How many times did you have to cycle it to get the BMV to agree with the BMS?
I haven't done a full top-off yet. Still very cloudy here near Houston. Basically, as soon as I hit reset on the BMS, it came in line with the BMV. Fwiw, hitting 'reset capacity' in the BMS does not reset anything else, so there's no harm in trying it. In 'three bars' menu, under 'function settings' there is a button to 'reset capacity'. When you hit it, it basically tries to approximate remaining capacity. Based on voltage, I guess? Not really sure, but it does seem fairly accurate. At the moment, my bms says I have used 68 ah, and my BMV says I've used 43. We usually have good sun in December, but get lots of overcast in January, but we've been overcast here since Thanksgiving, this year. It's making it very difficult to top up. This overcast is the whole reason I wanted a big bank. I travel a lot, and take my solar with me, so I really don't want to buy more panels. Most of the year, 800 watts is more than I need:/
That's really interesting. Thanks for that, I never noticed that option before. I just tried it and it reset my capacity to 37% @ 3.28v, so still under reading for me (should be more like 65%).
So, the sun finally came out today, plus I got another 2x100 watts panels in. Sucked down 2.65 kwh today, and the battery will probably take more. It was still charging at 35 amps when the tree shadows ended my day. Battery is sitting at 13.388, having gained just .58 volt:/ Both my gauges (BMS and BMV) showed full charge hours before sunset, and the battery kept charging. So, I'm guessing that they should start counting off ah together, for the first time. It's obvious that the BMS is not basing SOC on voltage. Still, if the sun comes out again tomorrow, I'll keep trying to get my battery up to 14v. I would have thought 2.6kwh would top off my 280ah battery. Idk. This flat voltage curve and high capacity really are going to take some getting used to. I'm beginning to feel that the BMS coulomb counter may be just a rough estimate. I'll report back if I ever get the battery to 14v. If I do, I will perform a full capacity test, with a regulated load, and we'll see how accurate both gauges are.
I changed my bms voltage settings in 'parameter settings'. Reduced the values for 100%, 80% etc. It immediately altered the SOC setting, so I surmised that the SOC is based purely on voltage.
Thanks for that.
Going yo read linked article now. Thx.