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    Laying out and ordering PCBs

    What are the steps in designing/purchasing a PCB to build a BMS? Do I need to generate a schematic? Which program/app? Does the schematic automatically routs traces on the board? Where does one order boards? What are typical costs of a 4" x 2" board?
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    Checking Chargery voltage measurements

    This is a heads up for Chargery as they are redesigning their BMS. Chargery has a red ribbon cable which attaches to each of the cells to measure cell voltage. There's a problem with this mechanism as power is drawn from the ground voltage sense cable and the last sense cable connection...
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    Cal's DIY BMS

    I know there are quite a few BMS out there that I can purchase. And I did try that route. Purchased a 300A and 100A Chargery BMS. Chargery did not meet my expectations. I feel that I can do better than that. So here I am. Most likely won't use my creation as I'm sure there are better units...
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    Chargery: AH measurements

    I've been working on a DIY Coulomb counter. I've noticed the Chargery SOC and AH counts were way off base. With the Coulomb counter complete, here's a comparison of my counter and Chargery's serial data. The entire test...
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    Coulomb counter for DIY BMS

    I'm currently using a 300A Chargery BMS in my motor home. Unfortunately this BMS is woefully deficient in measuring current. Resolution is somewhere around 1A. This results in the Chargery SOC gauge being totally unreliable. The gauge displays >90% SOC when in reality the battery is below...
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    Chargery V4.00 update

    Installed the new 4.0 software. Very nice that cell resistance is included. At 135A load, cell resistance is 0.4, 0.3, 0.3, 0.3 mOhm, for a total of 1.3 mOhm. Here's a plot of charging for about an hour at 5 A, then space heater load is applied at 85A, followed by space heater at 135A. AH...
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    Actually this DIY project is a high side switch, not SSR. The difference is that a SSR will have ground isolation between the "coil inputs" and the power output. In my case, I don't require isolation. This eliminates an optoisolator. Im using 6 p-channel mosfets (STP80PF55) wired in parallel...