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  1. martyfarkle

    BMS MOSFETs Explained

    What is the best way to limit the charge controller to keep the SOC between 20% and 80%, never going above that or below that? As I understand, the LifePo4 cells like that range but don't like both extremes. The reason I ask, is that I use very little electricity during the day and would like my...
  2. martyfarkle

    FOR SALE: JBD 8s 100 amp BMS w/ Bluetooth + Ring Terminals

    I did end up buying one elsewhere. Thanks for your response. Cheers Mark
  3. martyfarkle

    Small wind turbines no longer worth it?

    I have looked a great deal into Missouri Wind and Solar and they seem to be one of the best I have found but more expensive. Much better than any Chinese rice paper fans. They are US made, as far as I can tell, and sound pretty darn rugged and deliver a heap of power. You have a different...
  4. martyfarkle

    Are Trina 400w panels any good?

    I am trying out 2 new Trina 400w panels. The main disadvantage is that these panels are huge: over 6 feet tall and over 3 feet wide and almost 60 pounds each. I have them both propped upright on the balcony of my flat. I have them in series connected to a 60a Epever controller. They are facing...
  5. martyfarkle

    mt50 programming questions

    Over voltage disconnect at 32v! That's like 4v per cell and isn't 3.65v the highest they should be allowed to go, then to keep the SOC cycles between 20% and 80%, it should be lower still. This is for solar and not EV. Would 28v be tops for charge limit, that's 3.5v per cell? Battle Born sets...
  6. martyfarkle

    Small wind turbines no longer worth it?

    If (and when) I have a play with Wind turbines I am impressed with Missouri Wind and Solar (https://mwands.com/). They seem to have pretty reliable and solid products. They are not cheap, but not super expensive either. They have a lot of very useful videos as well. Solar is definitely a nicer...
  7. martyfarkle

    Why don't we get more from 800 watts of solar panels?

    I have two MPPT's, Epever 30a and Epever 60a. Configuration now is 4x100 watt panels set up as 2s2p (is that right symbol?), using 30a CC with a 12v Battery pack consisting of 8 120ah cells. Has been working great but.... I will eventually use 16 120ah cells configured to be a 24v battery...
  8. martyfarkle

    Why don't we get more from 800 watts of solar panels?

    Is there a calculator that would figure out total power at the charge controller by entering in panel configuration with mixed parallel and series? For example: I have 8x100 watt panels and I am going to configure them in 4 sets paired in series and then the whole lot in parallel. Is that 4s2p...
  9. martyfarkle

    Overcharged lifepo4 cells: Help!

    This is bizarre... my 'overcharged' 120ah cell capacity came in at 124ah. I started from 3.65v and went down to 2.6v. Now I was sure that the capacity would have been diminished by 10% or so. If amps are amps are amps then my cell actually had the 'fear of DOD' put into it and performed better...
  10. martyfarkle

    problem with capacity tester?

    This is bizarre... my 'overcharged' 120ah cell capacity came in at 124ah. I started from 3.65v and went down to 2.6v. Now I was sure that the capacity would have been diminished by 10% or so. If amps are amps are amps then my cell actually had the 'fear of DOD' put into it and performed better...
  11. martyfarkle

    problem with capacity tester?

    When you say 'supply', is this referring to the ‘Power Supply’ or the ‘capacity tester’ you are talking about? I need to calibrate my Capacity Tester. Now it is saying voltage is 3.17v and my meter says the cell is at 3.605. I am testing another cell. So will the tester be basing the running...
  12. martyfarkle

    problem with capacity tester?

    I have the same unit. I have been trying to calibrate it and now it is stuck on the wrong cell voltage (.15v lower than voltmeter) and won't go above 5.64 amps, no matter how much I turn the two knobs. Also when the knobs are all the way counter-clockwise as soon as I connect it to the cell it...
  13. martyfarkle

    Overcharged lifepo4 cells: Help!

