Search results

  1. Sverige

    Anyone know a good smart home forum?

    Hi, I’m trying to get up to speed with how to use a XiaomI smart home hub I’ve bought and have a heap of reading to do and questions to pose, as smart home control products are their own world and off topic for this forum. Does anyone who is onto this stuff know where the smart home equivalent...
  2. Sverige

    Externally controlling a non-controllable charge controller

    It seems it’s mostly the more expensive charge controllers which make provision for external enable / disable control via a closing contact. What all of the cheaper charge controllers seem to have in common though is over temperature protection which shuts off charging when the internal temp...
  3. Sverige

    Connecting off grid inverter to house wiring

    Is it ok to permanently join neutral from an off grid inverter to neutral in house wiring distribution board, then switch individual wiring circuits between the inverter live and mains live (with an intermediate ”off“ position, so power doesn’t switch directly from mains to inverter without a...
  4. Sverige

    Connecting off grid inverter to house wiring

    If considering connecting a generic cheap off grid (not grid tie) inverter to house wiring, would it be safe to make a permanent connection between inverter neutral and house (mains) neutral and then just switch the live lines? In this case, the inverter neutral would always float at the same...
  5. Sverige

    LiFePO4 accessories supplier within Europe?

    Does anyone know of a stockist who might sell suitable busbars for 272Ah Lishen cells “off the shelf” within the EU? Or is everything of those nature shipped from China / HK? I have 4 cells and currently no busbars and looking for the cheapest way of solving this problem. I was looking into...
  6. Sverige

    Switching 220V mains with sonoff relays

    I’ve bought two of the 4 channel Sonoff relay sets and would like to use them to switch the output of my inverter to various load circuits. The load circuits will he switched between inverter and grid mains, so I need to be careful everything is double safe. The sonoff relays are rated to 240v...
  7. Sverige

    Moving house load circuits to switchable inverter output feed

    I’d like to make use of my off grid inverter (220-240V single phase AC) to power some circuits in my house on a switchable basis, ie. only switched on once in a while when I have enough accumulated solar power in battery. The rest of the time these circuits will run mains from the standard...
  8. Sverige

    DC/DC converter module efficiency testing

    I ordered a few different types of DC/DC converter modules from amazon all of which had vague specs like “up to 95% efficient“, so I started to wonder how efficient they really were in the application I wanted to use them in. All work in a similar way - you connect a DC voltage at the input...
  9. Sverige

    This is not a complaint! It’s a suggestion

    I love the clear categorisation in this forum and find that almost everything is covered, but there’s one thing which I consistently find difficult to place into any of the sub-forums, and that’s maybe best described as “general electronics” or maybe “DIY electronics”. We have sub-sections for...
  10. Sverige

    Weak cells vs runners

    I see the term “runners” being used to describe some underperforming cells, but but other times “weak cells” and it’s clear from the context that they’re two different things. So what is a runner and how is different from a weak cell?
  11. Sverige

    “Normal” self-discharge rate

    What’s a normal rate at which LiFePO4 cell voltage settles, fresh off charge? I have four cells which were charged to a 3.6V cutoff, and within a few hours they‘ve settled to 3.37V and still slowly declining. Is this normal, or excessive self-discharge? They’re prismatic 100Ah cells. One cell...
  12. Sverige

    Electrodacus SBMS40 3D Brothers Edition Review Thread

    I’ve received one of the new “3D brothers edition” Electrodacus SBMS40s from the prototype batch, as offered forum members for review purposes recently by Alex Gradea. It’s not clear to me right now what, if any changes might feature in the production batch of units, so for now I’m assuming...
  13. Sverige

    Mobile app for drawing PV schematics

    Does anyone know of an iOS app which can be used for easily drafting electrical schematics including the components we use in Solar systems? So PV panels, charge controllers, shunt, BMS, battery, etc... I have an iPad Pro, so plenty of screen space to draw on, but instead of trying to sketch...
  14. Sverige

    Stackable 18650 boards - why do people use them?

