WAC_IDEAWORKS

There are 48v elements available out there as well.

This is wonderful! I found it on Youtube and then the Instructable link just came today. I'm very interested in making a 72v MPPT solar charger for a project electric vehicle I'm working on. My question though is regarding the mods to use LiFePO4 batteries in a 24s pack with 72v nominal... You say in step 38 (parts 1&2) to change the resistor voltage dividers and the code a bit to allow for the higher charge voltage, however since you are saying these mods can be made for 60v, 72v, or 80v, wouldn't there be different resisters for the voltage dividers for each to bring the voltage down into the acceptable range? And then would the software change each time as well, or does the change in the resisters fake it into the same range as what the 48v default would expect to see.Can you …

This is wonderful! I found it on Youtube and then the Instructable link just came today. I'm very interested in making a 72v MPPT solar charger for a project electric vehicle I'm working on. My question though is regarding the mods to use LiFePO4 batteries in a 24s pack with 72v nominal... You say in step 38 (parts 1&2) to change the resistor voltage dividers and the code a bit to allow for the higher charge voltage, however since you are saying these mods can be made for 60v, 72v, or 80v, wouldn't there be different resisters for the voltage dividers for each to bring the voltage down into the acceptable range? And then would the software change each time as well, or does the change in the resisters fake it into the same range as what the 48v default would expect to see.Can you explain step 38 specifically for the case of 72v so I can be sure I understand? Thank you! This a such a great Instructable!

Hello, Thank you for coming up with this detailed instructable! I came across the same YouTube video you referred to by Andreas Spiess, and then came here to Instructables to see if I could find someone who make this more beginner friendly for students in a school makerspace. Your project looks like it fits what I'm looking for!My question though is about the LM2950 voltage regulator, and what to do if the OLED display I want to use is in fact 5v tolerant. Although I could follow your schematic to copy what you have done, I don't quite understand what to change if I wanted to take out the voltage regulator. Will I still need all the other components? The way you have the mosfets, caps, and resisters connected, it's not clear to me what the modified schematic would look like. Would …

Hello, Thank you for coming up with this detailed instructable! I came across the same YouTube video you referred to by Andreas Spiess, and then came here to Instructables to see if I could find someone who make this more beginner friendly for students in a school makerspace. Your project looks like it fits what I'm looking for!My question though is about the LM2950 voltage regulator, and what to do if the OLED display I want to use is in fact 5v tolerant. Although I could follow your schematic to copy what you have done, I don't quite understand what to change if I wanted to take out the voltage regulator. Will I still need all the other components? The way you have the mosfets, caps, and resisters connected, it's not clear to me what the modified schematic would look like. Would you be willing to reply here or add that additional schematic to show how that would work? Thank you so much for all you have done!

I'm not sure exactly what you are envisioning... I could potentially make something for you, but can you sketch it on paper and post the image here so I better understand? Thanks!

Very true, and others have pointed out examples of wrecked cars that had adaptable racks that could be made to fit. In my case, having this new car, and not having had anything “new” in years, I either wanted a store bought new looking rack, or a rack I made new that matched my style.Half the fun was learning to make something with 80/20 parts! Now I’m making a solar panel mount for a sailboat using a combo of 80/20, extruded tube, and custom aluminum joining plates, similar in heft to the ones I made for this roof rack.

Lol, not sure if that's a compliment or just a polite opening to a series of criticisms :) Not everyone is into designing and building their own version of products that can be bought off the shelf. I recommend to anyone to go the direction that gives them the most satisfaction. I don't know about you, but I think a lot of people who are here like to make stuff :)

Thanks for posting this! I didn't know this source was out there, and it's a one-day UPS Ground distance from me :)

I'm not specifically planning to rooftop camp, but mainly because the car's roof doesn't look like it would support that much weight. I weigh about 185, so with a platform up there we're already 40-50 lbs over the roof's rating. The bolt is a sub-compact car. My wife's mini van would be a better contender for rooftop camping. We have an older Thule rack on there and on lot of occasions I've been up there on the roof securing bulky items.Regarding wind noise, with those pictured 64" cross bars, you do hear it on the highway if the radio is off. Just the rails alone don't make any noise. My plan is to not always leave these extra long bars on there though. It's actually a little dangerous, since the car is so low, and the rack so wide... The bars are at face height. I plan to h…

