Sailboat Power

[ChrisOlson]

I'm actually in the process of buying a Wells Marine radar arch, which Larry Janke recommended to me since they do a lot of D400 mounts ...

We had a custom arch built by Kato Marine and we have been very happy with it too. It has survived two knockdowns in 45-60 kt winds with heavy seas, and broaching the boat once, without failure. We have about 200-250 lbs of gear on it. So I think it is pretty heavy duty.

[D_e_n_n_i_s]

Mike - Thanks for the feedback !! Got an electronic break on the wind gens to stop spin and the Industrial units that I have actually have an internal sensor that switches the stator wiring from a star to a delta configuration in response to rising internal temperatures. I doubt I'll need it, but just in case I'm not onboard when a really, really nasty storm rolls through ...

If the delta configuration still enables heat to build, there is a thermal cut-out sensor and switch causing the turbine to become an open circuit and no current flows. Once the alternator cools, the turbine will automatically re-connect.

Even though the sun is still on the solar panels, I guess they are disconnected through the MPPT controller perhaps based on voltage to prevent overcharging ??? With no moving parts I suppose the idea is that it's not going to become damaged by simply "disconnecting" it from the circuit. No free-spinning damage possible ...

Chris - Apparently these arches can carry quite a bit of weight. Gets the panels up out of the wash as well. Wow, you sure put yours to the test and it came out on top ... Nice !!! Very good to hear, thanks !! I was a bit concerned with putting weight up that high, but they really are designed for it. Thanks again !!

[inetdog]

Even though the sun is still on the solar panels, I guess they are disconnected through the MPPT controller perhaps based on voltage to prevent overcharging ??? With no moving parts I suppose the idea is that it's not going to become damaged by simply "disconnecting" it from the circuit. No free-spinning damage possible ...

Exactly right. That is one of the nice points about PV.

[Mike90250]

..Reboots itself ... Hmmm, I know that MPPT controllers measure current to select best performance of charging, but never thought about it resetting what it learned when reconnected to a different bank. It would have to go through another learning curve. Interesting ... This is a new thought for me .....

The computer in the MPPT runs off the battery voltage. When you switch it, one of 2 things happens - the controller has no place to push power to, and it's output (battery terminal) goes sky high till it hits a safety shut off, or frys. Either way, the CPU has crashed, and will have to reboot anytime the battery is switched. The proper way is to disconnect solar, then battery, switch things around, and connect battery first, after controller has done self test and is running, then switch PV back on.

You are going to need the high voltage DC breakers from Midnight Solar. And you may not find a marine version of them. If you run 2 panels in series, you could be switching 80V or more, depending on the brand/version of panel.

And you will need to label all this stuff. Maybe use a patch panel (if there is a marine version) to cover Solar A to MPPT B to Battery C (MPPT A is dead, Solar B ate a seagull @ 30 kt, Battery A is full)

[ChrisOlson]

The proper way is to disconnect solar, then battery, switch things around, and connect battery first, after controller has done self test and is running, then switch PV back on.

Gosh, that sounds complicated, though. The Battery Selector Switch in our boat never turns the power off to the panel unless it is in the OFF position. The solar controller feeds the panel bus. So we can switch it from Bank 1 to Bank 2 to BOTH on the fly and it never breaks power to the panel bus. The MidNite KID simply "sees" the different bank voltage if I switch it from like 1 to 2 or BOTH and within seconds adjusts itself.

Edit:
Oh, and one other little tidbit - if we turn the Battery Selector to the OFF position and the MidNite KID is still operating. It will simply go to Absorb V on the DC output and powers itself from the solar panels. It will actually operate the lights, fans, you name it in the boat up to the amount of power the solar panels are putting out without even being connected to the battery banks.

Second edit:
The Classic 150 does the same thing.

[D_e_n_n_i_s]

Mike - I really appreciate your level of detail and do want to understand the proper way of shutting down/starting up properly. Unless you understand how it should be done, you can't know how to take a safe shortcut, though I have every intention of doing it exactly the right way. I set up wireless on our dock and had to teach others (got tired of always being asked to do it myself) the order to reboot the devices .. Cisco AP, router (hub in our case) and DSL box. Thanks for spelling it out !!

