Good recommendation! Even if he’s not interested he’s in touch with other battery recovery companies he could (hopefully) recommend. Here’s his web site @BenjaminF:
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And also a believer in Jason Potter. 🤦🏻
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I know nothing about Jehu, but I firmly believe Jason just took advantage of him based on the kind of person he is. I’m sure Jason explained everything away and Jehu wouldn’t have known where to look to find the truth.
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I also would like to believe this is what happened.
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Alright I tried my best but I’m reaching out once again for advice.
Background:
10s5p would drop ~2v right off the charger. Got a smart bms installed and saw one p group sitting low.
Fully charged:
After some discharge:
Started tearing out the p group.
Started isolating cells and they’re all at a relatively similar voltage level… No dead outliers. Measuring the internal resistance gives:
Compared to a fresh cell IR of ~53 mOhm
I don’t know if that p group being wonky for a while would cause that, if replacing the whole p group would fix everything, or if I should just cut the pack down to 4p.
What would you do?
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How did you measure the internal resistance? Are you confident your measurements are accurate?
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Before replacing always try to work/ improve on what you have. Try bringing the p group up to matching voltage with a slow charge and give it a run. If they are damaged internally ¿ they will show you within the first ride. How new is this pack?
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D6 pro
@Bigdaddyhawk, the pack is 2 years old but acted funny from early on. Bms would get stupidly hot when balancing and I had a feeling something was wrong.
Bringing that p group up slowly worked but it still dropped off pretty quickly the second we removed the charge leads.
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140-170mOhms is astoundingly high and a really bad sign. New Samsung 30Q’s have a DC IR of about 22mOhms. All the cells in that group being that way is very strange too.
I can see one cell doing that but all of them? Could that p-group been discharged down below zero volts or badly overcharged?
Carefully charge each cell in that group separately, let them rest for a couple of hours, and then measure their voltages. Leave them for 24 hours and check voltages again. If there’s much more than a few millivolts voltage drop (should be less than that though) then that cell is probably badly damaged. The high IR already indicates that but a high self-discharge rate is another good indicator.
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Bruh, if that’s the Hyperion battery, might as well says its fucked. Seeing all the batteries that they built and hearing the same issue over and over about them, I can possibly assume they used shit cells when building them.
Around half of the cells in the 12s5p 30q they built for the mbs were well over 100 mOhms. Ended up trashing (disposed of properly) the battery and building my own.
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Yeah that’s kinda what I’m thinking. Probably going to just scrap that p group and hope the rest hold up a bit longer. I haven’t made any esk8 purchases this year other than consumables like tires and pulleys so I’m overdue for a larger esk8 purchase.
Gonna check out the rest of the p groups and see if they hold charge as they should and we’ll see.
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…something just occurred to me…I’m wondering if those cells might be fakes. The chances of that are tiny but it’s easy to do some checks.
Carefully remove the wrap from one of those 30Q’s. Was the white top insulating ring free-floating or self-adhesive (stuck to the cell)? Stuck = fake 30Q.
Are there printed codes on the metal can? What”s the top line of code, near the top of the cell?
On the bottom of the cell, are there one or more characters stamped into the metal can, near the outer edge?
Underneath the top contact, are there a couple of characters stamped into the venting disk?
All these things are what genuine Samsung cells should have. The top code line helps to identify which Samsung it could be…if there.
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So I’m building this battery… do you guys think I’m doing alright? I got the nickel with the slots for extra hoorah!
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Corners aren’t sharp enough. Needs more fire also.
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I thought you were going to bed… also I hear you have hot memes for that. 
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Two spot welds might not be enough. That’s good for like 10 amps right?
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I call it the cloak and dagger feature…
That’s assuming they both hold.
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What is this?
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