Good sailing today. 10-15. Good day to learn more about my compac. I tested the battery on my mini-multimeter before leaving as I have used it "some" after charging a few weeks ago. After a few hours I started back and noticed a slower headway under power. Soon the prop was turning like molasses in winter.
My natural assumption was I was out of voltage. Was able to get back in and brought the battery home to charge. It is a 12V deep cycle marine battery. To my surprise it still read fully charged on the meter. The battery is mounted under the entrance to the cabin so it sits about 10-12 feet away. The extension guage wire is appropriate and is mounted with a female plug unit under the seat. The motor is a new MinnKota 50# thrust. Any thoughts of what the issue might be.
We need more info (please :)) What was the exact voltage your battery was showing. Any corrosion on any contacts- did you wiggle them? Now that the battery charger has had its way with your battery- its there any difference with the prop speed? Finally- if you warm up the minokota motor to 70 degrees or so- is there any difference in the speed?
You don't need the volts as much as the amp-hours.
What is the amp consumption of the electric motor?
What is the amp hour capacity of the battery.
Bare in mind that the power made in a wet cell battery
is chemical which is cut in half at freezing. So at
40 or 50 or 60 deg F. that effects the output.
I believe electric anything is no good unless it's plugged in.
Battery power is never renewable due to ENTROPIC tendency's.
On the old Pig Boats and later Fleet Boats of WWII, from center line down was all battery.
So much so that just a few few ton of water in the ballast tanks pulled them under.
Check the off topics for electrical posts.
skip.
Corinthian -
Skip is right... and so is Newt... The power of the motor and the time during which it can be sustained depend on a) the draw (amperage) of the motor (do you know its amperage?), b) the amp hour capacity of the battery (it should be marked on the battery?), and c) its charged status. Although there are more accurate ways of doing it, the status of the charge is usually assessed by determining the voltage between the battery poles: in an 12V acid-lead battery a reading of 12.7V means fully charged and 11.9V means totally drained (i.e., only 0.8 V difference). What was the actual reading in your mini-multimeter?
From the amperage of the motor, the Amp-hr of the battery and its charged status you should be able to approx. determined how much time of full-power you could expect.
Also, loose contacts at the battery or the motor may cause a reduction in the power supplied by the battery to the motor.
J.
Big Draw, Big wire.
Interesting enough electrons flow on the easiest path they can find.
That means electrons flow on the outside of every conductor used in the make-up of the wire.
Electrons never flow 'through' a wire, just on top of a wire.
So you need a lot of surface for these guys to skate on.
Perfectly clean contacts are required and hard to achieve on boats in water.
Condensation is a bugger. Worst in salt air and water. Not so bad in fresh water.
Each cell in the battery can make as much as 2.2 volts, but never do. Volts is
just the push used to move electrons over the wire, and through the resistance
and that could be the electric motor and switch gear.
The cool thing about electric motors is they produce full torque at anything above
zero rpms. That's how I use to burn off the rubber tires on my 5000 lb capacity forklift
that was fitted with a 1200 lb wet cell battery pack. That pack lasted almost a whole 10 hour day.
skip.
I use a 35# thrust with a 24M marine battery. so far it's been enough but I don't run it more than 30mins out and the same back (if at all) and I never run it more than 2/3 throttle.
I think a 50# motor isn't too large but it is going to eat what juice you have faster. Also the boat suffers much more windage than you might be accustomed to (I certainly was) and the motor will be working that much harder.
Unless you're running the motor hard for a 'long' time then I would doubt the efficacity of the battery (unless it's new).
You could try running the motor lower in the water too. Also disconnect everything else except the motor from the battery and try that.
Corinthian,
I was able to consult the owner's manual of a Minn Kota Endura 50 42" Trolling Motor (if not the same it should not be too different than the one you have) and this is what it says:
"These motors will operate with any deep cycle marine 12 volt battery. For best results, use a deep cycle Minn Kota marine battery with at least a 105 ampere hour rating. As a general on the water estimate, your 12 volt motor will draw one ampere per hour for each pound of thrust produced when the motor is running on high."
Usually a 12 V "Group 24" deep cycle battery (possible not too different than the one you describe as "M24"?) would be rated at 70-85 Amp hours. In such case, an optimistic estimate is that with a fully charged battery you would have enough "juice" for approximately 1.5 hour at full power.
J.
Corinthian,
There are two things to keep in mind.
1. Drawing a lead acid battery below 50% charge severely shortens its lifespan.
2. Storing a lead acid battery over the winter without ever charging it can kill it. Gels and AGM are less suseptible than "wet" batteries. Its worse if the battery is subject to the cold (certain to kill it) or is left sitting on concrete (basement floor or garage floor).
