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PostPosted: Fri Oct 28, 2016 5:14 pm 
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I'm a huge Torqeedo fan and if I can ever afford a pair of 403's for my TI I will buy them.
I am planning to use less expensive 12 volt panels, driving a small 120vac inverter and the AC charger that comes with the batteries to recharge the batteries. A smallish 12 vdc battery may need to be added to the system to stabilize the inverter, the 12 volt system will also power the lowrance, charge cell phones, and lighting systems. The whole works should fit into a dry box, I am planning a false bottom in the dry box with dry-rid sprinkled on the floor of the box (salt moisture is bad).
FE


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PostPosted: Fri Oct 28, 2016 6:54 pm 
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I now own two working 403 motor pylons (due to a faulty motor while on an off-shore daytrip to Anacapa island) and am considering a dual motor setup, but I am not sure if my PVC mount setup will support them. I am currently debating whether to purchase a second throttle ($300) to power the system. If I do end up implementing this dual setup, I will post some photos and statistics. I am curious from an engineering perspective how fast (and how energy efficient) this system will be compared to just using a single 403 (1 HP propulsion, 2 HP thrust) Ultralight motor. I am interested in the opinion of others on this if anyone has any idea about these questions.


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PostPosted: Fri Oct 28, 2016 7:11 pm 
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You will need custom higher pitch props if you ever want to get up to 10-12mph cruise speed with twins (my cruise speed requirements).
FE


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PostPosted: Fri Oct 28, 2016 10:44 pm 
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I'm not really sure why you would want to use an inverter and another battery. It looks to me that they are 24v panels which you can buy (inexpensively) or series 2 x 12v panels. That way you have straight DC to DC not DC to AC then back to DC which means you will loose in efficiency. Also having 120v AC on board may be a bit of a safety issue. Just my thoughts I hope to fit one soon and when I do I will work out the solar issue and post some pics and some ideas if that helps.

Cheers Mate


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PostPosted: Sat Oct 29, 2016 7:09 am 
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those motors are likely already propped correctly for how fast you will go with them. Assuming Torqueedo did not do a good job wiith the prop.. hmm.. probably a good way to waste your cash, possibly even damage the motor.. You can incorrectly assume that if you increase the pitch, the prop will "bite" more water and produce more thrust. What actually happens is that the rpm of the motor will decrease. Remember that power delivered is RPM times torque. Torque goes up, RPM goes down. You cant take a motor that will only safely produce 1/2 hp without over heating and make it produce 3 hp by just changing the prop.

If you do get the two motors or just one and you have the readout that shows instantaneous watts being used along with speed, note the watts used vs speed for a variety of speeds. This would just take a second to get the data.

If you dont go with the Torqueedo solar (45 watts is not much power at all - it would probably take just under two days to recharge that 320 watt*hour battery), I think a charge controller something like these https://genasun.com/products-store/mppt ... batteries/ would be best. The charger has a voltage algorithm that you need to match to the battery voltage and technology and that will be the hard part. I think the Torqueedo battery for that motor is 29 volts or something like that.. A MPPT controller like the Genasun will be very efficient for converting all the power from the panel to battery charge. I thought they had a slightly more expensive option for a custom voltage but didnt see it on that web site - also didnt spend much time looking.

FE, Im mot sure the solar panel directly into an inverter will even work. The solar panel is basically a constant current output and the inverter is expecting a constant voltage input. I would guess it might work if conditions were just perfect but would likely not work for a bunch of conditions. To add the intermediate battery gets complicated as you may also need an additional charge controller between the solar panel and the intermediate battery. This will also be very inefficient compared to finding a charge controller that goes directly between the panel and the battery. The inverter might pass only 80% of the power (specs are usually off, this is what I have seen measured) and then the AC battery chargers are also maybe 80 to 85% efficient partly because of power factor..

One more note about the solar controllers. The MPPT type of controller can (if they are designed for this) allow you to use different panel voltages compared to the battery voltage. If you can match the controller output to the battery, some of these will work with 12V, 24V or even 48V solar panels. The flexible panels are usually 12 volt but for the lowest cost per watt, the panels are usually higher voltage as that is where the volumes are.

Edit.. also I would not use a large solar panel directly charging that battery unless you are right there watching things and know what you are doing. Especially with a Lithium battery!! I think this could be a very unsafe thing to do. The right solar panel to battery charge controller would make it safe plus will achieve the highest percent of the panel produced power going into the battery.


