connecting my solar panel to my car

Discussion in 'Off Topic' started by cregox, Dec 21, 2021.

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  1. cregox

    cregox New Member

    i've got a big solar panel grid (with 20 cells) that feeds the grid with at least 5kw on a good sunny winter day. it doesn't currently do anything else. except...

    i did connect an outlet to it, in which i can use to charge my power banks and even a macbook.

    however, this electricity must come from the grid, since it works even at night and i don't have any batteries there.

    sadly, here in portugal, i can't find an electrician to do this work for me. heck, the solar panel tracking device stopped working and all i could get in the whole year of 2021 was a single phone call with our only trusted technician to help completely shut it down and make it a fixed position grid instead! (and now i know how to do it myself).

    part of the reason i need any help i can get to learn how to do this work myself as well!

    so, to kick this off with more specific questions:

    do you think this can be done without an auxiliary battery? (and without using the power grid, of course)

    i don't care if it only charges the car when there's sun. i got 2 cars for that already... and the next generation of cars will have removable batteries (probably i will eventually get the xbus), so i will look into that later.

    and i don't need the electricity for anything else really. i live in a trailer, and the macbook isn't mine. my only electrical devices are my cellphones, the power banks, and some torches.

    i will eventually get a few more gadgets (my raspi isn't even powered on yet) but point is i don't use (at home) any amount of energy compared to a normal house (except of course for the electrical vehicle, which i currently connect to the neighbours grid). no refrigerator, no heating of anything and, as soon as i can, i will build more solar panels like nothing you probably ever seen... i won't link it here yet (again) because i'm new to this forum and i feel i am under surveillance against spam, and moderators are usually too sensitive about links... but i hope it's suffice to say that half of this amazing prototype have already been made in tamera.
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  3. bwilson4web

    bwilson4web Well-Known Member Subscriber

    Sorry but I can't begin to offer an opinion from the what you've posted. Did you build the solar system or buy it from someone else (Make and Model) including installation?

    Without a schematic, I have no ideas to offer.

    Bob Wilson
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  4. cregox

    cregox New Member

    thanks for engaging, bob!

    the solar system was already on the land when i arrived. i will try to find make and model with the owner, but he doesn't care too much for it and communication with him can be way too slow...

    do pictures help? what kind of schematic do you need?

    i hope you can follow this link:
  5. bwilson4web

    bwilson4web Well-Known Member Subscriber

    I can see pictures and they show who made it. We can then research the unit. I’m especially interested in a plate with the model and serial number(s).

    Do you have a utility meter you can see and read? We can use that to see how much is going from the utility and understanding of energy flow.

    You have just one outlet? Can you find the circuit breaker or breakers? This lets us understand how much power may be available.

    Do you already have an EV? Make and model helps understand the load.

    Bob Wilson
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  6. bwilson4web

    bwilson4web Well-Known Member Subscriber

    They "may" show who made it. If you can make photos of every legend or label, we may get what we need to contact the vendor or installer.

    My understanding is you have 220 VAC, 50 Hz. Once we know the circuit breaker rating for the outlet, the rest should be easy.

    Wiki tells me the utility reads the meter once a year and then projects a monthly bill.

    Do you have any electronics training? It may be easier to get a clamp-on, amp probe and cheap Volt Ohm Meter (VOM) to measure current flow through the wires in the exposed circuit breaker box. Is the cover still there? Circuit breakers should be protected from weather.

    Bob Wilson
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  8. The vehicle BMS (battery monitoring system) has software defined inputs for DC charging. The range of AC inputs is quite broad, while DC inputs are more tightly constrained.

    In practice, a surplus UPS from a computer server could act as a parallel reserve for power from your array. Output into your vehicle would not be high (perhaps not even as high as your domestic grid power) but it would be available to you after dark.

    There is a newly fabricated DC/DC board that uses industrial process controllers (referred to in the embedded video as "contactors") to ensure power flows into the battery and not back into the array.

