Jesse

Thanks Coulomb Yes, not the AC in :-). I currently have a 100A fuse between my batteries and the inverter, no isolator [see attached]. Can I use this for 6kWh of Li-Ions? Regarding the monitoring, if it's only monitoring, as long as it works I'm ok with knowing less, but would it impact the performance or longevity of the system?

HI GUYS! I followed Coulomb's previous suggestion in this thread and added 3 more panels to my system and now would appreciate some help with increasing my battery storage. As an update, here's my current Off-The-Grid system: Mecer SOL-I-AX-3MPlus48 Inverter/Charger 6-300W Enersol panels X 4hrs=3600Wh[Watt hours] X.8=5760Wh power potential per day 4-12V 100amp/hour AGM Vision 6FM100LP-X batteries hooked in series=4.8kWh storage potential [2.4kWh usable at 50% DOD] Yamaha EF5500FW Generator My batteries are about 4 years old, and although they still seem to be working well, I understand the reasons not to just add more AGM batteries, and I am leaning towards Li-Ion batteries, so: Firstly, could someone confirm that my figure is right regarding my current usable battery potential of 2.4kWh? Secondly, what size the equivalent Li-Ion battery would need to be to double that usable storage capacity [assuming 80% DOD=6kWh?]? Thirdly, what can I do with the old AGM batteries [put in a switch so that I could use them instead of my generator as a backup]? And finally, do I need anything other than the actual Li-Ion battery with my configuration, noting that I currently don't have any extra monitoring software, and would prefer to keep it simple. And would brackets or anything else be necessary? thanks Jesse

Not much response on this one, so I put in another 10 hours of web hunting and found this site that gave me exactly what I needed: https://pvwatts.nrel.gov/pvwatts.php hopefully it will help others as well, no matter where in the world they may be 🙂

PS After posting this I found the following website: https://solarcalculator.com.au/solar-panel-orientation/ which tells me that I would lose 15% efficiency if pointing east [since Sydney and Swellendam have the same latitude]. This would seem to indicate that a northeast orientation would likely result in only a 7 or 8% loss. It also mentions that if not facing north a more horizontal tilt would give better performance, and I do have a porch roof just below my existing panels that is only 12% that would seem to be a better location. Any comments and/or suggestions on the above?

I have three 300W solid panels installed directly on normal minirails on a 34 degree roof pointing directly Northeast in Swellendam [latitude 34 degrees]. I want to add some new panels and could put them on special rails that orient them to the north, but I hesitate doing so because of cost, aesthetics and extreme wind conditions. In order to make a more informed decision regarding the cost I would like to calculate the efficiency loss from orienting any panel to the Northeast vs directly north [assuming the same tilt]. I've looked on the web, but only found generalizations saying that it's better to point them north, and that a few degrees off won't matter much, but no hard calculation that can determine the difference if 45 degrees off of north. Can anyone help me with this?

Thanks Coulomb - thanks very much for all your help!

Wow - thanks Coulomb - very helpful! I am especially grateful for helping me to understand the reasons for it all. Regarding changing my charge rate from 20A to 15A. I didn't give the exact specification's of my batteries, which are 100amp/hour AGM Vision Pure Lead Long Life Series, rated at 30A maximum charging current. Chris recommended 20A, saying that this setting was covered in previous posts, but I couldn't find the posts? Do you still recommend reducing it to 15A, or would it be better to go up to 30A? And I'm not sure where I got the suggestion to change the bulk and float settings with the seasons, but would you agree with what I am setting them at for Swellendam, where the average midday temperatures range from 17.1°C in July to 27.5°C in January [although a couple times of year it reaches 40]? Your suggestion to add panel(s) confirms my thoughts, so I am going to add another series of 3 - 300W panels and hook the new set up parallel with the first set. Are there any settings I should change when I do this?

