Recent content by efficientPV

  1. efficientPV

    Mixed solar panel angles and/or shading in series strings or parallel?

    Multiple charge controllers work well for bulk charging. I've actually found multiple charge controllers work like crap together if they can't communicate together.
  2. efficientPV

    Mixed solar panel angles and/or shading in series strings or parallel?

    It would be better if each string saw the same amount of sun ant any time to have at least one strong string. Usually about 3/4 of my 2S6P panels are shaded at any one time and I do quite well with that arrangement. It does produce power in ambient light conditions.
  3. efficientPV

    Heater Pad with MPPT, how to make it work?

    We are talking small wattages here. Depending on array voltages, you could just connect a small switching power supply to the array DC voltage to power the control and heater.
  4. efficientPV

    Freezer to Fridge Conversion: Good performance or shitty Freezer Selection

    I would not recommend that temperature control because it does not have a time delay to prevent hot starts. Any control should have a five minute delay. The timed output seems nice, but I suspect that is for total time. I have a timer in my control which turns off the inverter after 20...
  5. efficientPV

    Freezer to Fridge Conversion: Good performance or shitty Freezer Selection

    47.4F <---> 39.3F where? I find most of the newer fridges are highly stratified with cooling coils near the bottom. To make it useful at all I run mine at 34F. Even then I use a computer fan attached to one of the upper baskets. I only run in the day never discharging the battery more than...
  6. efficientPV

    ($750) Tesla Model S 18650 Battery Module

    Have any cells been clipped, the fuse wire cut?
  7. efficientPV

    I may need closely matched Marine batteries. I can only get around 12 hours powering a refrigerator.

    Keep in mind that the inverter just sitting there will consume power. I saw one video and in his refrigerator setup the inverter running at idle consumed 1/3 of the power of the entire system.
  8. efficientPV

    I may need closely matched Marine batteries. I can only get around 12 hours powering a refrigerator.

    It sounds like the real problem is you do not have enough solar or whatever source for power. When the batteries are driven down to 11.5V you are killing them. Refrigerators really need a complex control to avoid problems. Nobody makes these controls. The fallback is just bigger and bigger...
  9. efficientPV

    Energy Conservation

    I drove by a solar farm in the northeast a couple days ago and I swear the panels were set to about 15 degrees when they "should" be in the high 40's. And the direction didn't seem south, though I wouldn't swear to that. That tells me the utility would rather have flatter power all day...
  10. efficientPV

    Panels to heat a 12kw water heater

    In industrial level heating solar thermal is the way to go. I could do PV heating cheaply with a bunch of used panels because I don't use off the shelf products.
  11. efficientPV

    Dumping excess to 120VAC water heater?

    Heating water today is like when solar used relays to charge batteries. MPPT came along and everyone said who needs that technology. I swear MPPT only became popular when they figured out a bunch of panels could be strung together, connected to any battery and they didn't need to know anything...
  12. efficientPV

    battery-desulfator

    If they worked that well, the batteries would last forever on PWM controllers. That said, I restore batteries with my water heater which has high current pulses. I always need an extra battery or two and I get them from town recycling. Usually, batteries ignored over winter. The ones with...
  13. efficientPV

    Diversion loads for freezer possible?

    The arduino NANO is cheap and there is a lot that average people can do with it without really learning programming. Start with their simple boiler plate programs and add in timer functions and voltage readings. $4 isn't a lot to spend on learning something new.
  14. efficientPV

    Any inline 48v water heaters?

    Heating elements will easily fit in pipes. They need to be oriented so a bubble will never form. I think the best deal around would be used stainless hot tub heaters. Several could be linked in parallel or series and nothing wrong with using 240V elements. You should use the highest voltage...
  15. efficientPV

    Diversion loads for freezer possible?

    I use a $4 micro to run mine deciding on temperature, preventing hot starts, minimum run time, battery voltage, auto reset after 20 minutes in case something goes wrong and extended running time. Refrigerators are real battery killers. Timers and logic prevent anything from ever going wrong. I...
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