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Thank you for the great forum, Safe Driving over the weekend. Sincerely Jason

P1000

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P1000 last won the day on February 12

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  1. 10mm2 is a good choice, unless you plan on running near 375W all the time, then you should go bigger and/or shorter distance. (10mm2 =~0.19V drop per 3.5m per leg at 375W) You should definitely fuse close to the battery. + to +; - to -
  2. Did you measure it with a scope, because being modified sine, the current won't be constant and a normal multimeter will probably give a pessimistic reading. The Yuasa NP45-12 that usually ship with those UPSs can do 45W/cell - 45*6 = 270W (for 10 minutes) it can peak higher than that.
  3. I have seen those elsewhere as "second life" batteries, with the same claimed number of cycles, but at 200Ah. Edit: https://www.comx-computers.co.za/SOL-B-L-M200-Mecer-Second-Life-LIFEPO4-Lithium-Battery-Buy-p-239794.php
  4. It's not quite that simple. The UPS will have a standing consumption - power it uses even when nothing is plugged in, this is likely where most of the power lost here goes. Let's call it 1A / 12W. You are using only about 6W. I don't think that for any load higher than 6W you will ever go lower in terms of efficiency (within the design limits of the UPS, which is not 600VA)
  5. 3 bit addressing perhaps. 8bits would allow for up to 256 in a stack.
  6. That seems quite likely the case - the cells are just about the same wattage 4.44W vs 4.5W, so it just depends on wiring.
  7. It most likely did take over when the meter ran out. Then used the batteries until they were empty as well. Then the power went out and your wife realized the prepaid ran out.
  8. (I am assuming this is an RCT/Mecer 2000VA UPS or similar) Well, those batteries that came with the UPS is pretty special - the Yuasa NPW45-12. It is capable of delivering 600W for 10 minutes. I don't think the replacement 18Ah would be able to do that, but they surely will be able to deliver 85A for short periods. The inverter on the other hand will not be able to deliver close to 2000VA for an extended period. It will likely do up to 800W for a short period (actually 800W is the figure written on the PCB). If you are using it to power a small load, keep in mind that it's self-consumption is about 25W. Honestly I can not understand how these are sold so cheap. You can not buy the batteries in SA for the price of the UPS (specifically the NPW45-12 - even on Amazon), and then you also get a free transformer. If someone would just go to the trouble of designing a swap-out control board that turns it into a pure sine with proper charge capabilities, you would have a winner.
  9. I was wondering that myself, but that was not really discussed in the article. Come to think of it - it must have been in a Car magazine many years ago... My best guess is that they only butcher the cell in question, and close it back up by any means - being rural Africa...
  10. I have a new favourite quote, thanks!
  11. I read an article once where they did exactly that in one of our neighbouring countries - reviving dead batteries by replacing only the cells that went bad. In order to do that you would need some donor cells, so it only becomes viable once you have multiple dead batteries.
  12. Yes, that is what I mean. To write an interfacer for emonCMS should not take more than a couple of hours. If I had an axpert, I would have written one already...
  13. What exactly does this ICC software do? I am very surprised that nobody has written an Axpert interfacer for Venus?
  14. The best would be to have a small PV panel as light sensor. And either measure it's OCV, which is proportional to the MPP, or measure the IV curve continually.
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