexpected and unattended event. Stuff happens, things fail and batteries run out of juice. I can understand the purpose if you had a 'wet' boat, but I struggle with the logic for a 'dry' one. Maybe it's an insurance liability as mentioned above?

To Benny's point - "The best argument that I have heard for powering bilge pumps 24/7 is "If they can save the boat or not; what do I have to loose" and my answer is "the battery bank".