Overcharging can also kill a battery. A good charger helps but don't leave on any charger indefinitely.
Battery life varies from 1-2 years for an abused battery to as much as 10 years for a very well cared for battery.
You'll get the most life out of a battery if you don't draw it down below 1/2 charge and if you start recharging as soon after you draw it down as you can and bring it back to full charge. Try not to let it go more than 2-4 hours and not to leave it flat overnight. If you store the battery for any length of time, recharge every 2-4 weeks. Gels and AGM can go much longer between charges when stored due to lower self discharge and much less tendency to sulfate. Gels are very sensitive to being overcharged.
What kills the battery in these cases is called "sulfation" which is chemical precipitation of lead sulfate. Chemical recipitation is the disolved lead sulfate turning into a solid and falling to the bottom of the battery where it will never be disolved again. The more sulfation, the less capacity (amp-hours from full charge to discharge). Eventually enough lead sulfate can end up on the bottom to short the battery and its shot.
Nigel Calder beats this subject to death in his book "Boatowner's Mechanical and Electrical Manual". Nigel will tell you way more than anyone needs to know about their boat battery and electrical system but it is a great book.
Curtis
ps - when my group 27 wet cell gave it up I replaced it with an AGM. An 8D (at 160 lbs). Took a little work getting it in there. The solar panel is good for keeping a float charge.
(http://www.faster-light.net/remote-access/image/20050504-battery-01.jpg)
See http://www.faster-light.net/remote-access/projects_E_C.html#2 (http://www.faster-light.net/remote-access/projects_E_C.html#2) for other details.
Is the wiring between the battery and the motor new? or is it the wire off the motor that attaches directly to the motor?
You said that the wire size is appropriate? Tell me more. What is the Amp rating on the motor and what is the wire size?
The reason I ask is that for starting a diesel on a larger boat, the starting circuit was "appropriate" but upgraded the wire sizes a couple of sizes and it made all the difference.
Also if the wiring is original, is there heat tubing on the ends? I have found wire that is rotting up to a
foot inside the insulation because the terminal was put on and then electrical tape used... best to use heat sink tubing.
thanks
Bob
In addition to everything else mentioned.....
... roughly how long were you under power?
... did you check the trolling motor to be sure nothing was wrapped around the prop?
Shawn
For a trolling motor the minimum wire size is either a very short run of #8 (just a few feet) or preferably #6 or #4. #4 gauge is heavy battery cable. #6 is light battery cable. You'll lose a lot of power in the wiring if you use wire that is too small, more than 10% if its too small. West Marine has a table in the catalog or on the web site giving guidance. See http://www.westmarine.com/webapp/wcs/stores/servlet/westadvisor/10001/-1/10001/Marine-Wire.htm (http://www.westmarine.com/webapp/wcs/stores/servlet/westadvisor/10001/-1/10001/Marine-Wire.htm). For 20 feet (10 feet each way) and a load of close to 60A minimum to get 10% loss is #8. To get 3% loss you want #4 (or bigger).
If your run is long and your wire is too small it is fairly easy to fix. What you can do is buy a crimp tool that is described as a hammer type if you don't have one. You can use a 4lb hammer but its easier and a lot better to just put the tool in a bench vise. Buy a few lugs and a spool or two of wirre, one red, one black, and get a two terminal bus bar. Also buy shrink tubing with adhesive if you want to do a professional job of it and have it last. If you have an existing socket, mount the terminal bus bar near the socket, then cut the wires and crimp on some marine lugs and attach to the bus bar. Cut your heavy cables to length, crimp on the lugs and install. To be safe you should also put in a fuse near the battery (on the positive side, but you knew that I hope).
Curtis
While we're on the subject of batteries (from which I've learned some things, thanks to all), I always thought a trolling motor connection I saw on a Daysailer (I have one of these, too) was especially neat. Check out this link on Sailing Texas and scroll down through the pictures to see the connections. Pretty clever.
http://www.sailingtexas.com/soday17106.html
Jett
To extend the information Curtis was saying:
1. If you are replacing the cable, make sure it is MARINE cable. It is not cheap but it is tinned
throughout so the rot is held off much longer. The cable INSIDE the insulation rots so you
will never know until you moe the cable and it breaks inside.
2. If you do not have a set of crimps, either go to a yacht yard that can crimp the ends on
or buy a crimp tool. I was using 0 AWG cable (starter cable for a diesel and battery connection) [about 3/8" thick)]
and the yacht yard had the correct equipment to do the work correctly, the first time and it was guarenteed.
