Recent content by Hedges

  1. Hedges

    Finally going off grid, need a bunch of help

    My sister said she was walking her Shepherd pup above Stanford when it froze. There was a cougar on a branch above the trail, and people passing under unaware. I've never encountered one, but a few other interesting critters on my mountain property. You only need to precharge capacitors before...
  2. Hedges

    48v 400amp ANL fuse holder?

    I doubt the plastic of a fuse holder would break down at 80V vs. 48V. Difference is likely covers to keep fingers off the conductors, for safety reasons. As you say, the fuse is was matters as far as performance vs. voltage. DC breakers - and then there is polarity. If polarized, when...
  3. Hedges

    Finally going off grid, need a bunch of help

    Having a cougar sounds like a privilege. Hopefully you can learn to just give each other respectful distance. They're supposed to be intelligent, and curious about people. Not a threat at least to adults, unless defending their cubs or rabid. Even with cubs, there's video of one making sure a...
  4. Hedges

    The "Meg" Build

    If no shade on any panels, nothing jumps out at me. Even if a bypass diode was open, wouldn't matter without shade. If shorted, you'd see a lower voltage. Can you disconnect one string at a time, see if each is similar Vmp and wattage on the charge controller? We've heard that Trina panels...
  5. Hedges

    The "Meg" Build

    In the morning, SunPower is 100V out of 121Vmp. SanTan is 90V out of 150Vtypical. 83% vs. 60% is a big difference. Any shade on SanTan? Problem with bypass diodes would be an easy to understand issue. Running half of Vmp is quite low. Low light is less current, not supposed to be that much...
  6. Hedges

    License fee to use a BMS in a project

    Patent infringement is a whole different can of worms. When HP introduced a PC running Microsoft Windows, Apple sued HP for infringing on the Garbage Can or some such IP that Apple had plagiarized from Xerox Smalltalk. Microsoft stepped in and told Apple, "If you've got a problem, take it up...
  7. Hedges

    License fee to use a BMS in a project

    If I build a house to sell, can I advertise that I installed Kenmore appliances inside it? If I sell a car, can I say it has Firestone tires? If I make an alternative energy product which happens to have a transparent cover, can I take a photo of it that shows everything visible inside...
  8. Hedges

    The "Meg" Build

    Gotta wonder why. There could be some differences in light absorbed at off-angle, but wouldn't expect 5x difference. What voltage/current are the SanTan strings delivering? Could they be outside MPPT range of the charge controller? Are the SanTan partially shaded, maybe some bad bypass diodes to...
  9. Hedges

    Trying too hard

    First get the specs and types of motor loads. Those are the hardest to start. Brush-type motors should be easier, and induction motors are most difficult. If spec includes LRA (locked rotor amps), multiply by voltage to get watts and the inverter needs surge rating for several seconds at that...
  10. Hedges

    SiO2 Silicon Dioxide Batteries

    I suspect these "lead crystal" or "silicon dioxide" batteries are lead-acid gel cell. Besides the voltages, self-discharge rate, internal resistance, I also note 0.1C float charge rate, 0.2C cyclical (it's in a graph, but not listed as a parameter.) Maybe that approaches AGM rates, a bit higher...
  11. Hedges

    Battery breakthrough for electric cars

    " ... that can be charged and discharged at least 10,000 times — far more cycles than have been previously demonstrated — at a high current density. The researchers paired the new design with a commercial high energy density cathode material. This battery technology could increase the lifetime...
  12. Hedges

    all off grid is a gamble

    12V 200Ah wired 4s3p for 48V 600Ah Cycling 25% DoD would be 150 Ah, 7.5 kWh The AGM brand I use is supposed to give a bit over 2000 cycles to 25% DoD. Some brands might be half that, some FLA much longer life. You said the loss of capacity was observed a few months after lightning strike...
  13. Hedges

    which panel to choose, 18V or 36V?

    Although I have no idea what the Kanji characters mean, I'll assume that says 36Vmp, 41Voc Two panels in series would be 82Voc at 25 degrees C. In freezing weather, voltage might increase 15%, possibly 20% depending on panels specs (only found on data sheet) But it won't reach 100V, so you're...
  14. Hedges

    which panel to choose, 18V or 36V?

    Not sure what voltage your panel really is. "36V" We need the label or the data sheet; what is Vmp, what is Voc? Summer, no tilt is good. But if you want power other seasons, consider a manual tilt.
  15. Hedges

    Trying too hard

    Sunny Island has MSRP of about $5000 more or less. But a bunch are being liquidated around $2000 or so. I bought a pallet of them through eBay. They will work with new Sunny Boy or other inverters that have frequency-watts function. You're off grid, don't need latest functions required for...
Top