Thanks also for the reference to the Midnight Solar high voltage DC breakers !! I'll coat the wire connections and consider using one of those silicone sprays on the inside electronics - Hopefully, everything can be opened up easy enough. It's possible to somewhat take a non-marine device and help to make it better able to withstand the harsh salt air ... Somewhat, anyway

I am very meticulous about labeling and a patch panel is a great way to go. I used a labeler to take a blob of wiring connections for the boat that I broke up into separate wires for everything & clearly labeled each on teak boards for every device. The labels have yet to peal off after years. I'd like to do the same for the solar panels as this is even more critical. In fact, I'd like to see what panels are available for these voltages going beyond a basic patch panel to provide for safety fuses or whatever folks here would recommend. A well designed patch panel would be a huge plus and I can marinize it to an extent and it's a bit less caustic down below than topside for electronics.

I believe I'm going to need something more than a basic A/B battery switch so finding where I need switches (I see that a switch may be valuable between the solar panels and the MPPT controller, but will need to be one that doesn't impact the connection for the MPPT controller to properly sense everything -and- perhaps another switch between the MPPT controller and the batteries) and a mechanism for switching so many batteries, panels, etc.

Ah, I see you've heard about those seagulls .... lol


Chris - Good to hear that there is some flexibility in shutting down/starting up/switching over the components. I don't mind going through some gymnastics as I really shouldn't have to switch things constantly and will develop a routine of it in short order, but I do need to think about some things I had not considered. I did not think about the MPPT controller as having a computerized brain in it and where it drew its power. Is it smart enough to "learn" over time and is this put into non-volatile memory so it is stored when the MPPT controller loses power, I now wonder ... I should have realized that the complicated computations for determining best voltage/amperage values was more than just a basic switch operation.

You bring up a terrific point that I forgot to even mention - Running devices directly from solar panels during the day if I get all batteries topped off. I haven't even begun to consider the safety concerns of using this in an unregulated way. It may be safer to always go through the batteries perhaps, but really, I haven't designed any power regulation yet beyond charging the batteries through MPPT controllers. Since I've really gone all power plant with these huge banks of power, I wonder if I should consider something more for safe regulation of so much power. Thoughts ??

When you run straight from the panels, does the source determine the voltage/amperage fed? This was a new concept I had to understand with the wind generators. It's the load that ultimately decides the electric current delivered to the end device, i.e. the battery is what sets the voltage (12 volts) and the amperage it can take is what gets delivered. I always thought this would have to be metered out by some smart device, but my way of thinking was wrong. Crazy stuff, this electrical power ... Thought it was just electrons being pushed with pressure downhill into a battery bucket. Rectifiers, diodes, control ... what a brave new world.

OK, enough babble from me - Thanks for the continuing education and please don't hesitate to post any level of detail. I learned quite a bit from Mike's post that I had not considered and Chris helped me to keep my perspective Please keep that feedback of all kinds coming !! Thank You !!

[ChrisOlson]

You bring up a terrific point that I forgot to even mention - Running devices directly from solar panels during the day if I get all batteries topped off. I haven't even begun to consider the safety concerns of using this in an unregulated way.

I don't think it is a recommended thing. Just the point that MidNite's equipment is able to power itself off the input source without being hooked up to the battery. I found this out when day when I shut the Battery Selector to OFF and to my amazement none of the lights, radios, etc. turned off in the boat. Everything was still running normal. I looked at the solar controller and it had simply taken the bus to Absorb V and was powering everything in the boat directly from the solar panels. I flipped off the DC breaker from the panels and then everything went dead in the boat.

I later tried this with a Classic 150 and found it does the same thing. My Schneider XW-MPPT60-150 controllers are different - they will not power themselves from the input source and if the battery is disconnected from those they shut off.

[Mike90250]

.......a terrific point that I forgot to even mention - Running devices directly from solar panels during the day if I get all batteries topped off. I haven't even begun to consider the safety concerns of using this in an unregulated way. It may be safer to always go through the batteries perhaps, but really, I haven't designed any power regulation yet beyond charging the batteries through MPPT controllers. Since I've really gone all power plant with these huge banks of power, I wonder if I should consider something more for safe regulation of so much power. Thoughts ??......