I do all my own work but there are some jobs that the professional can do in their normal operation.
3. The bigger the wire, then less the voltage drop to the motor. My starter required a #2 AWG so I went up a few sizes
so I skipped #1 and went to #0.
You battery hounds are on your own. I must bow out as this is way over my head.
All I know is my set-up works and I've no complaints. I'm not going to have a boat powered by a battery.
Do note that the solar cell can produce 16 to 17 volts BUT only 300 or so milliamps.
Not much but enough to boil the water out of the 'sealed' battery over a summer. So check the water a few times a season. Remember when you are away the battery is still cooking and loosing water.
skip.
I can't begin to thank you for all the information. Some over my head but most very practical. I have incorporated most of the advice, some before the problem (connections new, guage right, motor new, understanding #s of thrust and amps utilized, etc.). Checking some of the new insights I have come to the conclusion that I simply let the charge go down including some cold overnites. I measured the volts and the small meter used I had indicated 10+ so I falsely assumed all was well. I have been well educated (as much as I can absorb) and really appreciate the kind attention of all.
Since I'm at it, I will request any (basic, not too techy) knowledge about a solar panel trickle down that maintains charge. It appears to have a panel with positive and negatiive connection and simply keeps charge to maximum. One problem I read about is that they are not waterproof so apparently cannot be left on without attention.
"I will request any (basic, not too techy) knowledge about a solar panel trickle down that maintains charge"
The solar panel over the fwd hatch on my CP-19 came from AutoZone. It's the second one, as a guest on board stepped on it and broke the glass. It still charged OK even when filled up with rain and condensation. He replaced it. It's no bigger then the hatch and goes up and down with the hatch. It sits up on four screwed on cane tips that are 3-M 5200 glued to the hatch for cooling air under neath it. The cell is diode protected so their is no back feed from battery to cell. Wires run under the hatch and down the compression post, through the storage compartment, through the quarter birth bulkhead and under the cushion to the battery in it's strapped down box.
Don't expect too much charge. On a sunny day, the meter shows 16 to 18 volts DC at about 300 milliamp going to the battery. That's just enough to boil the water out of a good battery in a season in Wisconsin. About 7 months. Remember the cell is working even when no one is on board so check the water even if it's a maintainers free battery.
You'll not have enough generated power from a cell to carelessly use say a chart plotter and depth gauge, radio, and stereo/CD/ and lights at night on a Friday evening, all day Saturday, and a Sunday return to home port cruise. I can use just the Raymarine ST-40 when I'm sailing for three days. And short bursts of use for the other stuff.
I sail with a 1000 amp cold cranking deep cell battery. I did boil the water out of my first 1000 CCA battery a few years ago. Turned it into a jelly like inside and dead shorted out one of the 6 cells, She made 10 volts when I traded it in.
skip.
I am not sure that it would be worth putting a solar panel
when you are using an electric motor to power your boat.
If I could not recharge the battery via land power, I would consider one of the
coleman 1000W small generators, and mount a perminent charger onboard so that
when you are sailing, or just working around the boat, you could recharge.
EVERYTHING I read would tell me NOT to use the 12V off the coleman but instead use a real
battery recharger. The 12V is very dirty and unregulated which will not make your battery
happy.
My cape Dory could use a solar panel for the house battery. The engine would be started
by the engine battery and allowed to charge. I would add the house battery to
recieve a charge when necessary.
The one issue I have with this boat is that it takes a lot of power to start the diesel engine
but for the 20 minutes you need to motor to the harbor entrance, the little 35W generator has no
where near replace what it needed to start.
I bring a power battery pack (like you would use for the car), recharge that and use that to start the engine
at times...
Also, friends on a Pearson 28, tell me to purchase a solar panel regulator($30) to protect your battery because it will manage
the power, make sure it is within proper voltage range and not allow to overcharge your battery...
I have no experience with powering electric motors. I view the motor auxilliary in a sailboat more as an emergency device and am biased towards petrol-powered machines.
However, in regards to housekeeping batteries, for almost a decade I have charged the batteries in my sailboat with a flexible Uni-Solar pannel USF-11, 10.3 Watt (http://www.solarwares.com/). After all these years mine is still going strong. However, I understand that Uni-solar no longer makes them.
I always used it with 75 Amp-hour marine deep-cycle wet cell batteries and never needed a charge regulator. This is what West Marine has to say about using charge regulators with solar panels: "As a general rule panels that produce less than 1.5% of a battery's rated capacity in amp hours do not require regulation. This means that a 1.5 amp panel is the largest you should use without a regulator on a 100-amp-hour battery."
