Installing a bilge pump in Mac 25
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johnnyonspot
- First Officer
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Installing a bilge pump in Mac 25
Hey friends, I will be slipping my Mac 25 this summer and believe it prudent to install a bilge pump. I was thinking I could run the outlet to the cockpit drain line using a T-fitting. I would need some way to ensure water in the cockpit does not drain down through the pump into the bilge, however. I suppose a check valve of some type could be used for this. My questions are: Has anyone done this? If so, how? Where should the bilge pump be placed, i.e., where is the lowest point in the bilge? Any ideas on a check valve I might use that would work well in this application? Does anyone have any reservations about running out the cockpit drain line? (I want to avoid having to do a new thru-hull). Any other ideas or reservations about this?
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johnnyonspot
- First Officer
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- Joined: Thu Oct 06, 2005 9:19 pm
- Location: Elk River, MN.
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johnnyonspot
- First Officer
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- Joined: Thu Oct 06, 2005 9:19 pm
- Location: Elk River, MN.
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Frank C
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johnnyonspot
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Right. That's why I was looking at a solar charger, but I guess I would need more than a trickle charger to maintain the battery in the event of incoming water. Though there are some solar chargers that charge fairly well. I would have to get a switch to shut the charger off at full charge, though, or a charger with that feature built in. I don't want to spend a lot of ching on this if I can avoid, but will bite the bullet in order to be sure all is well.
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Catigale
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A Rule 500 gph bilge pump has a current draw of about 2.5amps...thats an electrical load of 30 Watts give or take.
A 60W solar panel would probably just keep the battery topped off if it was running a lot - you have to derate the panel output by 50% for both angle and cloud losses. It would be fine for intermittent pumpout for a slow leak.
A 60W solar panel would probably just keep the battery topped off if it was running a lot - you have to derate the panel output by 50% for both angle and cloud losses. It would be fine for intermittent pumpout for a slow leak.
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walt
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Solar panels work well if your power use has only a low duty cycle. A 60 watt panel is awful big... I have a 20 watt panel (with a charge controller) and its intention is mostly to have have my 230 amp hour battery set all charged for when I use the boat on average one day per week. My 20 watt panel is just laying flat on the deck (there just arent a whole of good places to put one on a boat..) and I may get only about 3 to 4 amp hours out of it per day and that would let your pump run for a an hour or two per day. But that would mean your batteries would not be charged when you went to use the boat on the weekend and a 20 watt panel wont hardly keep the light on if you had to rely on it for "real time" power.
Seems if your pump is running an hour or two per day, you would have some other fairly major issues you needed to take care of.
Seems if your pump is running an hour or two per day, you would have some other fairly major issues you needed to take care of.
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johnnyonspot
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Right. I do not think I have any leaks, slow, fast or otherwise. So maybe I should just get the small panel and live with it, and if the boat somehow floods, deal with that.
Would a solar powered trickle charger be sufficient to top off the battery over a period of one week between uses, or would I need a charger with more output to do that?
Would a solar powered trickle charger be sufficient to top off the battery over a period of one week between uses, or would I need a charger with more output to do that?
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walt
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- Location: Colorado "Sea Eagle" 1990 26S
If solar is your only power source, I think you probably need more than a trickle charger. Here is my example (Im fairly conservative on my power usage)
Per week, my power usage might be:(this is basically one day per week of using the boat)
Stereo 4 amps * 6 hours = 24 amp hours (I have two almost teenage boys - woops forget to add in the laptop which gets used to watch DVD)
depth guage .25 amp * 6 hours = 2 amp hours
Other insturments 2 amp hours
lights 3 hours * 1 amp = 3 amp hours
Pump .4 hours *2.5 amp = 1 amp hours
Note - pump assumes its on for only 24 minutes per week
Total consumption = 32 amp hours
Over a week, lets say I get 6 hours of good sunlight per day (42 hours per week) and my derated solar panel output is .04 amps per panel peak rated watt (ballpark, this would be about .8 amps for a 20 watt panel - all sorts of assumptions could vary this but its probably not that far off).
amp hours consumed = amp hours generated
32 amp hours = 42 hours * PPP * .04 amps/PPP
PPP = 19.04 watts - ie, I need a about a 20 watt peak power panel
Note also that for a panel this size, you should get a charge controller. Since your in a cold climate, Id make sure the charge controller had temperature sensing. The battery voltage is a fair amount higher when it gets very cold and if the charge controller is mounted fairly close the battery, it will compenate for the temp and keep the battery fully charged during the winter.
Ive had this sort of set up on a boat stored outside near a lake which gets 3 foot of ice during the winter and just leave the battery in the boat. Havnt had any problems for a few years of doing this.
Note also that if you run your outboard, you can also suppliment your battery charge. My 8 hp is supposed to put out 60 watts which I assume is about 5 amp. So every hour I run the outbourd, I would get an additional 5 amp hours. You would not want to charge the battery full time with 5 amps but likely for as much as a motor gets used (assuming your more likely to be sailing than motoring) your probably not at much risk for any damage to the batteries.
