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Beat

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Beat last won the day on October 22 2020

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About Beat

  • Birthday 21/07/1937

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    Dana Bay / Mosselbay

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    beatdan

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  1. Beat

    Should I wait?

    There are multiple speculations about the evolution of batteries, some with weird claims. There is no doubt that there will be improvements in technology and with respect of size and wight, including the claim of being rechargeable in minutes. But lets look into the basic physics. Lets assume an EV battery of 100kWh. To recharge it in 1 hour requires 100kW of power. To recharge it in 6 minutes would require 1000kW = 1MW. Imagine a service station on a motorway with humble 10 charge columns. That would require 10MW installed power, the power requirement of a small town. But lets look into the charge current. 1MW at 800V results in 1250A charging current. Hard to imagine what cable and connector could handle this. If I'm well informed the actual connector standard allows 25 kW. Not to mention the cell current allowance.
  2. What about settings 12 and 13? Should be 47V and 49V, or 48V and 50V. (15 cells pack)
  3. It definitely is a LEOCH 48100TB. What ticks me is that it looks like the two first delivered to me that turned out to be stolen ones. Averge told me that the black version is solely delivered to cellphone companies and used in antenna towers. Further more the fact that the name and probably the serial number have been removed is suspicious. When I learned the facts I returned them immediately to the seller. Below the picture of them. Averge then sold and delivered the civil version (clear gray) to me. Best settings are: 01: UtI, 02: 20A, 05: USE, 06: LfE, 07: ftE, 11: 20A, 12: 48V, 13: 50V, 16: CSO, 19: tEP, 23: bYE, 26: 52.5V, 27: 51.5V, 29: 42V.
  4. These optional boards are described as a necessary addition to run the inverters in parallel. The inverter can perfectly run stand alone without this board. To my surprise my MKS 5K inverters were delivered with the board installed and with the required cables despite the sellers description that they must be purchased separately for parallel installations. Therefor I have 2 complete sets of parallel boards and cables with no use. If anybody needs them, can have them.
  5. Where do you read that value? On the Inverter or on the BMS? The inverter readings are subject to the programmed voltage/SoC curve and may differ between different brands. The BMS readings also have issues as reported in my thread "Are BMS reliable?".
  6. If your adapter proves to be RS232 it could also be the inverters RS232 port at fault. I have such a case. The remote control panel to my Axpert MKS 5K inverter witch is connected via RS232, contains a presumably RS232 outlet port for computer connection. But that doesn't work. To work around I built a trow over switch into the RS232 line from the inverter. So I can direct the RS232 alternatively to the remote panel or to the computer with Watchpower.
  7. Could it be that your adapter is not a RS232 but a RS485 adapter? For monitoring my battery packs I need the RS485 adapter while monitoring the inverters with Watchpower requires the RS232 adapter.
  8. Well, batteries are aging differently depending on quality. One noticeable aging parameter is internal resistance. It is responsible for unequal charge and discharge currents on parallel connected packs. The storage capacity may also be affected by aging. On the other hand I would seriously question the reliability of the BMS readings. There is not much you can do about aging. What SoC is concerned its best to refer to battery voltage. I know that's difficult since the voltage/SoC curve is very flat. However I delegate the charge management entirely to the inverter based on battery voltage - no BMS connections. The charging failure could be due to false information from the BMS to the inverter.
  9. You have received good and intelligent answers from various competent Posters. There is however an aspect to mention: That's the energy economics. From my experience our household uses the most energy late afternoon and at night (no aircon). There will be power produced by the PVs that cannot be used and therefore wasted. The battery benefit is that it can store the solar energy harvested during sunshine and makes it available when needed later the day.
  10. Interesting. I'm also in need to replace my gate and garage door batteries. But they are 24V and the supplier in the listed link does not have such.
  11. Agree - I'm also one of them with 2x5kW inverter. And what I wrote concerning the kettle also applies to the geyser. However I pay attention not to run the geyser during LS at night. At the end of the day it all boils down to how much energy you have stored in your battery. Therefor the more battery capacity the better.
  12. There is a category of appliances however that do reduce power when reducing voltage. That are the purely resistive ones, such as heaters, cooking top, oven, fryer, kettle, geyser, etc. But I think that are not the ones you want to run during load shedding. And take the kettle for example, it would take longer to boil the water, take less current, but at the end will have consumed the same amount of energy from the battery - that is the energy required to boil the given quantity of water.
  13. Beat

    Are BMS reliable?

    Here another BMS issue: My laptop is fitted with 3 Li cells in series. Some times ago I noticed that they did not anymore get charged. The net adapter works fine as I could work with the laptop when connected. I suspected the charging circuit at fault and brought the laptop to a repair specialist. After investigation he announced that not the charging circuit is at fault but the BMS prevented charging. Since battery and BMS are an integrated unit, the whole unit must be replaced. That cost me a lot of money. I have these cells now at home and could very well charge them bypassing the BMS. I intend to use them in another application without BMS.
  14. One should not even dare to plan to use 1C discharge current. It is very damaging to the cells and creates lots of losses due to heating the cells. Size your battery capacity such that with your practical max load you do not exceed 0.5C. Battery live will reward you. Anyway the most benefit of increasing battery capacity is not the increased discharge current, but the increased storage capacity of harvested solar energy. As a side effect it increases live expectancy due to lower stress on the cells. By the way, according to my observations parallel packs do equalize themselves when reaching bulk or floating charge voltage. Provided the BMS comms do not prevent the inverter charger to properly charge up to that level.
  15. Beat

    Are BMS reliable?

    How much are the junction voltage losses?
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