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PostPosted: Sat Oct 29, 2016 8:19 am 
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Charging the older style Torqeedo batteries from alternate sources such as solar panels used to be challenging. However the newer 2015+ batteries now incorporate more friendly alternate source charging circuity inside the battery itself.

Here is the new charging spec from the Torqeedo manual:
Image

So it appears the newer batteries will accept any DC Power source from 9.5 to 50 Volts DC as long as it can supply at least 4 Amps of current.

I've tested this a bit and found the batteries prefer voltages around 20 VDC or more with at least 3.75 Amps. If I use 12VDC at 4 amps, the batteries will still charge but sometimes not to 100%. That's not a huge issue but it's nice to get a full charge as opposed to 95%. I've discussed this with Torqeedo and they said at lower voltages/currents the battery might not charge fast enough before the circuitry enters a sleep mode. This doesn't make a lot of sense to me but they said it had something to do with the USB adapter they now include. They didn't want the battery to fully discharge if someone left something that was drawing current on the USB adapter. So they incorporated a sleep mode. I have no idea why this should include the charging circuit.

Since the internal battery circuity appears to be limiting the charging current to around 4 amps, the only way to charge it faster is to supply more voltage (Power = Volts X Current). If you don't charge the battery fast enough before it enters the sleep mode, you may not be able to charge it to its full capacity, depending on its initial state of charge when you began charging it.

Torqeedo may fix this issue with a software or hardware tweak, but for now just be aware of it when selecting a charger. The good news is that a very wide range of DC power sources can now be used.


Last edited by pro10is on Wed Jul 12, 2017 11:25 pm, edited 1 time in total.

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PostPosted: Sat Oct 29, 2016 8:47 am 
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With that internal circuitry, you "may" be safe to just hook up a solar panel. And it also sounds like you probably dont have access to the battery voltage directly - which probably is a good thing safety wise.. But that likely elimiates the possibility of finding a really nice solar charge controller that is matched to the battery.

One question regarding the use of the solar panel.. A solar panel will have a maximum power point voltage https://www.solar-electric.com/mppt-sol ... lers.html/ and when operated at this voltage, will produce the most power possible. The MPPT type controllers will do a quick voltage search by varying the load and measure the power at each voltage and then operate at that voltage where it saw maximum power output. They use magnetic switching circuits to then convert that power from the panel to the battery.

That circuit that comes built into the battery could very easily actually come with that maximum power point feature. If so, it would also be efficient to connect a solar panel directly. If it doesnt, it still might work fine but you might lose some efficiency.

Any way to know? If you buy the Torqueedo solar panel, does it just connect directly to the battery - no external box/ circuit required?

This also only covers the case of charging the battery seperately with solar (battery is not connected to the motor). It does not cover the case where you might want solar charging the battery while it is being used. Maybe not an issue depending on why you wanted the solar in the first place.


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PostPosted: Sat Oct 29, 2016 4:52 pm 
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That is some good information Walt and pro10is. You seem to be making the same assumptions that I am. That is it appears the battery system includes a tracker to provide DC to DC conversion and some regulation system. Normally with Lithium batteries each cell must have a separate Battery Management System (BMS) which provides regulation.

So I will go ahead and order I don't see it being an issue of providing load whilst charging as this is a generally accepted function e.g Tesla walls etc.
Given a minimum current of 4 amps I am wondering how a 45W panel can provide this though. I am think 2 12v 75W flexible panels strapped to a trampoline should give me about 34v with about 4 Amps. I don't think physically it will be viable to go any bigger. Anyway that is my plan so I will go ahead with that and report.