HI GUYS! I started this thread about 8 months ago and got some great advice [mostly from Chris] that has worked well, but as winter approaches I am needing to use the generator and have a couple questions/concerns that I would appreciate some help with. As a reminder, my current and very small Off-The-Grid system: Mecer SOL-I-AX-3MPlus48 Inverter/Charger 3-300W Enersol panels X 4hrs=3600Wh[Watt hours] X.8=2880Wh power potential per day 4-12V 100amp/hour Vision batteries hooked in series=4800Wh storage potential [2400Wh at 50% SOC] Yamaha EF5500FW Generator Current settings, as suggested (with a ‘?’ where it’s a strange looking letter 🙂 : 01, U?I [Utility first] 02, 20A [Maximum charging current] 03, UPS [AC input voltage range] 04, SDS [Power saving mode disabled] 05, USE [Battery type] 06, L?E [Restart enable] 07, ??E [Restart enable] 09, 50Hz [Output frequency] 11, 15A [Maximum utility charging current] 12, 48 [Irrelevant, since I have selected U?I in Program 01] 13, 54 [Irrelevant, since I have selected U?I in Program 01] 16, CU? [Charger source priority] 18, BOF [Alarm control] 19, ?EP [Auto return to default display screen] 20, LOF [Backlight control] 22, LOF [Beeps while primary source is interrupted] 23, BYE [Overload bypass] 25, FEN [Record fault code] 26, 57.6 in winter & 56.1 in summer [Bulk charging voltage] - Swellendam, Western Cape 27, 55.2 in winter & 54.2 in summer [Floating charging voltage] 29, 42 [Low DC cut-off voltage] Questions: 1) My green charging light goes from flashing to solid even when the charging icon shows only two bars, and although I know that it would help to purchase a Victron Battery Monitor, I cannot afford one right now, and would like to work with what I have. I do have a voltmeter, and testing the batteries confirms that the Mecer voltage reading is pretty accurate. Should I ignore the bars? 2) The inverter’s specs on the side of the machine say: AC Charger Mode: AC Input 230VAC, 50Hz, 17.7A, 1o DC Output 54VDC, 10A/15A AC Output: 230VAC, 50Hz, 13A, 1o When using the generator I am connecting its 17A outlet to the Utility connection on my inverter. Does the inverter then charge the batteries at 54VDC & 15A? How do these numbers relate to my #26 [57.6V] and #27[55.2V] program settings, noting that when I charge the batteries with the generator at night the battery voltage goes up to over 57V, and when the generator goes off, pretty soon settles to about 52V? Do I have the right settings for this generator - especially for charging? Assuming a 50% SOC [48V], how long should it take to fully charge my batteries with only the generator? Is there any charging advantage to leaving the generator on for a period of time after it has reached the bulk setting? Is there any way I can get more charging power out of my generator, since it's already running and only using a fraction of its potential, like adding a separate AC charger? 3) Usually whenever I have the generator on or a load of more than about 210W the fan goes on, but I recently noticed that when the generator is on and the green light goes solid, even with a load greater than 210W, the fan repeatedly cycles off for about 10 minutes and then back on for about 10 minutes, showing that a silent fan is possible :-]. The inverter is in our living room, and there is only one daily load that triggers the fan – our fridge at 220W. Is there any way I can change when the fan goes on by just a little bit, noting that I hardly ever feel any heat from the top heatsink? 4] In my manual, the Display Settings for the MPPT Charging power show PV, BATT, and W [as well as OUPUT in V], but my actual display shows PV, INPUT, and W. And mid-day this can go from 130W without a load to 330W with a large load. Does this make sense? Again, any help is much appreciated.

That makes sense - thanks!

Thanks for the heads-up, and it took me a while to look into this, but isn't this only relevant to grid-tied systems?

That makes sense, thanks!

Hi Tripletts - Yes, we're in Swellendam. Hi Chris - Great!!! With program 11, the maximum it will let me go to is 15A, but my Yamaha EF5500FW is only rated at 17.3A [3.8KVA], so not too much potential lost. With regard to #29 remaining at the default 42V - as you mentioned with regard to #12, with my small battery bank a large load causes significant voltage sag - so it seems that if set much higher it would reach cut-off prematurely, and yet someone here said it should be set at 48V to preserve the batteries, so is there anything more you can say on that one? Everything else makes sense and the suggestions and explanations are very much appreciated - I've already changed the settings and will see how she runs :-).