    I’ve been looking at some of the stackable 18650 boards which are sold complete with battery clips, so you can assemble a board and add 14 x 18650 size Li-ion cells for a 7S2P arrangement per board (boards are double sided). Here is an example and here is an assembly video in case it’s not clear...
  15. Sverige

    Renogy 100W panels - how are they split?

    I’m looking at these 100w panels from Renogy, and the specs say 2 bypass diodes, guess the cells within the panel are wired in 2 strings, but how are they split? The cells within the panel are 3 x 11, so no obvious split vertical or horizontal. I’m wondering whether to orient them landscape...
  16. Sverige

    24V inverter typical input voltage range

    Is there a typical input voltage range for a small 24V inverter, maybe 500W to 1000W pure sine? I ask because I’m having trouble finding specs on many product listings, they all just say “24V DC nominal”. I’m trying to work out if I could run such an inverter from a 7S LiFePO4 battery (instead...
  17. Sverige

    Balancing cell capacity in DIY LFP batteries by adding smaller cells in parallel

    Ok, this may constitute heresy even asking this question, but here goes anyway! :LOL: Given that the weakest cell in a series pack dictates the overall battery capacity (as it reaches LVC soonest), is there anything to prevent the DIY LFP battery builder balancing out cell capacities by adding...
  18. Sverige

    Added second panel in parallel and total power dropped!

    I have a pair of identical PV panels from solarv.de and have them mounted both facing due south, but around 10m apart. Specs are below Technical data: rated power (Pmax): 160 W, max. Voltage (Vmp): 18.1 V, max. Current (Imp): 8.85A -- Open circuit voltage (Voc): 22.32V -- Short circuit...
  19. Sverige

    Does anyone recognise this cell?

    Could anyone tell me who the manufacturer of this 100Ah cell might be? 🕵️‍♂️
  20. Sverige

    What’s the name of this style of mounting clip?

    Hi, simple question for you! What’s the name of this type of mounting clip, which can be used to secure a panel? I need to buy 4 of them, but don’t know at present what search term to begin searching for! Also, if anyone should happen to know an economical source of parts like this within...
  21. Sverige

    Making best use of buck/boost DC/DC converters

    I’m planning on using generic, cheap LM2596 DC/DC converters to drop my DC bus voltage from around 14V (4S LiFePO4) to the 12V, 9V and 5V my devices will require. All load devices are very low power, around 3W continuous will be drawn from each of the voltages (5, 9 &12V), so well within the...
  22. Sverige

    Successful de-sulfate / equalisation of lead acid batteries

    I thought I’d record the process I have recently followed to improve the performance of a couple of lead acid car batteries which I’ve been using in my off grid set up. Unfortunately I didn’t measured the capacity or internal resistance of the batteries before and after, but I can see that my...
  23. Sverige

    Calculating cable power losses

    I watched an interesting video yesterday, which @gnubie posted In this thread. Today I got to work calculating the power losses in my cabling from panel to charge controller and actually ended up installing a second cable in parallel as a result. My current set up is a 160W poly panel which...
  24. Sverige

    Help needed choosing MPPT charge controller

    I’m hoping some of you can help me find a good candidate to match my needs, which I would list as follows: - Affordable 40A MPPT charge controller (under $200) - Can handle my array of 2 x 160W poly panels in parallel (18.1 Vmp). Partially shaded location, hence parallel connections - Can...
  25. Sverige

    Parallel controllers between a single panel and battery

    Take one solar panel, connect it with a cable to the inputs of two PWM solar charge controllers in parallel, then connect the outputs of those controllers in parallel to one battery. So one panel, one battery and two current paths between the two, via two different charge controllers. Leaving...
  26. Sverige

    Why programmable controller for prismatic cell battery?

    From 9:28 - 10:00 in this video, Will explains that for systems using a custom LiFePO4 prismatic cell battery, a programmable MPPT controller is required, because you will need to set a custom upper voltage limit instead of using 14.4V which the “out of the box” lithium compatible controllers...
  27. Sverige

    Parallel connection of panels with very different sizes

    I have a question about connecting panels in parallel. I understand their capacities are added to one another and if they have similar characteristics (peak voltage?) then there’s no downside to doing it. But what if one panel is shaded, does it degrade the performance of the panel which is in...
Top