Cheers


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PostPosted: Sun Oct 30, 2016 5:47 am 
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The system I was describing (with 12v panels) was described to me by a guy who was entered in the Everglades challenge a couple years ago in class 6 (experimental electric). He had a Windrider 17 with a torqeedo 1003. He had If I remember correctly 2 large 12 volt solar arrays, connected to a 12 volt battery. This was a couple yrs ago and I don't think the torqeedo battery systems had the enhanced charging capabilities of the current systems.
It's always been my impression that charging lithium batteries is a much more complicated (and possibly dangerous) affair. I for one would feel pretty sheepish if I trashed or cut the usable life by 3/4 a $900 dollar battery because I didn't charge it correctly.
I suspect that guy setup the way he did because he didn't have an unlimited budget and was trying to adapt a more cost effective more commonly available system to the task with minimal risk. My reasoning for using a small inverter and the factory supplied torqeedo ac charging system may not be the most efficient method, but shouldn't void the warranty on these extremely expensive batteries (a conservative solution for a non expert in lithium tech).
As everyone knows I've been working 5 long yrs now trying to come up with a human/battery/solar/wing tri-power sail boat design that can complete the 300 mile race non stop averaging 10-12mph in 25hrs or less, (I stated that objective 5 yrs ago)
My current design with hybrid gas engines can easily accomplish the task, but as everyone knows supplimental hybrid/gas propulsion is not allowed in the competition.
The key point here is the average speed, there is no way I'm going to sit in that boat for 4 days just to prove some silly point going 3mph. I can't pedal 4 days straight, but can pedal for 24 hrs with a few breaks, (keep in mind my flex 90 eclipse mirage pedals take much more peddling effort vs standard mirage drives, but are neccessary because of the proposed speeds (standard mirage drives can't provide useful propulsion at speeds over 8mph, the boat is traveling at 10-12mph so standard mirage drives would be kinda useless). Obviously with two athletic peddlers we don't need any supplimental propulsion at all, but we are completely exhausted after an hr or so (lol in my case 2-4 miles).
Realistically the necessary battery/electric Technology is still 10 yrs out but it's been a lot of fun trying to solve, (the extreme down side to being an inventor).
Being a huge Torqeedo fan, it's pretty likely my final solution will likely involve stuff from Torqeedo unless I design and build my own motors.
Here is the video of that guys Windrider 17 ( I don't know him or his name, or where he is from) from the 2015 EC. His boat is shown around minute 3 into the video (spoiler alert: you may want to fast forward, the video is extremely boring). His boat has about the same sail area as mine with a similar setup (all sails on furlers), the only difference being I'm using a wing sail vs his standard jib, plus my rig weighs around 200 lbs less, both boats are 12 ft wide for added stability. I have no clue how he did in the race. It appears there is very little interest in this kind of stuff, just us crazy mad scientist types ( lol).
https://www.youtube.com/watch?v=e05gGHpUYjg

FE


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PostPosted: Sun Oct 30, 2016 10:21 am 
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FYI, I doubt a 12 volt system was used since all the torqueedo smaller motor run off 29 volts. The 2000 watt Torqueedo outboard requires 24 volts. The reason for the higher voltages is that parasitic power loss in the wires used in the motor and for also getting power to the motor decrease with the square of voltage. Ie, double the voltage and the power loss in the wire due to resistance drops by a factor of four. Higher voltage allows smaller (and lighter) wire to be used.

Quote:
Since the internal battery circuity appears to be limiting the charging current to around 4 amps, t


The two 75 watt solar panels could be interesting but from what Pro10is had said earlier, it looks like that internal battery circuit likes to see a source with over 4 amps but the quote above also says that even if the source is capable of more than 4 amps, the charging circuit will still only accept 4 amps.

The immediate and probably big problem you might have with the two 75 watt panels in series is that at full sunlight, they would be producing just over 4 amps and the charger could possibly work. However, if the day were just a little hazy, the panel current might cut back to say 3.5 amps and now you get ZERO charge even though nearly 120 watts was still available from the panel set. Partial shading of those panels on the tramps would also be very likely and that likely may also drop the output out of the range that the battery charger circuit would accept.

If I were doing the solar power route, I like the idea of putting some "real" panel power on the tramps. Pro10is says that he gets reasonable speeds with power under 300 watts (hopefully sometime.. someone measures the speed vs instantaneous power on a TI so we wouldn't have to guess). But.. it could be that a couple hundred watts of solor gets you speeds of 4 to 5 mph just off the sun which isnt all that bad. If you are stuck using that battery charging system, it wont accept more than 4 amps.. so you may be stuck with lower power solar panels. I think you would also be stuck using one battery for the outboard while you were charging a separate battery. Not a huge hassle however..

Torqueedo has a 2000 watt outboard that is designed for an external 24 volt battery. This seems to be the lowest power one I can find that runs off an external battery. Personally.. my gas outboard solves every problem I have but if I wanted a more powerful solar option, I would build it around that 2000 watt motor (an actual 2.58 hp) - you dont need to run it at full throttle but could. Then build your own 24 volt battery with at least 1000 watt hours of capacity, maybe even 2000 watt hours. Link the solar panels to the battery with a MPPT charge controller like the Genasun I linked to earlier like this one (assuming your battery technology is Lithium) https://genasun.com/all-products/solar- ... ontroller/

The battery is still connected to the outboard at the same time its connected to the solar panel through the charge controller. If you are motoring slower and using less power than the solar panel is putting out, the excess goes to charging the battery. Crank up the power and the solar cant keep up so you are using some of the battery capacity. Turn the motor off, all the solar goes to charging the battery. All automatic and the MPPT solar charge controller is always getting the very maximum out of the solar panels possible regardless of the conditions.