I'm not specifically planning to rooftop camp, but mainly because the car's roof doesn't look like it would support that much weight. I weigh about 185, so with a platform up there we're already 40-50 lbs over the roof's rating. The bolt is a sub-compact car. My wife's mini van would be a better contender for rooftop camping. We have an older Thule rack on there and on lot of occasions I've been up there on the roof securing bulky items.Regarding wind noise, with those pictured 64" cross bars, you do hear it on the highway if the radio is off. Just the rails alone don't make any noise. My plan is to not always leave these extra long bars on there though. It's actually a little dangerous, since the car is so low, and the rack so wide... The bars are at face height. I plan to have a set of short general purpose cross bars in my trunk area that I'd put on as needed for random use.

Oh, I didn't know McMaster sold 80/20! I just placed another order yesterday for a solar panel array frame... I'm hoping it's not another 2-3 weeks from the factory again!

The rails don't make any noticeable noise or affect mileage any that I can see. These particular cross bars are pretty large, and I do hear them when I don't have the radio on. I don't plan to leave the wide bars on regularly. I have a piece of aluminum extrusion that was given to me with a rounded profile on one side and square on the other. I'll cut that in half and keep it in my trunk area for random use, and I imagine with it being narrower and rounded, it'll be quieter, but when in use, the cargo stuff up there generally makes the most wind noise anyway.

Just brainstorming your caravan approach... start with some of the manufacturers who make racks specifically for your van, to see how they are attaching. Also, thanks for voting!

Great question... I should have covered that! I bought some 80/20 from Amazon and a second shipment right from 80/20. I didn't end up using every bit of what I bought, so let me total up the actual cost, and add in the aluminum plate, and report back shortly... I'll make a parts list and add it to the instructable.

OK, Check the instructable now... It's got a complete parts list. The total cost without shipping was $200. Shipping for me was about $33. Let me know if you end up making one. I'd love to see other people's adaptations!

Thank you!

Wow, where have I been... I never heard of OpenPlotter until you shared this. I am going to rethink my electronics update. Up to this point, I've been using the Navionics app on my phone on a tablet. The yearly subscription to the sonarchat data is really worth it for the increased accuracy with 1ft contour lines in places. But recently I realized for about $150 I could get the Vexilar SP200 Sonar Phone: https://www.amazon.com/dp/B00CJJBMDO This uses a dual sonar sensor to create a Wifi hot spot that send the data to your tablet or phone running navionics. So it's crowd sourcing the continual re-mapping of the bodies of water you travel, and you can download updates to the charts to get everyone else's contributions as well. It seems pretty cool in theory, although I have seen onc…

Wow, where have I been... I never heard of OpenPlotter until you shared this. I am going to rethink my electronics update. Up to this point, I've been using the Navionics app on my phone on a tablet. The yearly subscription to the sonarchat data is really worth it for the increased accuracy with 1ft contour lines in places. But recently I realized for about $150 I could get the Vexilar SP200 Sonar Phone: https://www.amazon.com/dp/B00CJJBMDO This uses a dual sonar sensor to create a Wifi hot spot that send the data to your tablet or phone running navionics. So it's crowd sourcing the continual re-mapping of the bodies of water you travel, and you can download updates to the charts to get everyone else's contributions as well. It seems pretty cool in theory, although I have seen once where it has bad data (an apparent 500ft deep spot north of the Bay Bridge on the Chesapeake Bay). But it doesn't connect to anything else. Now I'm going to look into how these two might work together potentially. Thanks for the suggestion. I might be more likely to wire the Pi in to the boat directly, since I'd have to tether cabling to my NEMA devices anyway, but I'm thinking about the pros and cons. Much appreciated!

I was thinking a simple method, a single throw double pole switch, so that as I switch the power from one to the other in one click. You could make it a 3-position switch instead if you wanted the middle to be OFF, and the two other positions to be ON with two different power sources.

Also keep in mind before removing the mast, boom, and rigging, that weight was part of the standard equipment. Putting a little outboard on like that is likely a lighter setup, not heavier. If you are going to deck it, lighter is better.I was thinking of doing this, but putting the outboard in the middle so it wouldn't cavitate or dunk in rough waters. But then you'd still need to use some parts of the rudder system or something similar to steer.Nice work though :)

Wilkinsonaw, that looks like a nice compact setup.

Thanks!