Creating a home office in my car

Discussion in 'Gen 2 Prius Technical Discussion' started by Kent Hinson, May 28, 2019.

  1. William Redoubt

    William Redoubt Senior Member

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    There is already a built-in way to do that. It's the Internal Combustion Engine (ICE). Just add gasoline, as needed.
     
  2. Leadfoot J. McCoalroller

    Leadfoot J. McCoalroller Senior Member

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    Something like this might be in the ballpark, though I suspect you'd need two of them to keep up with the demand from the AC system.
     
  3. kevin.c

    kevin.c Member

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    Yes the AC compressor runs off the traction battery. Car needs to be in Ready mode to run the AC.
     
  4. fotomoto

    fotomoto Senior Member

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    Then use as is: zero additional costs.

    No, he wants to just run off the HV battery while on location. Like you, he wants to do it as cheap as possible; hence a used CMax, but we know it will not have enough capacity for hot Florida. Besides, condenser fans are just as loud if not louder than an idling ICE so his idea is not completely thought through.

    Yup. Plug-in's require a level II 240v charge rate to keep up with HVAC loads and not drain down the HV battery.

    This. And park in a ventilated area. Plenty of folks have successfully camped overnight in the hybrids. Supposedly some even live in them now in some areas (sad).
     
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  5. bisco

    bisco cookie crumbler

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    hey kent, i t just occurred to me, you don't mention the reason you want to do this. are you trying to keep the engine from coming on, and if so, why?
     
  6. Data Daedalus

    Data Daedalus Senior Member

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    I strongly suspect the 2nd Gen Prius has as many ECU modules on board, as the old Space Shuttle did. Almost.
    Don’t even get me started on how many sensors are squirrelled away on board, either.

    Example; the more I use the air conditioning system, the more I realise how sophisticated and simultaneously understated it really is. I wonder how many microprocessors and sensors they built into the climate control system alone?

    And then there’s opening the drivers door first thing in the morning (not always though) and you can hear the brake actuator pressurising.

    Today, in 25c of heat in London, started the HSD and taxied to the security gates - and waited for them to open. All the while running entirely on HV battery power, which also kept the engine turning (warming up) without using any petrol - I had a fully charged traction battery on my way in - the HSD was dumping the excess energy while keeping down exhaust emissions .

    Charging the existing HV battery while the vehicle is static? I believe the HSD’s conglomerate of microprocessors will disagree with his attempts and shut the whole thing down.....

    But.....by all means, he should try! He may well be a secret Nikola Tesla style genius, and succeed where others fear to tread!


    iPhone 6s +
     
  7. Skibob

    Skibob Senior Member

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    So you are already working in your car at times to avoid distractions and you would rather not put wear on the engine? It would be like pressing the start button twice to power everything up but not start the engine, just run off battery and keep the charge stable. I don’t know if a fixed power input would work. The compressor works at variable speeds depending on conditions. What you need is a prolong type setup that holds the battery at a specific charge. Like adding charge to keep the battery at 70% or something.
     
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  8. Prodigyplace

    Prodigyplace Senior Member

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    So you recommend they add another computerized system (Prolong charger) and try to convince it to perform tasks outside its programmed design??
     
  9. Skibob

    Skibob Senior Member

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    I said prolong type because it’s easy for most here to identify with. Actually all one would need to do is match the voltage of the battery at say 70% then have the amperage vary to keep the voltage stable, no? Since the car is technically on, all the existing sensors would monitor system health.

    The part I don’t know is how many amps with the car in park that would take.
     
    #29 Skibob, May 30, 2019
    Last edited: May 30, 2019
  10. Kent Hinson

    Kent Hinson New Member

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    You are not helping and wasting your own and my time. I already know how to put gas in my car obviously. Just because you are scared of the high voltage battery doesn't mean you need to be a time waster.


    The car won't shut down. It has no way of knowing where the energy is coming from. If energy in = energy out the AC unit the voltage of the battery will simply never fall and the ICE will not start.


    This is exactly right! I was actually thinking I would just use a charger set to 201v. That way it will just maintain the battery at nominal and won't ever actually attempt to charge it full. Just in case as you pointed out the AC unit pulled less power then the charger could provide. Setting the voltage to nominal instead of full will give me a good measure of safety.

    Not needed. The computer will act as normal. The battery is cooled based on tempature data the computer collects from tempature sensors inside the traction battery case. not based on amprage flowing through the BMS. Simply putting the car into ready mode before turning on the charger be sufficient.