The USF-11 max output is 10.3 W and 24 V. Since W = A*V, then A = W/V = 10.3/24 = 0.43 A, which is less than 1.125 A (i.e., 1.5% of the 75 Ah capacity of the batteries I use). Hence, no need for a charge regulator.
My rough estimate was that during an average day of solar light the panel would be able to replenish some 3-4 Amps and if during a cruise I could keep my daily (and nightly) demands below that value, I would never have to charge the batteries in any other way... and so far it seems to have worked.
However, this would clearly not work for powering an electric motor that would deplete a fully charged 75 Ah battery in an hour and a half...
Hope this is useful.
J.
I would second Bob's advice to use a charger controller with a solar charger. It will protect your battery. A 12 volt wet cell battery generally should have 13.7 volts from the charger. More then that will cook the battery (for other battery chemistry's follow the manufactures recommendations). The controller will take care of that and remove charge when the battery is fully topped up. They usually have a blocking diode built in to prevent battery charge from back flowing to the panel during dark hours too.
Some of the cheaper ones I've seen will allow one charge cycle per day. That is if the battery gets topped up and the controller stops the charge cycle then no more charge until the next day. Usually that's not a problem for just keeping a float charge. Some will allow additional charge cycles if the the battery voltage drops a certain amount, indicating a drop in charge. For those who want all the whistles and bells there are all sorts of available features, meters, adjustable set points, % full indication in both charge and discharge cycles and on and on. You'll pay extra for those and they aren't really needed.
Prices start about $20 and go up to "oh wow". For a small system just get a cheap one. It's good insurance for your battery.
mel
You can get a Solar charge controller for $28 at:
http://www.emarineinc.com/products/charge_controllers/controllers.html
Look at the Sun Guard 4.5.
I use the SunSaver 10 on my setup with a Kyocera KCM40 panel.
Shawn
Bob Condon says, "Also, friends on a Pearson 28, tell me to purchase a solar panel regulator($30) to protect your battery because it will manage the power, make sure it is within proper voltage range and not allow to overcharge your battery..."
Wait a second! A $30 dollar cell...hummmmmm, I don't think it will protect the battery. I'm thinking it will not effect the battery at all. And I'm thinking it's like "peeing in the ocean to make it overflow, ain't going to happen." Good thought though. Every amp 'in' helps prolong the 'take out' factor.
I lie to myself and tell me that my solar cell is doing good, when actually it can't hurt as long as I monitor the water level of the 6 cells. Every few weeks I do hook up a 6/2 amp trickle battery charger and give her a good cooking dock side. Nice and slow.
Once the voltage drops the Raymarine ST-40 Bi Data instrument goes heywire. This unit does have a three brightness internal backlit screen that one had better remember to turn off when sailing during the day. I only use the Raymarine 435i chartplotter to adjust the dead reckoning course when sailing to Green Island and points 'Nort' when doing a three day sail. The handy feature is...'Here is the boat. And here is a line on the scope that indicates the direction were sailing' and I put that line through Green Island then note the compass lie and follow that compass line. And power down the chartplotter asap. Really works well when I can't see the island do to crud or tall waves.
Joseph says, "1.5% of a battery's rated capacity in amp hours" don't require much attention. So 10.3 watts, and 0.43 amps at 24 volts. The watts aren't as important as the amps, because amps are what you use with electric consumables on board. And amps are what boil the battery. And says, "My rough estimate was that during an average day of solar light the panel would be able to replenish some 3-4 Amps."
That is a hell of a long ways away from 300 milliamps. Even 0.43 amps is a long way from 300 milliamps. The 300 milliamps is the draw on my reciever in my R/C aeroplanes!
Additionally I might add if you sailors are using the flexible matt type solar cells that lays over the fiberglass and core construction used on some boats [not Com-Pacs] these can 'seal-in' the sun's heat and actually bubble up the cabin top on certain types of 'above water laminates'. Usually when the matt is removed or has air circulating under the cell the laminate will lat back down. It happened on my dockmate's 28 foot Sovereign. Just a though.
skip. Every lamp/bulb on the boat is an LED
(http://i259.photobucket.com/albums/hh299/1930fordroadster/ohms-law.gif)
(http://i259.photobucket.com/albums/hh299/1930fordroadster/CPElectrics.jpg)
Skip, if I may make a suggestion to buy a charge controller and mount between the solar cell and + terminal. This should avoid overcharging and instead reduce voltage to float charge the battery once it's near capacity. They also control reverse current flow during the night.
