Homemade LifePo4 battery

Discussion in 'Mech Tech' started by pkrboo, Mar 26, 2020.

  1. ..and being a closed unit you couldn't get in the box to measure each cell separately I guess?
    I'll double-check the BMS v voltmeter readings later when I go kick start the second BMS
     
    pkrboo and theBusmonkey like this.
  2. Yes. 4 days into my trip and still has 80% capacity. I needn’t have brought the charger.
    (Running an alpicool fridge, car stereo, and whale pump off it).
     
    Iain McAvoy, 77 Westy, Zed and 2 others like this.
  3. Happy to report BMS and voltmeter agree to with a few mV on cell charges.. now to get some current flowing in and out!
    [​IMG][​IMG]

    Sent from my SM-G973F using Tapatalk
     
    art b and theBusmonkey like this.
  4. Raspberry Pi monitoring using Victron's VRM open source software working with homemade usb connectors...

    Just need the inverter on to start using them a bit too.. half a dozen LED lights not really testing capacity ant moment fully charged on solar before 9am and they're not even on full bore yet on a cloudy day either...

    Batteries and BMS seem to be working though[​IMG]

    Sent from my SM-G973F using Tapatalk
     
    theBusmonkey likes this.
  5. Zed

    Zed Gradually getting grumpier

    Do you know how many amps your inverter gobbles just being switched on? some use up to 4 amps = almost 100ah per day.
     
  6. Not yet .. just moving existing wires out of the way to make space to mount it in the evenings! Somewhere around 1A on standby I'm told but we'll see.

    Sent from my SM-G973F using Tapatalk
     
  7. Zed

    Zed Gradually getting grumpier

    That must be a posh one! This is what you pay the big bucks for, mine's older and somewhere between 2-3A. Did you know peeps with 24oV fridges as a get round use the fridge thermostat to switch the inverter, it's that bad. Fancy having to have an extra battery or two (lead acid) just for inverter standby!
     
    Deefer66 likes this.
  8. mikedjames

    mikedjames Supporter

    My 600W inverter uses about 1.25A.
    And the Vevor £200 coolbox uses 3.5A running and 0.05A to light the LED display and run the Bluetooth even when its "off" (exactly the same unit as some £400 offerings advertised in C&B)

    And dont forger the power consumption of a Raspberry Pi.. its not zero.
     
  9. Zed

    Zed Gradually getting grumpier

    Though probably liveable compared to the inverter. Fridges are the devils work for self powered living but adding all that inverter loss to run a 240v one on top of the 4a or whatever is making me think about buying a(nother) 12V one if we ever untie from the 240 umbilical.
     

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