Electric Trolling Motor Battery Status Console (@tjspiel)

[Straander]

As I mentioned in another thread, I was working on a little project to supplement my 24V LiFEPO4 Battery + Trolling motor combo so I could monitor my usage in real time better. I am just in the process of finishing it up now and took it out on a trial sailing trip last Sunday.

The device is a readout display connected to a shunt I got off amazon for $20. I designed a 3d-printed PETG housing for both components that sits between my transom terminals and the trolling motor. The device will monitor the energy consumption statistics, reading out battery voltage, current, power consumption wattage and Watt-hours of energy consumed. I'm still refining the mounting provisions, but it should securely clip on to the transom between the port mainsheets block and the rudder and be out of the way for both, while being in clear view of the helmsman where he would sit while operating the motor/rudder. The screen has a toggle-able backlight for low light situations.

Keeping track of consumed watt-hours and comparing to the battery's defined capacity (about 2630) should give me a good indication of remaining range while I am out and using the motor. In addition, I'll probably print out and adhere on the chart shown below so that I can use the battery's voltage as a backup value for determining my charge state. One disadvantage to mounting this unit at the transom is that It would not account for other power draws on the battery such as boat lighting or cellphone charging that is connected in the cabin.

I used this box for the first time while motoring 2 miles to lake union last sunday. It recorded 374 watt-hours consumed for the trip which was against both wind and a mild current. This lined up pretty well with my previously assumed max range of 16 miles at full throttle in neutral conditions.

Photos:
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[Brian N.]

Very interesting project, and useful for sure.

[tjspiel]

Impressed with both the range and your device. Do you have a 3D printer or did you send the design out for printing?

I like the Wh display and think that would be the most useful for me. I'm assuming you can reset it prior to each trip? Nice to have something next to the motor.

The charge controller I have has a phone app that displays the battery voltage and I keep a chart like that handy on my phone so I can get a rough idea of charge %.

I only have two winter projects this year and one is to experiment with a Raspberry Pi with a cell modem to use that chart to send me a rough measure of charge percentage rather than having to look up it up on chart.

It would replace the iPhone I use now to send me charging status.

The other winter project is to replace the zipper on my sail cover.

It always seems like I have a lot of time to get this stuff done but I'm almost already 1/3 of the way through the off season and I haven't started on either one

[Straander]

Yes, you can reset the W-h reading at any time. And the device has some kind of persistent memory so if you don't reset it, it will continue where it left off when unpowered for some amount of time.
I am doing the printing on my own personal printer I got for $170 earlier this year. Takes a lot of tinkering to get good results, but its chugging along now. I next plan to use it to develop some kind of 3d-printed mast-gate blocker I'm going to use on my boat.

[Quantico Frank]

Wow, a 3D printer is obviously another tech thing I can't much longer without!    Have you done any other cool stuff with it, Straander?

[Riggerdood]

Very cool Straander! It's amazing the stuff that can be 3D printed. At $170, that's a tempting price to consider getting into doing that. Like Frank, I'm intrigued! I have some autoCAD experience, so that might help?

[RichardS]

Re 3D printing: Many public libraries now provide access to learning and using 3D printers. Its part of a broader "maker space" set of tools that also can include a Cricket device, and other hands on digital tools for making stuff. My wife developed this program for the high school where she worked, then taught other libraries how to do it. It does take some trial and error to get it right, although there is a vast and growing library of free templates available on the web for printing stuff. The biggest difference between high and low dollar printers is the "resolution"--fineness/smoothness of the output. High end medical uses (making bones) are amazing, low end are cool but leave some finish work to be done by sanding.Also the type of "thread" used by the printer and its strength. You can also use a 3D scanner device (plugs into your iPad) to scan an existing thing to then create the file to send to the printer. She scanned my son and made a mini version of him that is quite recognizable! Let the experiments proliferate! 

[Straander]

Wow, a 3D printer is obviously another tech thing I can't much longer without!    Have you done any other cool stuff with it, Straander?

So I've  been using 3d printers along with solidworks modeling at my current and previous job for ooooh 13 years now. Most of the coolest things I've made have been for work on much more advanced printers.

On my own printer I've made a air duct for my desktop CPU so it can run cooler/quieter. A little hook for my oven mits that clip on to my oven. Some miniatures for tabletop gaming. (those were pretty poor results even after lots of tweaking. This is not the kind of printer to get for miniatures). And then a couple of my boat projects.

[Straander]

Very cool Straander! It's amazing the stuff that can be 3D printed. At $170, that's a tempting price to consider getting into doing that. Like Frank, I'm intrigued! I have some autoCAD experience, so that might help?

A bit. I assume you're talking about 2D autocad drawing? That's kinda similar to the first step to making 3d models in soildworks and, I think, fusion 360 as the 3d shape usually start out as 2D shapes that get extruded. I believe fusion 360 is what most 3d printing hobbyists take up since its free for at-home use.

[Riggerdood]

Very cool Straander! It's amazing the stuff that can be 3D printed. At $170, that's a tempting price to consider getting into doing that. Like Frank, I'm intrigued! I have some autoCAD experience, so that might help?

A bit. I assume you're talking about 2D autocad drawing? That's kinda similar to the first step to making 3d models in soildworks and, I think, fusion 360 as the 3d shape usually start out as 2D shapes that get extruded. I believe fusion 360 is what most 3d printing hobbyists take up since its free for at-home use.

Mostly 2D, but some 3D. When I was working at the parachute company, we would use Autodesk's AutoCAD program to create 2D patterns for various equipment parts, but for canopies in particular, the neat thing was taking those 2D patterns and putting them all together into 3D models that mimicked what the canopy actually looked like inflated and in flight. This was especially useful in figuring out suspension line geometries. They usually turned out to be pretty spot-on, but you'd always need to tweak them after a few test jumps. Mostly to correct undesired opening and landing characteristics. Do you know if anyone is using Autodesk AutoCAD for 3D printing? I'm sure they must have branched out into that realm in the last 7 years since I was using that software.

[Straander]

Very cool Straander! It's amazing the stuff that can be 3D printed. At $170, that's a tempting price to consider getting into doing that. Like Frank, I'm intrigued! I have some autoCAD experience, so that might help?

A bit. I assume you're talking about 2D autocad drawing? That's kinda similar to the first step to making 3d models in soildworks and, I think, fusion 360 as the 3d shape usually start out as 2D shapes that get extruded. I believe fusion 360 is what most 3d printing hobbyists take up since its free for at-home use.

Mostly 2D, but some 3D. When I was working at the parachute company, we would use Autodesk's AutoCAD program to create 2D patterns for various equipment parts, but for canopies in particular, the neat thing was taking those 2D patterns and putting them all together into 3D models that mimicked what the canopy actually looked like inflated and in flight. This was especially useful in figuring out suspension line geometries. They usually turned out to be pretty spot-on, but you'd always need to tweak them after a few test jumps. Mostly to correct undesired opening and landing characteristics. Do you know if anyone is using Autodesk AutoCAD for 3D printing? I'm sure they must have branched out into that realm in the last 7 years since I was using that software.

All the software needs to be able to do to create 3d printed parts is to be able to export .stl files. Googling the question, it looks like autocad can do that.

[Riggerdood]

All the software needs to be able to do to create 3d printed parts is to be able to export .stl files. Googling the question, it looks like autocad can do that.

I'm not surprised at all. Even back when I was using it, we could export files to a large format (60") plotter for printing onto heavy manilla pattern stock, and later to a laser cutting table, and tolerances were well within 1/1000ths of an inch.