Right now you are putting too high of a voltage on the battery (solar chargers are often around 17 volts).
That will boil and destroy the battery, even at low amperage charge rates. Granted at 300milliamps, it's a slow kill and probably just reducing the maximum capacity rather than boiling the acid (tough to say for sure).
A healthy battery can take about 14.7 volts max (varies on the battery) which is typical of a strong alternators' max output (often alternators will put out less--more like 13.7--14.4 volts). As the battery becomes charged, the required voltage to keep charging is reduced (this depends on charge rate, temperature, battery type, battery age, sulfation state). Hence why they are called float chargers--they reduce the voltage based on the condition of the battery..at least the conditions that the charger is intelligent enough to know).
What do you see a max battery volts when using solar charging right now (Or rather last summer when the sun was high)?
Remember that 12.7 is fully charged...
Skip,
Sorry Skip but I find your questioning about regulators a bit comical. They work and protect batteries
and just because Comfort and Joy does not have one, does not mean they are
not a good idea.
I look at this as a business problem too. Regulator: $30 and you buy once. Good Deep Cell battery: $90 - 145.
No regulator means that you could buy a battery each year if you screw up....
Thanks
Bob
Yes as I said this is all Greek to me. I had no idea nor knew a voltage regulator could be used in conjunction with a solar cell that puts out about 17 to 19 volts.
So what do I ask for and where do I ask for one?
skip.
Skip,
See my post a little bit further up. If you want to be able to adjust the charge voltage for the battery type you need the 6 amp version or above. These are full PWM charge controllers, not just simple diverters.
Shawn
Don Casey says...
Installing a solar pannel to maintain batteries
http://www.boatus.com/boattech/casey/30.htm
J.
Skip,
You want a charge controller. For a small panel that is giving you only 300 mA, almost any charger will do and they are cheap. Boiling a batter is not cheap.
I had a small panel on a wet cell with no charge controller. Left it for about two weeks when I thought it was disconnected. Cooked a lot of water out ofthe battery. I could add the water back but it never held much of a charge after that. I had to replace it.
Put a separate fuse on either side of the battery, the charging side and the load side. Fuses should be physically very close to battery positive.
Curtis
Here is a picture. Pardon the amatuer art - I'm not a graphic designer and this was hand drawn.
(http://localweb.orleans.occnc.com/circuit.png)
Thanx Curtisv, your the tops.
Well over to Radio Shack.
skip.
Don's article leaves a lot to be desired, IMHO. Seems atypical of his work.
Curtis..very nice diagram. That's how I would install everything as well with one exception. Put an appropriate size diode in between the controller and fuse to eliminate any chance of backfeeding power into the controller or panel. With that said, most of the controllers have such a diode in their circuity so the additional diode is not needed. Specifications to check on the controller is the ability to eliminate (not reduce) backfeeding.
Using Curtis' diagram, if your outboard has an alternator on it, connect it to the CONTROLLER, not the battery, the same way as the solar panel. However if you have a modern current sensing landbased charger, you can bypass the controller. Some controllers can accept multiple connections, so buy one for your future intended configuration.
"Using Curtis' diagram, if your outboard has an alternator on it, connect it to the CONTROLLER, not the battery, the same way as the solar panel. "
Most of the cheaper solar regulators are not rated for an alternator input on them. The manufacturers specifically recommend against using them in that capacity.
Shawn
Right, which is why I said: Some controllers can accept multiple connections, so buy one for your future intended configuration.
No question as you said the type of controller you're using depends on the overall configuration. Any 'ol unit may not cut the mustard.
The diagram was for solar panel only. Most controllers don't like eithe a powerful alternator or a charger. The larger among them can take a small wind or water towed generator.
For the solar panel there is debate about whether the leakage back through the panel makes any difference or not. The diode gives you a 0.6V voltage drop which reduces that effective charging of the panel. Some chargers are smart enough to open the circuit when the battery voltage is higher than the charging voltage.
For the alternator check the charge controller spec. If the charge controller prevents back leakage then definitely leave out the diode on a solar panel. If not, then you could go either way. If you have more than one charge source, put a diode on each to prevent one from putting back voltage on the other. You can toast a solar panel with an alternator. Alternators already have diodes (a set of four called a bridge rectifier).
Curtis
btw- I'm assuming you have a small alternator on an outboard and not a deisel with 100+ Amp alternator. The controllers for those beasts are different. They cut the alternator power by reducing the alternator stator winding voltage (acutally they usually pulse the voltage, reducing the duty cycle, but I digress) as the battery state of charge goes up. These are called solid state voltage regulators rather than charge controllers.
Curtis