Don't do it. If everything crashes, you could patch the PV's directly to batteries, and get about half power from the panels till the batteries have enough juice to power the controllers.

If you take the batteries away, and power directly from the panels, you are counting only on the loading of your gear, to keep the PV voltage low enough to not fry the gear, the panels will try to attain their open circuit voltage, and your loads will "siphon away" some of it. But when the water maker shuts off, then your DC buss voltage is likely to spike really high, and all the smoke comes out of the electronics.

Instead, use an aux relay triggered by ABSORB to start a 10 minute count down timer, and then have that enable the heavy loads, which would be when your batteries are 90% full. If your batteries are in float, just leave the controllers hooked up, and use as much power as you can, without dropping out of float.

[D_e_n_n_i_s]

Wow, what a mistake that could have been ... So the MPPT controllers not only pick up the load from the batteries, but I'm guessing any additional load of devices hooked into the main board drawing power from it, and can regulate the charge from the panels not only to the pair of batteries hooked to it, but also to devices hooked through the main board to protect them when high-draw devices are turned off and only two LED lights are getting all the power that was being sucked down just minutes before by the watermaker !!

Got it --> Go direct only if all power on the batteries is lost and then only to charge the batteries with the board disconnected to protect devices onboard. With the size of my batteries, that would be a very rare event that they wouldn't have enough charge to power the MPPT controller, especially with me monitoring the system to keep them always at 50% state of charge or greater ... reminds me I need a monitor alarm that will go off at 55% state of charge to let me know to pull the bank off the board and just charge only. I bet they sell those too ...

Thanks again, because the manual smoke signal alarm to disembark doesn't give me much time to load up the abandon ship bag into the dinghy and start pulling on the oars ...

Study Time:
Instead, use an aux relay triggered by ABSORB to start a 10 minute count down timer, and then have that enable the heavy loads, which would be when your batteries are 90% full. If your batteries are in float, just leave the controllers hooked up, and use as much power as you can, without dropping out of float.

Some charge controllers have an AUX relay for Diversion Loads like wind generators ... Uses a solid state relay to control external DC charging sources so not controlling output ... Wait, that's not it ... Um, Need an external AUX relay triggered by the battery voltage indicating its state is Absorbing or Float and if it goes into Float (Battery fully charged), then it could start up heavy devices onboard ... wouldn't want to use the watermaker because it has some prep work before you just start making water so something else ... Oh Oh Oh, the George Foreman Grill ... crap, gotta put burgers in there first. I'm teasin' a bit, but I think I'm starting to understand ...

Close to the idea of using a relay to turn on devices, perhaps instead If I had a battery monitor that let me know a certain bank was in float (alarm monitor), then I could take advantage of the moment to cook burgers or turn up the guitar amp and play some rock 'n roll or ... I suppose do something useful like turn on the radar and see if any ships are gettin' close ... maybe turn on the SSB and get a weather fax or use some other high-consumer of power. This way, I control what devices are used when the batteries are topped off ... May just be satisfied knowing I'm fully charged for the night, but I'll probably actually start charging some laptops with their D/C chargers since those batteries never stay fully charged due to their nature.

Really tricky follow-up ... Do these MPPT controllers ever go into a sleep mode where they wouldn't immediately activate and control electrical flow to devices if the batteries were in a float state? Oooooooo Ouch !! That brick hurt !! It was just a question ...

[Mike90250]

YOU are the best battery monitor. Some have built a system integrated with weather forecast, battery state, time of day, and it decides when to start the generator.

Monitoring voltage is dicey, because when charging heavy or discharging, the voltage does not accurately reflect the state of charge. Some totalizators count amps in vs amps out, add 10 or 20% for losses (new or old batteries) and they can be pretty close. Or you watch the status of the charge controller, entering ABSORB means you've finished BULK, and if your loads knock it out of absorb, back off the loads.

