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Zenith SupersPORT battery rebuild

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  • GiGaBiTe
    replied
    Most likely it is a thermal fuse to protect the battery.

    Leave a comment:


  • thenzero
    replied
    Originally posted by GiGaBiTe View Post


    You need nickel strips like this: https://www.amazon.com/dp/B07PQP55CM/

    Another option is to get some stranded copper wire, like 18 gauge. Strip a long section of it, twist it tightly and then hammer it into a flat strip. An issue you may have is that the copper will be a lot thicker and make the battery assembly longer, which may not fit into the case properly.

    You'll also need some fine sandpaper to lightly sand the battery tabs so that they'll take solder. You can use any kind of rosin core solder, I prefer the 60/40 leaded stuff because it's a lot easier to work with.
    Awesome, it feels like a plan coming together... One part that I'm a little fuzzy on, how do you solder the ends of each battery together, since they'll be touching? Do you sort of fold the strip over after you solder it to each end? Or do you only solder the batteries that aren't end to end?



    don't really know without seeing where all three wires go.
    It's the white one in the pics I posted. It goes to this corroded cylindrical thing that is strapped to the batteries and then to the positive end. Here's a pic if you can't make it out I'll take another one when I get home.

    95F6512D-78D2-42C7-87A3-2A6AC3901A29.jpeg

    Leave a comment:


  • GiGaBiTe
    replied

    Originally posted by thenzero View Post
    That said, I just priced the name brand D cells on amazon and it looks like $50 for that as well. And then I need some tabs and some kind of special solder maybe? Any tutorials on how to put them together that you would recommend?
    You need nickel strips like this: https://www.amazon.com/dp/B07PQP55CM/

    Another option is to get some stranded copper wire, like 18 gauge. Strip a long section of it, twist it tightly and then hammer it into a flat strip. An issue you may have is that the copper will be a lot thicker and make the battery assembly longer, which may not fit into the case properly.

    You'll also need some fine sandpaper to lightly sand the battery tabs so that they'll take solder. You can use any kind of rosin core solder, I prefer the 60/40 leaded stuff because it's a lot easier to work with.


    Originally posted by thenzero View Post
    By the way that third wire was attached to something (hard to tell because it was corroded), maybe a capacitor? and then to the positive lead of the pack. It was putting out maybe seven volts or so. Any idea what that was for?
    don't really know without seeing where all three wires go.

    Leave a comment:


  • thenzero
    replied
    By the way that third wire was attached to something (hard to tell because it was corroded), maybe a capacitor? and then to the positive lead of the pack. It was putting out maybe seven volts or so. Any idea what that was for?

    Leave a comment:


  • thenzero
    replied
    That said, I just priced the name brand D cells on amazon and it looks like $50 for that as well. And then I need some tabs and some kind of special solder maybe? Any tutorials on how to put them together that you would recommend?

    Leave a comment:


  • thenzero
    replied
    That makes sense. However, as you pointed out up thread the nimh replacements are very expensive. I'm leaning towards taking out the existing circuitry and completely replacing with some kind of cheaper/alternative setup. As an example I could hide a battery powered UPS in there, off the shelf for maybe fifty bucks. Any drawbacks to doing something like that?

    Leave a comment:


  • GiGaBiTe
    replied
    So you're getting 15.6 volts and it drops to 12 volts when you move stuff around? Your suspicion would be correct if that's the case, battery goo has seeped into the board and damaged it. It looks like it may have wicked up the inside of the wire to the connector and spilled out. You'll need to pull the board out and inspect under it. You're going to need to clean the board and fix the solder joints. You'll also need to make a new battery cable and connector to use with newer batteries, that one is toast. Fortunately that connector type is still common.

    I'd also replace that capacitor with a new one with a higher voltage rating of at least 25v, 16v is too narrow of a margin with the voltage being 15.6 volts.

    Originally posted by thenzero View Post
    Any chance the cells are still ok? How could I check?
    Those batteries are what, 30-35 years old? None of them are going to be good, even the best batteries don't last that long. You can tear the battery tube apart to look at the cells, but I suspect most of them are going to have leaked. The reason the pack won't charge is because one or more cells has either shorted out, or has such a high internal leakage that they drain the charge faster than it comes in as waste heat.

    15.6 volts is closer to the voltage of four lithium cells, but still not there. Lithium batteries wouldn't be used efficiently if you want to go with that type of battery. The least amount of fuss would be going with 10 NiMH batteries and you wouldn't have to add a battery protection board. Cell imbalance may be an issue though, you'll want to make sure all of the cells are at the same voltage before making up the pack.

    Leave a comment:


  • thenzero
    replied
    Originally posted by GiGaBiTe View Post
    Oh, the power goes directly into the battery and not the other way around, weird. Well there definitely is something going on with those regulators being in there.

    If you can find what voltage comes out of the connector with the red, black and white wires WITHOUT the batteries connected, it'd let us know what could be rigged in if you want to use lithium batteries.
    Yeah it's a really interesting/unique design! The whole battery pack clips on the back of the laptop and it has a plug sticking out that goes into the laptop where the power adapter normally plugs in.

    Leave a comment:


  • thenzero
    replied
    (ignore the minus, I was moving the probes around)

    Leave a comment:


  • thenzero
    replied
    5D65DF96-73E4-4D37-BE00-7F9B1CE54571.jpeg D876CD95-C8D6-435B-AFA8-7191E780810C.jpeg It did seem to be reacting to what I was doing. See attached. I also noticed when I pulled the connector that there is a lot of corrosion of the wires and the solder A71EBB4B-B162-49AA-9589-FF7708C11745.jpeg joints look bad. Any chance the cells are still ok? How could I check?

    Leave a comment:


  • GiGaBiTe
    replied
    Oh, the power goes directly into the battery and not the other way around, weird. Well there definitely is something going on with those regulators being in there.

    If you can find what voltage comes out of the connector with the red, black and white wires WITHOUT the batteries connected, it'd let us know what could be rigged in if you want to use lithium batteries.

    Leave a comment:


  • thenzero
    replied
    That last picture was just to show that the power supply goes straight into the battery. When it's powered, the pack passes the power through to the laptop while presumably charging the pack also.

    Leave a comment:


  • thenzero
    replied
    11EDF198-C6A1-4A2A-B5B6-3E68CFBADD96.jpeg 56F09347-8E0E-4E7B-B011-79A8C83955C3.jpeg 3E15D115-2C54-4A23-859E-C596372DAD45.jpeg

    Leave a comment:


  • thenzero
    replied
    But if I was just powering the lithium charger from the original circuitry wouldn't it just charge the lithium battery normally regardless of what that voltage regulator circuit was doing?

    Leave a comment:


  • thenzero
    replied
    Oh ok I'm with you. I'll take a better picture of it in a minute.

    Leave a comment:

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