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TheButcher

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Everything posted by TheButcher

  1. You really should adjust the voltage your chargers are set at rather than using the BP to disconnect them even if it means calling in a friend / relative / etc. Using the BP to terminate charging is like using a hammer to put a screw in. It'll work but it's not really the right tool for the job.
  2. The Victron Battery Protect works well, but you have to keep within it's own specs. The BP is not intended to switch very high loads. People were hooking up inverters and the inrush current from the capacitors in the inverter charging up grossly exceeds the ratings of the transistors in the BP, and pretty much all FET (transistor) based protectors for that matter, and kills them. The FETs either go open, so no power, or short, so impossible to turn power off. Victron even advises that loads like inverters should not be connected to the BP, but it doesn't stop people doing it, and then blaming the BP when they kill it. Ideally the battery's own BMS should protect the cells rather than relying on something external turning the current off. Some solar chargers, such as Victron's blue / smart series, can be remotely turned off by pulling a pin on the VE.direct interface ... to +12v or 0v, can't remember which, but also with hex commands set via the serial lines on the VE.direct port. The problem with non-lifepo4/lto cells is that once thermal run away starts disconnecting the load makes no difference. It's all self sustaining. All it takes is one defective cell in a pack that draws current from its neighbouring cells, not necessarily enough to blow it's own fuse to the pack bus wire. The heat from that cell raises the temperature of its neighbours to the point where they run away, and all hell breaks loose. Watch this ... it started when just one cell failed. FYI, it's not just things like the BP that get destroyed with extreme current from inverter capacitors etc. BMSes that use FETs to switch the battery output can also be damaged. Even contactors degrade if subjected to another high current cycles. Precharging is mandatory IMO.
  3. Yikes. Glad you caught it before it got out of hand. Did you test the cells before building the pack - ie, full cycle capacity test, temperature rise during charging, resting voltage after charging, impedance test etc? Personally I'd never reuse any of the lithium chemistries that are prone to thermal run away unless I knew their full use history. Even experienced people can get caught out with cells randomly turning into glow plugs.
  4. TheButcher

    Hey Sid!

    OK, so you can be pretty much guaranteed that the flash content is encrypted so let the loader do it's thing and then ... you're kidding right? They've provided a method to interrupt the load/boot sequence? Oh my. I can see people are going to be trying that out to see if they can wander around the filesystems / memory map to get a username / salted password from the standard *nix files and presto-change-o login thankyou ma'am. Of course, firmware updates will be pushed to correct 'issues' and you won't have a choice about it, much the same as per Tesla cars. Should a username / password become available that door will be shut pretty quickly, I imagine.
  5. Same path here, one day I might cut mains but until then ... (yes, my column is the blank one!)
  6. I have no doubt that as more people move to solar the private, and government, electricity supplier / authorities will be figuring out ways to keep the money flowing in. I can appreciate that the poles and wires have to be paid for some how, but if it's a privately operated electricity network with poles and wires owned and operated by private enterprise, well, frankly, if they tried to impose a pole and wire charge on me even though I had no account with them I'd be raising hell. On the other hand in many places the network itself is government owned and operated as a common good, and in that case I wouldn't mind contributing to pole and wire maintenance, providing it was a reasonable fee.
  7. Nicer than mine too. My setup started small and simple and fitted nicely into an open frame cabinet (about 1.2m x 0.9m) but as with this sort of stuff it grew a bit. One day I'll have to take it apart and rebuild it two cabinets high. Just as a suggestion, check the voltage drop across the outputs of the chargers to the bus bars when they are pushing full current. It's more of a nicety than a requirement but with lithium's fairly flat charge/discharge curve (except at the ends) you can find that even though you have ample solar and might think that your load is being fully supported by it, you may find that you are shallow cycling your battery more than you would otherwise imagine. It's very easy to get 60mV of drop across the wire+switch+fuse (and that's just one side of the wiring, the - side has drop too) and 60mV of shift in voltage for a lithium battery represents a fair amount of capacity. Your chargers will attempt to keep their terminals at the configured voltage and will only supply enough current to do that. Until the battery discharges down far enough to exceed the total voltage drop from your wiring etc your chargers will never go 'all in'. Chargers with remote sensing don't have this problem since they see the far end voltage and attempt to hold it at their set voltage compensating for the drop through the wiring etc. I'm not a micro-cycle nutter that thinks the world will implode if you do it, but you may find that you are pushing your batteries through 15% DOD cycles so it's food for thought.