Because of the mast or mast and sail, you are likely to have a shadow on at least one of the solar panels. Partial shading really degrades the panel output so an improvement to the above is to have a separate MPPT controller for each panel, the output of each MPPT controller connected to the single battery.


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PostPosted: Sun Oct 30, 2016 2:10 pm 
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walt wrote:
The immediate and probably big problem you might have with the two 75 watt panels in series is that at full sunlight, they would be producing just over 4 amps and the charger could possibly work. However, if the day were just a little hazy, the panel current might cut back to say 3.5 amps and now you get ZERO charge even though nearly 120 watts was still available from the panel set. Partial shading of those panels on the tramps would also be very likely and that likely may also drop the output out of the range that the battery charger circuit would accept.

Torqeedo specs 4 amps because that is the optimal current for their internal charging circuitry. Anything over 4 amps will be current limited. However lower currents will still charge the battery. The only issue is that lower currents may not charge the battery in time before the sleep mode activates and thus you might not get a full charge. Unless I'm mistaken there is probably a way to wake the battery circuit up to continue charging. Probably just by attaching it to the controller and turning it on, but I've never tested this.


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PostPosted: Sun Oct 30, 2016 10:51 pm 
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thanks for all that nice bit of spitballing. I now have a plan. I currently have a 12v 36Amp LiPo4 battery to use for the sounder/GPS. I will run an output from this to the 403 battery charging input. I will continue to charge the 12v battery with the one 75W flexible panel I have and if I really need it parallel another 75W at a later date. I can incorporate a switch between the two batteries and stop the charge if I want to. All in all it will increase the available power available without a major cost.

Cheers


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PostPosted: Mon Oct 31, 2016 5:48 am 
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My situation and needs are very different from everyone else's. Because of my higher minimum cruise speeds (10-12mph), and max speed (15mph) all my equations and power requirements are very different. In my situation the propeller itself is critical to all my equations. An analogy of a propeller in operation is a nut spinning on a threaded rod. At a fixed thread pitch at a certain rpm the nut will travel down that rod a certain distance and speed (not accounting for slip and prop loss). There are tons of prop pitch vs boat speed calculators available on line. It makes no difference what your horsepower is, or how many motors you have in the water, or the size and weight of your boat, that pitch number is constant.

All my calculations are completely upside down from normal calculations because of my tri-power system. A normal hp/prop calculation would be multiply the max rpm x pitch x some boat length drag and loss numbers = horsepower requirement to propel the boat at X proposed speed. With my boat that number is likely around 15-20hp for my max designed speed (15mph in this example). You can actually test this number by dropping a free wheeling prop in the water and measure the rpm at a given speed (in my case 15mph). I have to adjust the prop pitch to insure I don't exceed the max rpm of the motor (if the max rpm is exceeded the motor explodes (I have exploded a couple already accidentally). Now I calculate backwards my horsepower requirements. With my current setup my hybrid gas motors are outputting exactly 1 hp each, if my hp requirement to propel the boat at 15 mph on plane (I have a planing type hull), if the hp requirement is 15hp, and the motors are providing 2hp, then the sail and pedal system has to provide the remaining 13 hp.
In my case the battery/solar power consumption number will be a fixed number, just a wild guess at this time is 500 watts per motor (I'm just guessing here if at max power the motors are consuming is 1000 watts ea, I will want half that number). Now I only need to provide enough storage energy to provide 500 watts per motor (1000 watts total) power times 25 hrs of continuous operation. Some of that energy will be supplemented by solar cells (during daylight), and some will be provided by my fuel cell (aux storage energy), the rest needs to be from stored battery energy, how many batteries that comes out to is totally unknown at this time.
Here is one of my spreadsheets attempting to calculate my power requirements, this one only covers points of sail from zero to 20 degrees off the wind (direct upwind), there are six more spreadsheets needed to cover all the other points of sail, and wind conditions. What I do is is go out and test in different conditions, then record my speeds and fuel usage. Once I know my fuel usage in given conditions I can hopefully convert that to electrical energy storage requirements.
Image
These calculations were done a couple years ago, and only account for my current system which has a cruise speed of 8-10 mph. As I have stated my desired final cruise speed is 10-12mph, which the current configuration is not capable of providing, I have to convert to a full wing mainsail to achieve the 10-12 mph cruise figures, which is designed but not built yet. Once I get all the rest of the calculations and testing out of the way I will likely build the new mainsail (I'm years away realistically).
Going in nobody know what the actual sailing conditions will be thru the race, this is why I need to have available up to 260 sq ft of sail area to be able to adjust sails to suit whatever conditions I come across. Working with a fixed energy consumption limit makes the task daunting.
With my hybrid gas system, it's easy to just increase throttle slightly to make up for the sails and pedals not providing quite enough energy (or pedal harder). Because the energy density of gas is 100x higher then electric, it's easy to just carry along an extra gallon or two of fuel to make up the difference and variables. You can't do that with batteries and solar cells (if your batteries go dead halfway thru the race, with no means to recharge them, you are done).
As battery and solar tech improves, I get closer and closer to actually being able to pull this off. The information you guys are providing as this stuff advances is extremely valuable to me. The newer batteries from Torqeedo, and the ability of their system to be able adapt to and utilize input power from solar, and fuel cell aux power sources is monumental toward my goal.
From the information you guys are providing me, I may just be able to pull this off with 4 rotating banks of battery sets (4 battery sets for the left motor, and 4 battery sets for the right motor). With the fuel cell charging one bank (though I may now need two fuel cells), the solar charging another in a round robin fashion. This is 5 yrs ahead of schedule.

