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  1. R

    What's the difference between charge controller and buck converter? For microgeneration

    You can't have 4.15V but only 3.95V, the two points have a copper wire joining them & they would & should be the same! re buck converters vs MPPT charge controllers, it's not only the efficiency & voltages, it's about the load on the input side. Ie if the voltage going into a buck converter...
  2. R

    In-situ 18650 heater cell detection

    Maybe using the same adhesive pad stuff (eg on the flat side of the DS18B20 TO-92 package), sticking to the side of one cell? Could be placed using a timber strip? Would be easy during the pack build & yes, more fiddly later! Another position might be at the bottom (-ve end) of the cell as...
  3. R

    In-situ 18650 heater cell detection

    +1 for the one-wire DS18B20 devices. Readings might be better with the sensor half way down the side of the cells ie between 4 cells but one sensor could likely sense in the middle of a block of eg 16 cells & give useful data on trending heat build up.
  4. R

    10mm diameter cables should be OK. 10mm squared cables (cross section area) might be under...

    10mm diameter cables should be OK. 10mm squared cables (cross section area) might be under sized. The inverter may be faulty?
  5. R

    "I installed 2 new batteries 12v 100 amp, but still with error 52" Is your wiring thick enough...

    "I installed 2 new batteries 12v 100 amp, but still with error 52" Is your wiring thick enough? If you have thin cables or a bad connector, you may get errors like this.
  6. R

    Reviving an undercharged BYD 11kWh pack

    Is there a way to tell the BMS SoC is now eg 50%? Maybe put some current through the shunt so it registers rising SoC?
  7. R

    Mounting 18650 cell packs on DIN rails

    Other types of rail might also be cheap, widely available but stronger, eg unistrut...
  8. R

    Question about making a battery

    +1 to Korishan & OffGrid's posts above. Also note that the higher you make the system voltage, the lower to current you need to pull from the batteries. But even with a 48V system, laptop batteries (as explained well above) likely won't work well for you. You need "high discharge current" rated...
  9. R

    batterywall designs

    Yes any battery pack you make needs to be properly electrically insulated but you'll find over wrapping them is not really helpful. For trailer use, you also need to consider vibration & movement. Maybe make robust smaller packs & link with flexible short cable links vs stiff bus bars. Re the...
  10. R

    batterywall designs

    To clarify, are you: - trying to build an electric car powered by lithium cells? - trying to build a starter battery for a regular petrol, etc engine car ? - trying to power other devices in a vehicle & recharge from the car's 12V system? As Korishan & others have said above, lithium Li-ion...
  11. R

    Always with the questions. This time grounding.

    Sorry for the late reply, been away... Below might have been covered already.... What you're saying can be true for "normal" voltages but there's two conditions where hazards occur: - fault conditions that cause something to be at an unsafe elevated voltage, human touches something, gets shock...
  12. R

    Always with the questions. This time grounding.

    Here in Australia, regs are the panel frames & rails are all bonded together & tied to the house ground. Panels are supposed to have special washers/shims that pierce the anodizing & ground cables linking between them all (mine do). I think it's similar in the US but not sure. With lightning...
  13. R

    What battery voltage 24 or 48 volts ?

    Korishan's info above is good. If you are only using about 3.5kW/day, your usage sounds lower & a 24V system might suit better for other reasons. With 24V systems, the battery & BMS parts are a bit simpler but wire sizes go up (due to higher currents at 24 vs 48V for same power out). 24V may be...
  14. R

    First steps, and some questions...

    At those power levels, you should go straight for 48V to avoid losses. Either battery type is fine, but the LFPs will probably last longer & like you say are more stable chemistry. Don't know about the MP functionality, sorry. Yes, for 3 phase, the inverters are linked & configured to operate as...
  15. R

    Did anyone see this...

    Both videos do say electrons do move, they just don't have to move far for AC or DC currents to flow. AC they move back & fwd, DC they trickle slowly in one direction. +1 batteries it's about changing the chemistry, ie a chemical reaction stores/releases electrons. For capacitors (two close...
  16. R

    Did anyone see this...

    OK, agree from a physics point the first video is OK as edited in my post above above. As the EEVBlog video points out at about the 15min mark, practical engineering for DC & AC mains mostly doesn't need to worry about the physics & fields. Question: what happens if the wires are removed? (not...
  17. R

    Did anyone see this...

    So this guy is contradicting major physics? EDIT: I should be saying practical engineering, physics he's quoting is OK, except Atlantic cable issue. There's some serious misrepresentations & knowledge gaps in that video: - "no continuous flow of electrons from a power station to your house... "...
  18. R

    Did anyone see this...

    At radio frequencies & even a little bit at mains AC 50/60Hz things get much more interesting. I've been in a room with fluorescent lights "on" when the light switch was off (at a radio transmitter site back in the day, not sure that'd be allowed today!. Look up waveguides, eg in your...
  19. R

    SimpBMS Tesla State of Charge

    Yes, setting SoC by voltage would be an initial starting point, then like Tom said, it's current counting ("coulomb counting"). + other above settings needed too.... But seemed like you were asking how to figure out your battery bank's capacity & then getting that into your SimBMS's capacity...
  20. R

    DIY 230v/2kw HV inverter

    Not sure, sorry. Might be (marginally) less dangerous if you were making each half sine with an inverting (-ve) & non-inverting (+ve) buck or flyback topology directly in the first "stage". Even if you've got experience/qualifications with HV stuff, only then a very cautious maybe for one test...
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