  8. You could take a miniport driver from NT3.5 and install it on NT4 and Windows 2000 too. The layers above, and below the driver would recognise that the driver didn't import / export certain hooks / functions and not try to use them. Cutler really did his homework when the basic framework of NT was penned.
  9. It has the potential to fry the charger if the charger is poorly designed or uses substandard components but even the MakeSkyBlue chargers are good enough to survive, and trust me, I've deliberately tried to kill a MSB by winding it up to full current and disconnecting the battery. The bigger risk here is to your load electronics. If your loads stay connected to the charger, and there is high current from the charger and the battery spontaneously disconnects, there can be a huge spike in the output voltage and that will damage or outright kill voltage sensitive electronics. Most of the chargers I've come across, I'm not sure about the MSBs, have transient protection on their output to clamp the voltage to some safer level. There is a weakness here in that for chargers that support multiple battery voltages, say ranging from 12V to 48V, and have simple single diode clamp the protection has to be greater than the maximum battery voltage so for a 48V battery that will mean over 56V (full charge voltage). A 12V electronic device hit with a 56V spike isn't going to have a good day. I haven't tested a MSB V119 charger, but V117 chargers tend to go a bit loopy when the battery disconnected with their output turning very noisy and voltage flitting around all over the place. I wouldn't like to subject any of my loads to that.
  10. React is a nice idea but I think I'll be dead from old age before they get to a release version and TBH WINE on *nix will meet most people's needs to run a Windows program without Windows. IMO Microsoft releasing the source code for anything close to a current version of Windows would only happen just before they drop Windows. perhaps moving to a compatibility layer in linux etc. 'Next' versions of Windows aren't built in a vacuum. It's an evolutionary process rather than revolutionary, to the point where a vulnerability found in a current version of Windows has a pretty high chance of existing in a discontinued version if that vulnerability isn't in some truly new thing that didn't exist in any form in the old version. Releasing, say, Windows NT3.1 source code would still give away far too many secrets, methods and concepts that exist today in Windows 10.
  11. From what I've seen even the elcheapo chinese HF inverters have internal fuses. Sure there's still scope for a wiring fault inside the inverter between the DC terminals and the fuse on the PCB but I think you are pretty safe there. Personally I wouldn't run without protection between the busbar and inverter, and at the busbar end of the wire too. Accidentally shorting the leads with a wrench while fitting to the inverter may require a change of underware and a new set of eyes.
  12. How many cells in parallel are you talking about? I'm assuming this is a build using cylindrical cells.
  13. The original RISC concept was a rigid simple ISA specifically intended for high instruction throughput and easy parallelism resulting from the much simpler design of the execution unit. Instructions generally execute in a single clock cycle once all the data is available. Memory accesses are all aligned with the native bit width of the CPU, 32, 16, 64 bits etc. All the massive amount of silicon that current goes into parallelising and optimising (out of order execution and that ails it, hellllo spectre etc) the x86 ISA is not needed. Even the current ARM ISA is bloated by genuine RISC standards. The heavy lifting of code optimisation and parallelisation was moved to the compiler where it could evolve and develop without changes to the silicon. Anything CISC can do RISC can do too, and vice-versa. The difference in performance comes down to the hardware and software engineers.
  14. Everyone knows Windows is better. Is there a version of linux with gardening support? Nope. Windows NT has support for gardening built right in with its Dynamic Hose Configuration Protocol.
  15. Always interesting to see how things were done in another country. Long haul passenger trains in my state, QLD Australia, weren't air-conditioned at all until 1953 when a new set of diesel hauled trains replaced the old steam hauled wooden carriage trains that only had fans. The new train had a dedicated generator car that provided 240/415 50Hz AC. That set ran until 2014 when they were replaced by a tilt train (diesel and electric versions depending on where in the state it runs) that is permitted to run up to 160km/h on QLD's narrow gauge track.
