Recent content by Wolf

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  1. Wolf

    Recommend 16S LiFePo4 BMS with atleast 100A charge/discharge and RPi monitoring?

    In my case besides having a Batrium 4 to monitor my packs I found complete monitoring of my whole system to be a challenge especially multiple parameters. So I developed my own using ESP32 microcontrollers. In my case I used 100A/75mv shunts. There are a variety of theses shunts available with...
  2. Wolf

    Your worst lithium cells

    🤣 🤣 I was going to mention the Sony US18650GR - G4 through G8 but you beat me to it. I don't think they are bad cells just that they don't play well with others. If you put them in a sandbox by themselves I think they would be OK but mix them up with other brands not so much. Wolf
  3. Wolf

    Wolf's PowIRwall

    An update to post https://secondlifestorage.com/index.php?threads/wolfs-powirwall.7804/post-78486 So I have been keeping a close eye on pack #4 voltages according to Batrium. The anomaly happened several more times and so I decided to replace the longmon. So far so good. I have also split the...
  4. Wolf

    Why won't lithium balance in series?

    The chemistry of Pb Lead acid is such that the individual cells in a ,lets say 12V battery which has 6 cells, will come to a "natural" rest voltage of 2.1V per cell for a fully charged battery. Since you can "charge" a Pb battery with a higher voltage to break down the sulfation and remix the...
  5. Wolf

    Why won't lithium balance in series?

    Lead batteries do not "self balance" they need an equalization charge every so often, especially if you have ( 4 )12v batteries in series for 48V. During normal battery operation some lead sulfate (sulfation) will build up on the plates. This build-up will continue after each recharging cycle...
  6. Wolf

    Back to planning and input welcome.

    Yep. I prefer to have a physical piece of equipment at or near each pack for temp sensing of the individual pack and if anything goes wrong with a single longmon easy to replace. With an all in one BMS package if 1 channel goes bad you got to replace the whole thing. As an end result with my...
  7. Wolf

    Back to planning and input welcome.

    I would be more inclined to go with 3s on the panels. 2s is pretty close to nominal V of the 48V battery and you want a bit of leeway to be able to charge the battery to at least ≈ 4.1V per pack or ≈ 57.4V for the Battery. A good Charge controller will handle the extra voltage of 3s just fine...
  8. Wolf

    Watts-on's DIY GTIL Controller

    GX12-2P should be the right one. Wolf
  9. Wolf

    Building my first pack, need some help.

    Are you cycling them at 1A? If not you should be. Also what is the cell part number? What is the mAh result you are getting and what is the IR of the cell. Before you commit any cell to a pack know all theses numbers. You are really playing with unknown factors otherwise. Wolf
  10. Wolf

    Building my first pack, need some help.

    Good point but no I haven't as the IR of these cells (Sanyo) is always greater than my cutoff which is ≈60mΩ, the max being the UR18650FJ at 76mΩ and only a 2100mAh cell so in my case I wouldn't use it anyway. Also with the higher IR the SOH of these cells will be lower than 80% so I would have...
  11. Wolf

    Building my first pack, need some help.

    I consider anything >0.045v too much of a voltage drop after 30 days. That being said be sure to measure the voltage of the cell right after you finish your C/D/C cycle. Not all cells will measure the same especially if you use more than 1 charger. You cannot assume that all your cells are at...
  12. Wolf

    Wolf's PowIRwall

    Interesting So I dug into the Batrium log only to find that batrium does not keep a "minute" by "minute" log or so it seems. It does however keep Min and Max cell Voltages and of course cumulative parameters such as Peak charge/discharge current. So for the type of recording that I do with node...
  13. Wolf

    Wolf's PowIRwall

    I am, although its cat5e maybe I need to go to cat6? Wolf Had to use flash but you get the idea.
  14. Wolf

    Wolf's PowIRwall

    OK this is weird. The anomaly happened again. This time on pack #38. I actually caught it in the act. This time humidity and all box parameters were nominal. Nothing drastic other than Batrium was spazzing out on cell/pack 38. Voltages where jumping from ≈3.9 to ≈3.6 in a very random manner. I...
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