    It's not an existing product, yet.
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  9. cregox

    cregox New Member

    awesome! your paragraph alone explained me better about "how they differ" than that whole article.

    i don't need night availability. i hardly need the car.

    there are at least 2 working prototypes in germany with solar panels in the car.

    but i just want to connect the solar panel to the car, no need to take the solar panel along!

    did you mean to share a different link, perhaps?

    i don't think we need so much technology for this.
  10. cregox

    cregox New Member

    thank you, bob!

    but you don't need to worry SO much...

    yes, i did train with electronics a little bit, since a little kid... back in the 80s i was helping my father to assemble micro processed boards to go into trucks and play songs for improving their street sales with music. i would solder and record eproms. but i never advanced much with my hands on electricity, nor have i ever had any teacher. and it was all in my mother tongue, portuguese.

    i do appreciate the checklists, though.

    yes, the circuit breakers are all protected.

    i've got an expensive 50eur portable volt + ohm (which i later found out have no other measurement, such as amperage) which is the first time i ever bought any such electrical tool, and i already measured what i could to understand the flow there... but i didn't open the transformer and i don't know exactly why 3 cables have 240v in them...

    you might say i have a very mixed up understanding of how electricity work, which can be very confusing. and i sure could use a teacher today!

    as for the cars:

    28kw hyundai ioniq 2016

    12kw pegeout/mitsubishi ion 2011

    anyway, back to the topic, i want to summarize all this and move forward, in the next post.
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  11. cregox

    cregox New Member

    i grab that you both believe it can be done without an auxiliary battery!

    that's perfect!!

    now i "just" need to find out how...

    i suppose that this means i'd need to do it with DC...

    and, for one, i would also need at least some sort of adapter cable, for ccs2 and chademo. obviously it would never charge at 50A, but even if it did the same speed as ac or less, i think there would still be less waste of energy this way, no?

    but i think i would prefer, right now, to focus on doing it with AC.

    so, to ask again, can i charge them with my regular outlet AC adapter from the cars?

    or should i focus on doing it with DC?!

    since the beginning of this movement, i wasn't even considering doing it with direct current.
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  13. bwilson4web

    bwilson4web Well-Known Member Subscriber

    A typical AC charging load ranges for an EV ranges from a low of about ~1 kW to a high of ~8 kW. With rare exception an EV will get 4.8 - 5.6 km (~3-3.5 mi) per kWh. But without a power schematic, we don't know if the output of the solar array goes to your outlet bypassing utility metering or if it has to flow through the utility grid and meter.

    As aa general rule, it is impractical to carry even a folding solar array to charge an EV. Look at a the size of a 1 kW array and you'll see what I mean. Worse, solar tracking for higher power and even reflective surfaces becomes difficult. Just look at the size of the 5 kW solar array with tracking.

    There are some testing of small EVs with expensive high-efficiency solar cells but they really are more proof of concept than practical. For example, the better ones will have micro inverters to handle partial shadows that can significantly degrade power output. The shaded cells will appear to be a resistor and drop the array voltage output where as a segmented solar array with micro inverters can maintain the output voltage with reduced current.

    I have thought about a towable, solar array using reflective, parabolic surfaces. But it is designed to go to a place, configure along the solar path with a battery buffer. It soon becomes somewhat expensive for the small, added range.

    Bob Wilson
  14. bwilson4web

    bwilson4web Well-Known Member Subscriber

    My understanding is EU utility grid typically delivers 3-phase power so three cables makes sense. Your two-prong outlet is just one leg of the 3-phase power.

    Doing external, DC power is technically a challenge and expensive. An AC approach is much more affordable (and safer) and if charged when you are doing other things, easily add distance. For example, one hour of charging at 7.5 kW will easily cover the distance to and return for a grocery trip.

    Bob Wilson
  15. Lee Vining

    Lee Vining New Member

    You Tuber Will Prouse said EVs need to detect a satisfactory ground to accept a charge.

    He tried charging his EV with Jackery and a few other similar brands solar portables with no success.

    We recently installed Tesla solar/Powerwall and Tesla said the same.

    Where we live code oks grounding to the neutral but Tesla said we needed to install ground rods with a leg to the house plumbing.

    Damfino but it makes sense and it works.
    BTW: Charging off my 7500 watt/220 v Inverter generator works good:


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