Per week, my power usage might be:(this is basically one day per week of using the boat)
Stereo 4 amps * 6 hours = 24 amp hours (I have two almost teenage boys - woops forget to add in the laptop which gets used to watch DVD)
depth guage .25 amp * 6 hours = 2 amp hours
Other insturments 2 amp hours
lights 3 hours * 1 amp = 3 amp hours
Pump .4 hours *2.5 amp = 1 amp hours
Note - pump assumes its on for only 24 minutes per week
Total consumption = 32 amp hours
Over a week, lets say I get 6 hours of good sunlight per day (42 hours per week) and my derated solar panel output is .04 amps per panel peak rated watt (ballpark, this would be about .8 amps for a 20 watt panel - all sorts of assumptions could vary this but its probably not that far off).
amp hours consumed = amp hours generated
32 amp hours = 42 hours * PPP * .04 amps/PPP
PPP = 19.04 watts - ie, I need a about a 20 watt peak power panel
Note also that for a panel this size, you should get a charge controller. Since your in a cold climate, Id make sure the charge controller had temperature sensing. The battery voltage is a fair amount higher when it gets very cold and if the charge controller is mounted fairly close the battery, it will compenate for the temp and keep the battery fully charged during the winter.
Ive had this sort of set up on a boat stored outside near a lake which gets 3 foot of ice during the winter and just leave the battery in the boat. Havnt had any problems for a few years of doing this.
Note also that if you run your outboard, you can also suppliment your battery charge. My 8 hp is supposed to put out 60 watts which I assume is about 5 amp. So every hour I run the outbourd, I would get an additional 5 amp hours. You would not want to charge the battery full time with 5 amps but likely for as much as a motor gets used (assuming your more likely to be sailing than motoring) your probably not at much risk for any damage to the batteries.
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johnnyonspot
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My usage, right now, is pretty bare bones. Stereo, tiller pilot... probably add a VHF at some point. Also, I take the battery out during winter and store it in a garage where I will periodically top it off.
If I just get a small solar trickle charger, do I need a controller to keep it from being overcharged?
If I just get a small solar trickle charger, do I need a controller to keep it from being overcharged?
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walt
- First Officer
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- Joined: Mon Feb 05, 2007 9:05 am
- Location: Colorado "Sea Eagle" 1990 26S
Your probably OK, read the section here on "when do panels require regulation"
http://www.westmarine.com/webapp/wcs/st ... panels.htm
I dont understand why you want a solar trickle charger however. When you are using the boat in the summer, it likely wont supply the power you need (you have to do a current consumption budget to see what you need similar to the example I gave) and in the winter, if your battery is in the garage, you will need to maintain the charge with some other method..
One other somewhat messy subject with batteries regardless of how they are charged.. You normally dont want to let the charge of a deep cycle battery go below about 50%. So in my case of having 230 amp hours, I have 115 amp hours to use - gives me some reserve over my normal use. On occasion (like a 4 day trip Im planning), I may let the batteries go below this as they are cheap batteries and in the overall "cost" scheme of things, occasionally drawing them down below 50% is not going to matter. But you probably would not want to do this on a regular basis (I say probaby because it may be cheaper to wear batteries out faster by doing deep discharging than to buy all the stuff to keep them charged above 50%). The cheapest way to monitor battery charge is by measuring the voltage but this also has all sorts of inacuracies - but I think its adequate in the overall scheme of things. So you may also have to consider some way to monitor the voltage of your batteries.
http://www.westmarine.com/webapp/wcs/st ... panels.htm
I dont understand why you want a solar trickle charger however. When you are using the boat in the summer, it likely wont supply the power you need (you have to do a current consumption budget to see what you need similar to the example I gave) and in the winter, if your battery is in the garage, you will need to maintain the charge with some other method..
One other somewhat messy subject with batteries regardless of how they are charged.. You normally dont want to let the charge of a deep cycle battery go below about 50%. So in my case of having 230 amp hours, I have 115 amp hours to use - gives me some reserve over my normal use. On occasion (like a 4 day trip Im planning), I may let the batteries go below this as they are cheap batteries and in the overall "cost" scheme of things, occasionally drawing them down below 50% is not going to matter. But you probably would not want to do this on a regular basis (I say probaby because it may be cheaper to wear batteries out faster by doing deep discharging than to buy all the stuff to keep them charged above 50%). The cheapest way to monitor battery charge is by measuring the voltage but this also has all sorts of inacuracies - but I think its adequate in the overall scheme of things. So you may also have to consider some way to monitor the voltage of your batteries.
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Frank C
Back to your original premise ... the bilge pump. Most Mac owners take the view that Roger didn't drill any holes below the waterline, they're not going to either. Without an underwater fitting to fail, how can the boat take water? If it's taking water topsides, that should be very slow and easy to find and fix. In the unlikely event a split hull is admitting water, then your bilge pump, battery and solar charger ...
all 3 will be peeing upstream.
all 3 will be peeing upstream.