My ideal situation would be in normal sunlight (after all it's Florida) to not use any battery power at all during daylight, but still be able to charge the batteries on top of driving the propulsion during daylight hrs would be a really big plus.

I'm sure all this sounds insane to everyone (sorry for the long explanations).
FE


Last edited by fusioneng on Mon Oct 31, 2016 7:46 am, edited 3 times in total.

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PostPosted: Mon Oct 31, 2016 6:58 am 
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Grover, I would still think about adding a solar charge controller between the 75 watt panel and the 12 volt battery. That is a lot of power and not a very big battery and its damage you should worry about. Lets say your 12 volt battery starts off fully charged and you connect the panel up to it plus the Torqueedo battery. The Torqueedo battery will only accept 4 amps so about 50 watts or so (12.5 * 4). Your 75 watt panel could be completely supplying that during the charging and you never use any charge from the battery. After some time, the Torqueedo battery goes into sleep mode and is no longer taking any charge, that over 4 amps of charge from the solar is still going into the fully charged 12 volt battery. That could take the voltage way up over 15 volts pretty fast and boil or damage the 12 volt battery.

If you had a solar charge controller, one of the things it will do is limit the charge to the battery once its full. If its the MPPT type, it will also operate the panel at its maximum power point and you will get an extra 15% out of the solar panel (average number.. depending on conditions the boost varies somewhat).

Cheapest (not MPPT) might be something like thiis https://www.solar-electric.com/sg-4.html or this https://www.solar-electric.com/ss-6.html

I like those little Genasun MPPT controller (I have one in my sailboat which only has a 20 watt panel) This is the one I have https://genasun.com/all-products/solar- ... ontroller/ but you could go to higher current if somehow you can come up with a way to use higher power in the future.

Edit - woops, I didnt see that your 12 volt battery is LiPo4. All the charge controllers I linked to are for lead acid. The regulation numbers are likely slightly different for the LiPo4!!! I didnt go back and correct those links but your solar charge controller has to be set up for LiP04!!!!


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PostPosted: Mon Oct 31, 2016 1:51 pm 
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Walt

Thanks mate I do have a BMS/Solar Charger for the battery already sorry I didn't mention that this system is already setup. Even a lead acid would do if anyone was considering it I just happen to have the LIPo4 battery which I set up for weight reasons. If I was using a sealed lead acid I would use the Low voltage cut off from the regulator to ensure I didn't run the lead acid down to low.

My typical use would be say running the motor for about 2 to 3 hours to get to some good fishing grounds then whilst I was there letting the batteries transfer then head home on a relatively charged battery with enough reserve just in case. I am sort of looking to save some costs I do very much like the torqeedo system it is just the cost of their batteries that I cant accept. BTW I am a stand alone power designer and installer, but always open to learn more.

Cheers guys


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