If you know your controller can regulate battery bus voltage, without a battery present, and not reboot, then that sounds pretty good. You can check with the folks at Midnight ( http://midniteforum.com ) and see if this is a reliable thing to do. My morningstar mppt will not act that way at all. It's really picky about power up sequence. Just remember, change in sun angle, a quick cloud, or even a shadow, will "collapse" the array voltage, and do whatever low voltage does to your loads.

[ChrisOlson]

If you know your controller can regulate battery bus voltage, without a battery present, and not reboot, then that sounds pretty good. You can check with the folks at Midnight ( http://midniteforum.com ) and see if this is a reliable thing to do.

I don't think it is a reliable thing to do. I just happened to discover it by accident. The battery is a big capacitor that the MPPT controller needs to be able to adjust its voltage safely. Evidently the folks at MidNite decided that if the DC battery breaker trips it is best to leave the controller powered up from its input source so the AUX stays active to operate the clipper (for wind turbines). Otherwise if something as simple as the breaker to the battery trips you would have a fully unloaded wind turbine with no load on it and no way to control it. So I suspect that is why the MidNite controllers are designed that way - they are one of the few designed for wind power.

[D_e_n_n_i_s]

A solid nod to the wisdom here ... No sleeping on duty for me !! I always wondered just how accurate voltage was as a gauge for state of charge and I've read too much to make me question it as 100% accurate and Mike's post takes me quickly back to those readings. What you both say makes such good sense.

Watch the status of the charge controller ... nods in agreement again and takes away another important lesson.

Bulk, absorption and float. Reading online here:
In Bulk mode, chargers will regulate current, but not voltage. In this mode, current is regulated to the max rated output.
In Absorption mode, chargers regulate both voltage and current.
In Float mode, chargers regulate voltage.

OK, I get that Bulk mode is "let 'er rip" mode. I guess when the battery stops receiving the same current, the controller realizes that it's time to check the voltage too ?? ... and consider going to Absorption mode. Absorption mode sounds like better checks are in place by the controller. Batteries top out and charger enters Float mode so just check the voltage to see if it drops to where current needs to be checked again ?? Something trips it back to Absorption mode - Should go there before it needs to go back to Bulk mode if it's keeping an eye on the store ...

Charger goes into Bulk mode when it reaches a pre-determined voltage setting. Got to get a programmable unit with an Abacus for power conservation ... I'm thinking that testing and programming are required to really get this right. OK, I'll put on the dunce cap and sit in the corner again - Wow, no smiley with dunce cap !!

I was originally going to buy a Morningstar as they have such great ratings, but I will go to the Midnite site and continue to read and learn ...

I'll read more, but I can't help but ask if the Midnite or Morningstar MPPT controllers are adaptive ... running full power to charge from 50% to 85% and then lowering the charge form 85% to 100% (Percentages flexible)? I was hoping they were as this seems as though it would significantly improve the life of the batteries. I need to better understand this regulation also as it relates to Bulk, Absorption and Float to see how the controller makes this determination ... what it measures at all points ... how it can make mistakes or get it right.

Example: 880Ah battery bank at 50% depth of discharge will require 484Ah (about 110%) to reach a full state of charge. As the charger goes through the presets it will typically switch to Absorption in the 700Ah range. This leaves 184Ah to reach a full state of charge. If the charger is only putting out 20Ah during the Absorption mode for 1 hour (assuming an MPPT controller does this for a particular battery-No idea what it would be real world), then the batteries have only reached 80% state of charge. There it stands to reason that the Absorption time should increase by 6-7 hours before going into Float mode. Just an example, errors abound no doubt ... So it seems it would be advantageous to be able to program in Absorption mode times based on specific batteries or are the new MPPT controllers autonomous and non-programmable? OK, now I am going to get hit by a flying brick !!

Do they make an MPPT controller that can regulate battery bus voltage, with/without a battery and stay powered possibly by multiple sources? I would shell out some bucks for anything that improves regulation like that as I still feel sorely under-monitored and regulated at this point.

I really like the description of the batteries as a big capacitor for the MPPT controller ... It helps my small mind get around the big picture. I like not having the MPPT controller manage a wind generator so it's not critical that it stay powered up .. if it must go down ...

