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Enginer kit back in the Prius with bms16c

Discussion in 'Prius PHEV Plug-In Modifications' started by Daox, Aug 20, 2010.

  1. Daox

    Daox Member

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    This past weekend I put the PHEV kit back in the car. I plugged it in to charge (it had been sitting for a while) and I left it. When I came back a while later the bms16c had disconnected the charger from the pack and I could see that a few cell voltages were quite high. How high is too high?

    Unfortunately, from sitting, I noticed the pins on the connector for the cord going from the switch up in the front of the car have gotten corroded. So, I have to get a new one of these (or a tool to put on a new connector). Any idea where I can get a 6 wire cable? I guess I'll try the local radio shack or best buy or something.
     
  2. Flaninacupboard

    Flaninacupboard Senior Member

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    Radioshack should be good, i believe it's just telephone cable that's used in the kit.
     
  3. Daox

    Daox Member

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    A normal telephone cable only uses 4 pins, this is a 6 pin wire?
     
  4. ksstathead

    ksstathead Active Member

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    So, ethernet cable?
     
  5. adric22

    adric22 Ev and Hybrid Enthusiast

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    Actually, I crimp phone and ethernet cables at work all day long. Most of the phone cables are actually using a 6-pin connector, even though only 4 pins are typically used. If you want to get really technical about it, only the center 2 pins are used in a phone connector, and many cables are actually manufactured with only 2 wires and 2 pins. So anyway, just check Home Depot and look for the RJ11 connectors and make sure it has 6 pins.
     
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  6. dan2l

    dan2l 2014 Prius v wagon

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    Hi Daox,
    No, you are best to get a replacement cable from Enginer. A RadioShack phone cable will not work.

    There are two kinds of cables. Strait through and crossover. Either will work on a phone but only the strait through work for the Enginer system.

    Go to the Enginer Forum, User section to see pictures and better explanations.

    Thanks,
    Dan
     
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  7. Daox

    Daox Member

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    I'm familiar with crossover and straight cables. Thanks for the info Dan.
     
  8. seilerts

    seilerts Battery Curmudgeon

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    The batteries begin to heat and swell over 3.7V. The more swelling, the less contact between electrolyte and conducting plates. However, the heating/swelling process is very slow. As long as the cells are packed tightly together in the case, there is little if any lasting effect from going over 3.7V. Usually my charger will push voltages as high as 3.8V-3.9V, but only for a brief time. visforvoltage and endless-sphere folks suggest that overcharging damage becomes noticeable over 4.2V.
     
  9. adric22

    adric22 Ev and Hybrid Enthusiast

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    We were discussing just putting a new end on the cable, not replacing the whole cable. So as long as he crimps the new connector on in the same orientation as the old, it should work fine.

    Although, I must admit I'm curious how it became corroded.
     
  10. Daox

    Daox Member

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    Apparently when I had the kit out of the car, there was enough moisture to cause a corrosion problem.
     
  11. Daox

    Daox Member

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    I picked up a new cable last night. I was going to get a crimping cool and connectors, but they were out of the connectors. The tool was also $30 and the cable was $3. However, it is a crossover cable. So, the plan is to cut off the end of it, and solder it in to replace the bad end on my cable.
     
  12. Daox

    Daox Member

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    I got everything back together and took it for a spin today. ~4 miles, 0 gas, me -> :D

    Now, I just need to monitor the charging cycle to make sure none of the batteries overcharge. I must say, the balancer does seem to let them get quite high (above 4V).

    Does anyone know how the low voltage limit works? I know my wife won't be attentive enough to turn it off when it needs to be. I need to be sure leaving it on won't do any harm to the pack.
     
  13. Floyd2

    Floyd2 progressio per sententia

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    Very nice Tim. According to the BMS manual the charger should automatically quit charging once a cell is either above 3.8 or below 2.5 Volts.