Wow - Thanks Chris! I'll leave #1 & #4 above as they are, and if after looking at all the settings you still suggest changing #27 to 54V, I will do so [#2 above]. You have also suggested changing #13 to 54 or 55V [#3 above]. Could you explain how that differs from 'Battery Fully Charged', and I don't understand your reason, as there is no grid to charge the batteries [only a manually started generator that I may never use]? Regarding the Battery Monitor, I am moving my inverter to a more remote location [too noisy in the living room], and so I do need a remote battery voltage monitor [so that I can see whether it's ok to use the electric kettle :-], but wasn't planning on spending R2000 - how necessary is this item, as I don't currently monitor anything other than voltage? Regarding the battery balancer, am I correct that I would only need one HA02 for my system? In once again looking over the settings, one thing that seems to make sense is to change #3 to UPS? The other one that is questionable is #29 - as I believe 42V, even though it is the default setting, is a completely drained battery? [Note that despite this, after 2+ years a load test shows they are still in good shape, and I always check the voltage before I run the kettle, so it rarely shuts off.] Again - thanks so much for your help, and here are my current settings in red. Setting Programs: Program Description Selectable option 00 Exit setting mode Escape 01 Output source priority: To configure load power source priority Solar first Solar energy provides power to the loads as first priority. If solar energy is not sufficient to power all connected loads, battery energy will supply power the loads at the same time. Utility provides power to the loads only when any one condition happens: - Solar energy is not available - Battery voltage drops to either low-level warning voltage or the setting point in program 12. Utility first (default) Utility will provide power to the loads as first priority. Solar and battery energy will provide power to the loads only when utility power is not available. SBU priority Solar energy provides power to the loads as first priority. If solar energy is not sufficient to power all connected loads, battery energy will supply power to the loads at the same time. Utility provides power to the loads only when battery voltage drops to either low-level warning voltage or the setting point in program 12. 02 Maximum charging current: To configure total charging current for solar and utility chargers. (Max. charging current = utility charging current + solar charging current) Available options in 1KVA 24V and 1KVA/3KVA 48V models: 10A 20A (default) Available options in 2-3KVA 24V models: 20A 30A (default) Available options in 2-3KVA 24V/48V Plus and 4-5KVA 48V models: 14 10A (Not available for 2-3KVA 24V Plus) 20A 30A 40A 50A 60A (default) 03 AC input voltage range Appliances (default) If selected, acceptable AC input voltage range will be within 90-280VAC. UPS If selected, acceptable AC input voltage range will be within 170-280VAC. 04 Power saving mode enable/disable Saving mode disable (default) If disabled, no matter connected load is low or high, the on/off status of inverter output will not be effected. Saving mode enable If enabled, the output of inverter will be off when connected load is pretty low or not detected. 05 Battery type AGM (default) Flooded User-Defined If “User-Defined” is selected, battery charge voltage and low DC cut-off voltage can be set up in program 26, 27 and 29. 06 Auto restart when overload occurs Restart disable (default) Restart enable 07 Auto restart when over temperature occurs Restart disable (default) Restart enable 08 Output voltage (only available for 2KVA 24V/48V Plus 120Vac models) 110V 120V 09 Output frequency 50Hz (default) 60Hz 15 11 Maximum utility charging current Available options in 1KVA 24V and 2KVA 24V Plus 120Vac model: 10A 20A(default): Available options in 2-3KVA 24V and 2-3KVA 24V Plus models: 20A 30A (default) Available options in 1KVA/3KVA 48V and 2-3KVA 48V Plus models: 10A 15A(default): Available options in 2KVA 48V Plus 120Vac model: 5A 10A(default) Available options in 4KVA/5KVA 48V models: 2A 10A 20A 30A (default) 12 Setting voltage point back to utility source when selecting “SBU priority” or “Solar first” in program 01. Available options in 24V models: 22.0V 22.5V 23.0V (default) 23.5V 24.0V 24.5V 25.0V 25.5V Available options in 48V models: 44V 45V 16 46V (default) 47V 48V 49V 50V 51V 13 Setting voltage point back to battery mode when selecting “SBU priority” or “Solar first” in program 01. Available options in 24V models: Battery fully charged 24V 24.5V 25V 25.5V 26V 26.5V 27V (default) 27.5V 28V 28.5V 29V Available options in 48V models: Battery fully charged 48V 49V 50V 17 51V 52V 53V 54V (default) 55V 56V 57V 58V 16 Charger source priority: To configure charger source priority If this inverter/charger is working in Line, Standby or Fault mode, charger source can be programmed as below: Solar first Solar energy will charge battery as first priority. Utility will charge battery only when solar energy is not available. Utility first Utility will charge battery as first priority. Solar energy will charge battery only when utility power is not available. Solar and Utility (Only available for 4KVA/5KVA model) Solar energy and utility will charge battery at the same time. Only Solar Solar energy will be the only charger source no matter utility is available or not. If this inverter/charger is working in Battery mode or Power saving mode, only solar energy can charge battery. Solar energy will charge battery if it's available and sufficient. 18 Alarm control Alarm on (default) Alarm off 19 Auto return to default display screen Return to default display screen (default) If selected, no matter how users switch display screen, it will automatically return to default display screen (Input voltage /output voltage) after no button is pressed for 1 minute. 18 Stay at latest screen If selected, the display screen will stay at latest screen user finally switches. 20 Backlight control Backlight on (default) Backlight off 22 Beeps while primary source is interrupted Alarm on (default) Alarm off 23 Overload bypass: When enabled, the unit will transfer to line mode if overload occurs in battery mode. Bypass disable (default) Bypass enable 25 Record Fault code Record enable Record disable (default) 26 Bulk charging voltage (C.V voltage) 24V model default setting: 28.2V 48V model default setting: 56.4V If self-defined is selected in program 5, this program can be set up. Setting range is from 24.0V to 29.2V for 24V model and 48.0V to 58.4V for 48V model. Increment of each click is 0.1V. 27 Floating charging voltage 24V model default to 27.0V 48V model default setting: 54.0V - CHANGED TO 56.4 If self-defined is selected in program 5, this program can be set up. Setting range is from 24.0V to 27.0V for 24V model, 48.0V to 58.4V for 48V model. Increment of each click is 0.1V. 29 Low DC cut-off voltage 24V model default setting: 21.0V 48V model default setting: 42.0V If self-defined is selected in program 5, this program can be set up. Setting range is from 20.0V to 24.0V for 24V model, 40.0V to 48.0V for 48V model. Increment of each click is 0.1V. Low DC cut-off voltage will be fixed to setting value no matter what percentage of load is connected. Then, low DC warning voltage is 2V higher than cut-off voltage, low DC warning return voltage is 4V higher than cut-off voltage and Cold Start Voltage is 4V higher than cut-off voltage.

