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FBJ

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Everything posted by FBJ

  1. That's what I thought made most sense - thanks @jumper
  2. Thanks @Sc00bs - it certainly doesn't seem relevant to use the AGM settings as a proxy for Lithium-ion BMS. So then my question is whether I have the correct settings for the BSL when it's in Lithium mode - it doesn't seem like the BMS is talking to the Sunsynk properly.
  3. Hi. I have a Sunsynk 5kW Hybrid inverter with BSL 5.1 battery. I am not sure that the inverter is correctly determining SOC as I observe it still feeding power to the battery when its apparently full - I'm seeing over 0.5kW charging when 100% SOC. I tried AGM V mode for some time and then switched back to Lithium mode. Interestingly, the moment I did that, the SOC displayed dropped from 80% to 60%. I have checked that I have the latest BSL firmware and Sunsynk firmware. CAN connection seems fine. I gather the float and absorption voltage settings are moot as they're overridden by the BMS when in Lithium mode. I find conflicting recommendation on the float and absorption voltages: The BSL Manual v1.0 says (in Victron setup example): - float: 54.8 - absorption: 55 But this page and this thread and my tech support said the opposite (for "Lithium" mode: - float: 55 - absorption: 54.8 And I was advised that for AGM mode it should be: - float: 54.5 - absorption: 54.6 Any advice, please? TIA
  4. The benefit is you get to make something off the PV power you can generate when you would otherwise have simply curtailed when your battery is full and you have surplus. See green area in bottom vs top of attached chart. Yes, the value will stack up differently for different setups.
  5. Fair point, @P1000 - that would subtract some R1.09/kWh at stated lifetime cycles (which makes it exactly match the export value! ;-). However, the value is back-ended in the extension of life so when valuing it today, with some discounting for time, it makes more sense for me to sweat the battery asset now and make it earn its payback asap. In any case, do you happen to have sight of any Sunsynk battery and export behaviour per chance? And/or advice on the correct battery voltage settings in the inverter for a BSL 5.12? (I currently have float voltage 54.8V, absorption voltage 55.0V). Many thanks.
  6. Are these the correct voltage settings @Daniemj, @Backbone Energy ? I have been unable to find any settings in BSL manuals specific to Sunsynk; however what I do see recommended in the manual for Victron is charge voltage 54.5V, Float voltage 54.8V and Absorption voltage 55.0V. What you have is the other way around?
  7. Hi. Thanks - maybe I should check the battery voltage settings. Why I want to charge battery like that is because of the relative value of the kWh (in Cape Town municipality): 1) Load: R2.40/kWh for every load unit saved 2) Battery: R2.10/kWh for load served by battery after battery efficiency 3) Export: R1.01/kWh for export
  8. Hi. I'm looking for users who are exporting to grid and have batteries with their solar PV and Sunsynk hybrid inverter. I'd like to compare how it prioritises power flow. I'm curious to see if the inability to programme the following merit order under any combination of parameters is affected by battery types: Load; then Battery; then Export Please can you advise what battery you're using and share your System1 and System2 settings page and your System Flow Chart in a scenario where your battery is not yet full and you have excess solar. If you find you are exporting and charging at the same time, then please also provide the System Flow Chart when you've turned off export. Many thanks! My example is attached. I have a BSL 5.12kWh battery:
  9. For those who may be following the original thread on whether the inverter can be programmed for merit order: Load; then Battery; then Export I have not had a resolution from Sunsynk support to date. I have been referred to the manual, which does not have a resolution and I have had suggestions that do not give this merit order. Since, as I have not had follow-up, it may mean I must infer that there is no solution with this product.
  10. Yes, I have the CT. Not meaning to be facetious, but is it possible that some clouds came by just then? That's the only explanation I can imagine from what I can see.
  11. I don't seem to have that option or its labelled differently. Might be a firmware difference.
  12. Ya, I have the manuals from here, however they don't give any useful specifics that would help with a merit order of load, battery, export. And they have errors - e.g. this chestnut, where they've jumbled the two settings up.
  13. Hi @Scorp007. Sorry to hear you only get R0.12/kWh - that's pretty dismal. I've read the manual backwards and can't see a means to set the merit order I'm looking for - would be grateful if you had a chance to refer me to the section of there is such an explanation.
  14. Thanks very much for your response, @Scorp007 . I was not aware that export was treated as load by the algorithm. If that is the case then it's unfortunate that there would be no option for a merit order that matches the value to those who have this price structure. In Cape Town, I pay R2.40 per unit and get R1.01 per unit fed back. So the merit order would be: 1) Load: R2.40/kWh for every load unit saved 2) Battery: R2.10/kWh for load after battery efficiency 3) Export: R1.01/kWh for export However, something still doesn't stack up. If it prioritises load+export over battery in Priority Load, then why doesn't it export to the maximum export limit (up to 4600W in my case) before charging? Instead it exports an arbitrary amount and charges an arbitrary amount. You can see this in the cases above (C) when Priority Load is selected and when deselected - it goes to load and then some combination of export below maximum allowable export and charge below maximum possible charge. I'm still not convinced that there's a deliberate prioritising between export and battery in the algorithm and am curious to hear from Sunsynk or be convinced otherwise.
  15. Hi again. I have tested all the combinations in scenarios when there is either an excess of available PV or less PV than loads and possible battery charge rate In all scenarios, the maximum battery charge rate is only achieved when export is disabled. With export enabled, the closest you can get to the maximum battery charge rate is when you set Priority Battery and have the Timer limit at a higher SOC than your present SOC (e.g. set it at 100%) (A). When there is excess PV, you get almost max battery, then load, then export. As SOC increases (~>50%), the battery charge rate drops off more from the charge rate you would get with export disabled. If it's possible to predict when you will definitely have excess PV and set the timer threshold accordingly, then the closest compromise you can get is (A) and then (C). The risk is (B) when there is low sun, then you get priority battery and import instead of load then battery. The following sample shows those three modes (where the timer threshold is 80%), assuming export enabled. In all cases battery charge rate would also have been higher if export disabled. In summary, I find: in all scenarios, enabling export means that the possible battery charge rate will not be maximised. There is no combination of settings that prioritise load, then max charge rate to battery, then export. Aside from when Priority Battery, and below the Timer Threshold, they will prioritise load, then split battery and export with a logic algorithm that is not clear. I suspect its a simple case of paralleling them with no prioritising. Unless someone can help me find a solution, I would suggest this is surely something that Sunsynk could improve. Thanks in advance FBJ
  16. Hi. My SunSynk 5kW inverter reduces power to the battery when I enable export to grid. I would like it to put the maximum charge into the battery before exporting. For example, with export disabled, it is charging the battery with 2kW. When I enable export it reduces that to 0.75W and exports 1.25kW. The state of charge does not make a difference to this pattern so it's not about optimising charge current. Settings in images attached. You can compare the rate of charge on a day without export and a day with export. Short of manually turning on export only after SOC is 100%, is there some logic that throttles battery charging with export that I can bypass with a setting here? Thanks in advance. FBJ
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