    Here is a photo of the correctly top balanced cells next to the overcharged ones. What I was planning on doing is making up a 24 V pack with 16 cells. But if I parallel each good sell with a bad cell and then put those in series for 24 V will that be OK? Or will it be a very bad move? I realize...
  14. martyfarkle

    Overcharged lifepo4 cells: Help!

    Thanks, guys! Yes, I think it would be best for me to top balance them again (watchfully) and then I am sure I have it right. They 'appear' to be all within 0.003v of each other on the BMS monitor but the capacity might still be way off, since they are below the 'knee'. Need to get it really...
  15. martyfarkle

    Overcharged lifepo4 cells: Help!

    In my case, after sweating grey cells, I just mixed my remaining 8 cells (3.3v) with lower voltage in-between the overcharged cells and put them all in parallel. Actually, the balancing happened quite quickly, but I let them sit several hours to complete the 'saturation' of the cells which left...
  16. martyfarkle

    Overcharged lifepo4 cells: Help!

    I have assembled my broiled cells into a 24v pack and installed the OverKill (no pun intended) BMS and everything is fine as far as the cell voltage. I don't know about any capacity calamities' endured by the cells, but hooked up to my 24v inverter; it ran things fine: computer desk, hair dryer...
  17. martyfarkle

    Overcharged lifepo4 cells: Help!

    With this high over charge do I write off my cells? Is it worth even assembling them into a pack and seeing how they perform? Will it likely be that one or more will have so little capacity as to incapacitate the whole pack? I am going to use an OverKill BMS on the pack so I can keep track...
  18. martyfarkle

    Overcharged lifepo4 cells: Help!

    I have 8 more cells (3.3v? each) so I hooked them ALL in parallel, intermixing the overcharged with the 3.3v and that quickly took them down below 4 volts. I just thought of that while desperately calling local shops for a fast discharger. 10minutes later: They are now all sitting at 3.573v...
  19. martyfarkle

    Overcharged lifepo4 cells: Help!

    I overcharged my cells to 4.5v and now want to quickly discharge them so they don't hang around at that state. How can I do this safely? There is no visible distortion, no blown vents. I have no way that I know of to get them back down to a good voltage. My 12v inverter lays voltage to high; my...
  20. martyfarkle

    SmartShunt vs Voltmeter: voltage discrepancy

    Oh, wow, did not know they existed. Thanks!
  21. martyfarkle

    SmartShunt vs Voltmeter: voltage discrepancy

    No matter where I take my readings from they show the same difference between meter and shunt. And I have the shunt connected properly. Even though the suggestion that the difference is of no concern, being as finicky as I am about precision: the two devices should be much closer in agreement...
  22. martyfarkle

    SmartShunt vs Voltmeter: voltage discrepancy

    I have not tried a reading between the negative batt on shunt and the positive on shunt. I will do that later today. The meter seems right, as it measured up when reading voltage of a small power supply, though I have no real way to reliably test it; I have to trust something.... I wonder if...
  23. martyfarkle

    SmartShunt vs Voltmeter: voltage discrepancy

    I recently bought and hooked up a Victron SmartShunt. It works like a dream on BlueTooth, and I thought this would be an accurate view of my battery state/usage. For storage I have two Valence, 40ah RT Series 12v batteries hooked up in parallel. There is a substantial discrepancy in the voltage...
  24. martyfarkle

    LiFePo4 Has anyone tried this battery? Reviews.

    I assume these are Grade A? Sounds pretty low priced. Does not specify the Grade on the webpage.
  25. martyfarkle

    used 24v lifepo4 batteries.what else do i need?

    I am sort of in the same boat: I bought two used Valence 12v 40ah lithium batteries and running them in parallel. My Charge Controller is an Epever Tracer 3215BN (30A). But I am wondering if the charge controller settings are the same for 'used' batteries as for 'new' batteries. Since mine...
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