I have a Mecer SOL-I-AX-3Mplus48 inverter with a set of 4 Vision 6FM100P-X AGM batteries, & 3-300watt Enersol panels. Everything appears to be working fine, and I did a load test on the batteries and they are in good shape. I inherited this 2 year old system as part of purchasing our off-the-grid home, and have a few questions regarding the settings [ones where they changed them from the defaults], so any help will be much appreciated: 1. They set the maximum charging current to 20A, even though the Vision battery specs for model 6FM100P-X say they can take 30A. 2. They chose to set their own Floating Charging Voltage at 56.4V [same as the default Bulk Charging Voltage], rather than the default 54V [note - we have hot summers in Swellendam]. 3. They set the 'voltage point back to battery mode' to a 'Battery Fully Charged' setting, rather than the default 54V. 4. And they enabled the overload bypass [default is 'disabled'], so that the unit will transfer to line mode if overload occurs in battery mode [note that the line in is only hooked up to a manually started generator that I just installed - I'm pretty sure that the previous owners had the same model hooked up, but took it with them]. 5. And something that seems strange but may be normal is that the green charging light goes to solid in the early afternoon [fully charged & as expected if there's some sun], but then stays solid even when the battery level indicator flashes all 4 bars [indicating less than 2V per cell - not sure when it starts flashing again, sometime late afternoon/early evening]. So is all the above ok, or ...? And with this setup, should I equalize the batteries once in a while, and if so, how often, at what voltage and for how long?