    Yes the is correct. I will use a power supply set to 201v( the nominal pack voltage) because of nature of batteries the amperage will automatically fall off to zero when they match the input voltage. Remember amps are pulled from the load not pushed by the power supply. Over charging of batteries happens when someone sets the voltage too high.
     
  11. Skibob

    Skibob Senior Member

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    So really all you need to know is how many amps the car would draw in park with the car in ready and the A/C (or electric heater) running full blast.
    Then you can look for the size charger you would need. I would recommend a charger that could provide 100% of the needed maximum load power. That would reduce wear on the battery.
    I believe someone has mentioned what the electrical draw is on a Prius is when sitting in ready, and how much the AC draws at maximum. Add those 2 together and you have your answer.
     
    #31 Skibob, May 30, 2019
    Last edited: May 30, 2019
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  12. Prodigyplace

    Prodigyplace Senior Member

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  13. Kent Hinson

    Kent Hinson New Member

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  14. PriusV17

    PriusV17 Active Member

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    I have been charging my hv pack both from home and while outdoor using an inverter. I haven't posted anything on that because I am still 'learning' to 'see' what happens. I have only been charging to 228v max to avoid any problems.

    So far I noticed. The hv pack DOES NOT recognize the new charged voltage. When it was at 2 bars or 210v (which is where the engine starts kicking in for my v). For some reason after charging from 210v to 228v there is still 2 bars and it stays that way and then very slowly makes it way back up. So there is some kind of algorithm that prevents the system from updating instantly to the new voltage.

    I have been charging my pack when it's at 2 bars now for a while (a few months). There are things I am still learning. And ultimately SAFETY has to be top priority. So I haven't posted anything on this until I understand more. I am using a diode to prevent any power from going to the charger from the hv pack.

    I don't recommend this unless you really understand batteries and electronics.
     
  15. Kent Hinson

    Kent Hinson New Member

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    Where did you tie your charger into the system? If you reboot the car does it show the updated voltage? That's a very interesting behavior.
     
  16. PriusV17

    PriusV17 Active Member

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    This is pic of my charger. I hook the wires into the panel door opening by the side.

    hv-charger.jpg

    My best recommendation for your needs is to get a portable power station that is also solar charger ready and you should be able to work and charge from solar without any need to even tap into the hv pack.
     
  17. Kent Hinson

    Kent Hinson New Member

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    Not worried about laptop battery. I have a portable power bank for it. I also can just plug into a drop cord. I want to run the car's AC and heater without using gas.

    That looks like romex you added in orange? where did you tie the other end into the car? Inside the battery? Before or after the contractors? Does rebooting the car update the computer with the new voltage?
     
    #37 Kent Hinson, May 30, 2019
    Last edited: May 30, 2019
  18. Kent Hinson

    Kent Hinson New Member

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    Yes this is correct. I decided I will use a clamp amp meter to measure the power usage.
     
  19. PriusV17

    PriusV17 Active Member

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    The orange cable is connected directly to the hv pack with a diode. I added the cable at the same time I replaced the copper bus bars to nickle plated ones. This pic doesn't show it but it was the time I added it.

    hv-pack.jpg

    My v draws about 700-800 watts to run the AC from the hv pack. So there is no way my charger can provide that type of draw. I would not recommend using a charger with that much power for safety reason. If my car is just left on ready mode it will draw about 200-300 watts so even that is still a lot of draw for a small hv pack.

    Maybe consider a portable AC. There is only one I know that draws very low power. The Zero Breeze currently selling on Amazon for $890. I think draw is just 150watts.

    cool-breeze.jpg
     
  20. Kent Hinson

    Kent Hinson New Member

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    Interesting. The HV pack has BMS type computer on the right hand side from what I've read. It controls the balancing and also the cooling of the battery system. If you connected directly to the cells and bypassed the computer that might be why the car is not aware that the state of charge is changing and therefor doesnt bother to check the pack voltage and update the display.

    I'm curious where you got the 700-800w figure from. Did you measure with a clamp meter or something?
    If that is the case I could just parallel some power supplies. That one you are using is the 200-300v 200w meanwell right?

    Also curious what is your reason for charging your hv battery? :)
     
    #40 Kent Hinson, May 30, 2019
    Last edited: May 30, 2019
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