It seems like there are pitfalls with MPPT controllers also designed for wind generators. I have diversion load controls for both my wind generators and know that wind generators don't benefit the same way from MPPT controllers the way that solar panels do, so I'm thinking that I will keep those two controller separate and stick just to solar MPPT controllers. I do realize, of course, that joining both types of systems to the same batteries and same main panel will create the potential for load-sensing issues and that is what I'm desperately trying to avoid. Just tryin' to keep the batteries safe ... and the boat ... and me !!! Thanks guys for your invaluable feedback all along the way of this thread !!

Hey, this thread is for landlubbers too ... No sailboat experience required to crunch electrical mathematics or generally point out where the fire will start onboard !! I'm happy for any and all feedback. Don't mind saying, newb at the helm !!

[Mike90250]

with your loads and PV, D_e_n_n_i_s, you are seldom going to reach FLOAT on your cells. At sea, when the batteries are Life and Death for you, you should only care that you get 1 year of life from them. As you gain experience, you can load test them every 6 months, with the same test gear, and be able to figure out where in their lifetime they are.

Have you done a load budget, in Watt Hours :
TV volts x amps x hours = 500 watt hours
george foreman 1200w x .2 hr = 240wh (remember, 6 minutes = .1 hr, so that is for a 12min preheat and cook cycle)
GPS
VHF
SSB
nav lights
cabin lights
deck lights
winches
inverter (loads + 15% for losses, or whatever your inverter power curve is.)
MS power curve, page 2: http://www.morningstarcorp.com/wp-co...NG_R2_1_08.pdf
fridge
water
computers ________
total wh x .8 battery recharge losses
total harvest needed = ____________


Then guesstimate your charge WH:
800W PV x .8 x 4solar hours = 2560wh harvested, in a world of perfect PV alignment with sun & no clouds or shadows.

Do it all on paper, and then while you are on the dock and have a spot of time to adjust things (add panels or generator)

I like the idea of a towable generator that Chris uses, if you don't snag it on something and pop it loose.
Cheap, efficient mod sine inverter for simple appliances (george forman grill), pure sine inverter for the critical loads
that need sine wave. Keep the inverters off unless needed for a job, the Morningstar has a nice low power standbymode.

[D_e_n_n_i_s]

Wow - OK, now I have homework, but I guess I need more than just my initial power takeoffs ... sigh

Yeah, water generators are hard to beat. You've got to figure that water is such a thicker medium than air ... DuoGen makes a unit that can be used both for air and water, but their wind generators are more efficient and I've read mixed reviews on the units that try to do both - That's why I went with their best wind generators and will look for the yet-to-be advertised development they are working on ...

OK, I'll let the cat out of the bag first here in this forum **drum roll** ... http://www.duogen.co.uk/page73.html

Oh wait, they have a price now ... Guess it's no secret ... We don't have to pay VAT (European tax), but that price is not in U.S. dollars and that's not a good thing ... 1990 GBP ... What's that ... $3312.36 US dollars ... Gotta take out VAT, but not cheap !! 100-300+ watts DC per unit at cruising speed ... Picture one of these on each side of the Aries windvane ... Grab a pair of binoculars - I'm that bright spot you see off the coast ... yeah, that glowing sailboat that looks like the JEA plant with all their lights on

Add another pair of diversion loads to the mix ... lol Hey, I think I'll be cooking with those Origo electric elements now !! Roast weenies on the diversion load plates ... Cooking is no issue anymore

[ChrisOlson]

OK, I'll let the cat out of the bag first here in this forum **drum roll** ... http://www.duogen.co.uk/page73.html

If you don't want to beta test stuff, the Ampair (Aquair) 100 has been built in Poole Dorset since 1973 and it is proven on every trans-ocean racing yacht in existence, on some boats over 55,000 miles at sea without a failure:

http://www.ampair.com/yacht-generators/aquair-100

It mounts on a gimball on your stern rails and is designed to save the generator in the event the prop becomes tangled or hits something. You can see it on the rail and see the tow line to the prop when the boat goes down into a wave trough