  16. Based on the pictures and footage there is no chance of it doing 1200W. Zip. The temperature rise would exceed the maximum junction temperature for the transistors before Vmp could be found. Active cooling would work if there is a temperature sensor involved, but if it's just computed temperature rise values, no chance. For what it's intended, testing of most common panels to see how they are travelling or before installation, it does the job well enough. In real terms, just how quickly can you disconnect a single panel from an array, connect the meter, test, reconnect panel to array anyway. It'd take me at least a minute to fish the wires out from under an installed panel, then another minute to undo the MC4 connectors, and that'd be rushing it.
  17. It comes down to form factor. With the width of the box and the space for the screw terminals being the limiter. The readily available cheap (and let's face it, MSB isn't targetting the premium end of the market) '6 amps' terminal blocks in this style come in various configurations up to 16 contacts. Different pin (on the circuit board side) spacing is available but you give with one hand and take with the other, the spacing means less terminals, blah blah blah. MSB has decided that using 2 x 2 and 2 x 3 blocks is the cheapest way for them. They could have used a single 10 contact 6A strip but they cost more. Fork your single cable into two smaller bundles of wires and put one into a separate terminal. These things are absolutely made in China. Makeskyblue is a Chinese company, and don't attempt to hide that at all. The faker brand powmr that makes a clone of the MSB charger says what ever they can to get the sale, including running ads that state Makeskyblue is the fake, as well as ads saying powmr is a registered name in the USA (might well be, but has nothing to do with them being a faker that also makes stuff in China). Did you by a powmr branded one?
  18. The terminals? It's the same as the others. At least the 40A (v117) and 60A (v119) units I have here are identical on the terminal strip. PV+PV+, PV-PV-, BAT+BAT+, BAT-BAT-, OUT+, OUT-
  19. Old capacitors aren't necessarily faulty capacitors, but it's probably a safe assumption with anything PJ uses. Victron had a discussion about AC side induced DC ripple and recommended that if you see more than 200mV (I think) peak ripple on the inverter's DC input under full load you need to improve the wiring and/or battery capacity but, by extension, if both those are good enough for the load it's time to look at those capacitors.
  20. My Bosch front load washing machine reacts to significant voltage reduction by stopping the drum for a few seconds (until voltage recovers) if it happens to be rotating at the time. I found this out while trying to provoke the nasty trace I posted in the off topic section of the forum. It may also stop water heating, but that's much harder to detect.
  21. I haven't seen demand reduction on a washing machine before, but you never know what is really inside the box until you look. A washer that can heat the water may well have it. The standard is generally referred to as DRED (nice acronym) here but the underlying signalling is up to the particular electrical authority. It seems to be ripple on the mains in my state, but others have trialed 3G mobile (cell) phone comms. Basically anything goes so long as the manufacturer is prepared to support it. PLC, Zigbee, you name it. Mostly I've come across it with airconditioners so checking what signalling aircon uses (if any) in The Blind Wolf's area would probably be a good search to start with.
  22. The manual for the machine isn't so useful, at least the ones I found, but it really makes me wonder if the unit has power reduction signalling support (describe it as you like), ie it can take cues from the electricity supply to lower its demand in response to the electricity company saying 'throttle back', to moderate high power network utilisation / shortfalls.
  23. Just pay attention to what you are buying. Signs of tarnishing on the cells / interconnecting wires / busses is usually an indicator that moisture has made its way into the encapsulation. The panel may last for years more, it might fail, and possibly catch fire, tomorrow. If the clear encapsulation has crazed / cracked, like broken safety glass panes, edges, it also has moisture problems. Trina had a lot of panels go crook due to problems with the back sheet and ingress around the edges. You can buy them by the pallet load cheap in the USA, so be aware of that issue with them. Panels with moisture ingress go electrically leaky to the frame and that might be enough to trip protection devices and can certainly be a hazard to a person with high voltage strings.
  24. GS Inverters, so tough that even UPS can't break 'em. Please send payment for use of slogan to TheButcher c/o genetrysolar forum 😉
  25. Don't forget that your actual battery voltage comes into play, not just the nominal. I think you are using lifepo4, so your battery will be lurking around 25.5 volts and higher unless you discharge it fully. At 25.5V 60A is 1530W. At 26V, 1560W and 27 1620W. 1300W is 50A at 25.5V.
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