    Really loved the video's you and Ben put on Youtube, I ordered a 4 kWh kit and expect to receive it end September here in Europe. I will do the install myself. Why did you take it back out in the first place, trouble with the 8 cell balancers?

    I'm a little off topic here but something I was wondering: how are the two wires connected on the HV side, soldered or just screwed on? I couldn't see it in your videos, nor in the official Enginer video and the manual simply states 'connect wires'. The picture is too blurry to see how.

    About the 4 Volt charging, that seems a little high to me but I will leave it to the experts to reply to that.

    Good luck! Floyd

    P.S. I noticed that in some of Dan's cell log graphs a few cells were charged over 3.9 and one even over 4.0 V with the new BMS on the first few charges. Aparently the charger's not set that critically: http://www.enginer.us/forum/index.php?topic=214.0 Over time they seem to settle nicely around 3.8V.
     
  14. Daox

    Daox Member

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    I was going to modify the 8 cell balancers to make an automatic charger shutoff.


    There are ring terminal connectors that you screw on to the contactor in the high voltage compartment.



    My pack is a bit unbalanced currently from having to replace two cells. I am hoping that this will correct itself with the new balancer over a few cycles. I am thinking that this might have something to do with it.

    I did monitor the charging yesterday and the voltages while high, didn't seem to exceed the max I've been said shouldn't be exceeded. I think the highest cell hit 4.10V and I've been told the max is 4.20V.
     
  15. dan2l

    dan2l 2014 Prius v wagon

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    Hello Tim and Floyd,
     
  16. Daox

    Daox Member

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    Hi Dan. :)
     
  17. Floyd2

    Floyd2 progressio per sententia

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    Thanks Tim! I fully understand now.

    Hello Dan. You really know how to raise expectations, can we have a drum roll please? ...... :)
     
  18. dan2l

    dan2l 2014 Prius v wagon

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    Hi Again,
    Sorry my internet connection died in the middle of the last message.
    Here is a picture of the connection to a Gen2 Prius.
    Pigtail.jpg
    The Enginer wires are the Red and Black wires going into the Black conduit. The Prius HV wires are the ones going from the same attach points into the orange conduits.


    First, if you are seeing 4.1v, something is wrong. 4.1v is not OK. 4.2v is not the max allowed.

    It is important to understand how LiFePO4 cells get damaged.

    At the low end the cell is damaged when you try to pull electrons from a cell where the chemistry has been depleted. If you run cells when they are low they can be damaged quickly. The BMS16C is set to shutdown the converter at 2.5v, but I set my CellLogs to alarm at 2.7v.

    At the top end, the damage comes from heat. While charging up to about 3.5v most of the power goes into charging. Above 3.8v most of the power is going into generating heat. If a cell goes above 4v for only a short time there is no damage because the heat has not had time to build up. Look at the charts where the BMS16C allows the voltage to go high, you will see that this is for less than a minute. On the other hand if a cell stays above 3.8v for a longer time, that cell can be damaged because the heat inside the cell builds up over that time period.

    Thanks,
    Dan Lander
     
  19. Daox

    Daox Member

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    Well thats good to know. I do have certain cells going above 4.0V for a fair amount of time. What is the balancer supposed to shut off at?

    As a note, I have noticed the balancer reporting incorrect voltages. I had one high (3.65V) and one low cell (3.05V) at rest according to the balancer. All the cells were 3.30-3.35V when tested with the voltmeter.
     
  20. Floyd2

    Floyd2 progressio per sententia

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    Hi Dan,

    I suspected something must have gone wrong while posting your message. Thanks for the picture, very clear now. I am still ~ 16.000 miles within my warranty period and two service checkups at the dealer before I hit 160.000 km. Would it be wise to hide the Anderson connector and the RJ11 somewhere thus preventing my warranty getting void? In that case I could take out the whole box, not bolt it down, before taking it to the dealer.

    Maybe it would be a good thing buying two Cell-Logs 8S, the are $28 each at hobbyking right now. Are they easy to connect along with the existing BMS Dan?