Learner set up

[Whats_per_question]

@NZ12VOLT ; that breaker on your solar cable looks like a C20 AC breaker. There are DC breakers available, and given its a caravan I'd recommend using a proper DC breaker as they have arc catchers, and will break correctly. AC breakers are not meant for this. On 12v DC for something like isolating a string of lights, an AC breaker is fine because you are using it for switching, not breaking. For your controller (Epever) you could be running anything up to 150v DC on that solar cable, so it pays to have a DC breaker.

 

[Whats_per_question]

Well this what I was doinView attachment 183862,View attachment 183884,forgot me dimmer for lights.
Shorter cables ,my join was sweet,just trimmed insulation down to fit before crimping
Turned on for test and working well,it was working well before to lol,but much more semi organized, had wires all over the place ?.
Yip its basic but doin more than I expected it would for what I need ?

Great to see you have swapped out the cable you had for the battery->inverter for a thicker cable. I think you have 16mm cable now, but if you find some 35mm cables that would give you even less voltage drop between battery and inverter with the kinds of currents you might be pulling.

 

[NZ12VOLT]

Hi. Those 5m cables you got from TradeMe - the cables in the advert are wired correctly - the positive on the panel is the male connector, so the positive on your cables from panel to controller will be the female connector. If you aren't sure, just connect it all up and put your multi-meter on the wires before going live. So it looks like the cables delivered were color-inverter?

ah thanks yeh it just didn't look right having a red negative color wire,to me negative is black colour

@NZ12VOLT ; that breaker on your solar cable looks like a C20 AC breaker. There are DC breakers available, and given its a caravan I'd recommend using a proper DC breaker as they have arc catchers, and will break correctly. AC breakers are not meant for this. On 12v DC for something like isolating a string of lights, an AC breaker is fine because you are using it for switching, not breaking. For your controller (Epever) you could be running anything up to 150v DC on that solar cable, so it pays to have a DC breaker.

Thanks again ,good info,I do have this comingbut slow due to couriers, Not even sure if this correct breaker off on switch but still looking to improve my little project ,its been running last week with no issues, just my inverter is a baby but work well running TV, phone charger,cloudy days the system loves, full sun the poor inverter sits on 14.4 almost its HV cut off because the PV input to my battery I cant use the power its making so shut it down as to not cook my only inverter,this was another thought I had with the BT50 was to go into USER setting and lower the 16v over voltage cut off and couple other settings like in a clip I watch,, still looking at those inverters no more cheap ones lol.,
I did have a BT-50 ordered which arrived today so got that hooked up so I Can learn and get a idea of what's goin on ,read alot,watched few vids on YouTube to understand the parameter side of it,,the mppt works the same so mayby a helpful gimmick or unnecessary for small system
.And still waiting for some 4awg wire to arrive
Totally agree on the tube type breaker ,rookie purchase lol,looked good but didn't investigate them at all,I just presumed it will do but def not,
Yip the inverter wires at moment are 5awg ,the 4awg not arrive yet so 5 it was ,I have been looking at battery isolation switches as well and probably will get one when all in open and deliverys are normal,,and I have a feeling this battery breaker is not the right thing ,I should have ask again but i will get another if no good
Awsome and thank you and safe merry xmas to all,,,,,and dont ask me why this post is all somehow paragraphed like it is,,it just does it

 

[NZ12VOLT]

Ok my curiousity is asking about the charging limit voltage and this thought is to see if I drop the charging limit will that reduce the voltage going to the inverter.? I think its bit much for it to sit high at 14+volts on sunny days with 31volts from the PV since my appliances dont use much power ,hey power is cool dont get me wrong but this inverter holds a nice 12.9 to 13volts with 42" TV going without out the fan even starting but over that and fans a pain to listen to,sometimes constant but mostly revving Highly very intermittently which tells me it's starting to work hard cause of the high PV input and I can't use enough power to drop the voltage at the inverter,,sure the MPPT stops it overcharging, but on bright days, that's why cloudy days seem just right,,confused yet lol,,picture is default MT50 settings for sealed battery at 15volt....USER can go between 9 and 17volts,,me want to try 14volts for charging limit voltage setting ,might have to adjust couple more but MPPT almost identical presets
Will this carm things down for the inverter, the videos I watch seem safe but they clever buggers,I know I need a better one ,been looking,not cheap ,

Still lot to learn dispite the amount of reading and do have slight hesitation of adjusting parameters till i know if it's safe to do so,manual never explains things properly and YouTube it's like monkey see monkey do type situation ha
Be interesting to see what the panel is producing on the BT50 display, is slightly more informative to see than going through modes with just the mppt controller which keeps changing by itself
Thanks

 

[Rednecktek]

You'll be OK to drop your voltage limit to make your inverter happy. As for the extra power, your equipment is having a conversation along the lines of:

SCC - "Hey guys, I got power to spare, who wants some?"

Battery - "I could use some, pass me them amps."

Inverter - "I gotta feed this guys TV, send me some of those watts too!"

Panels - "I think I can, I THINK I can."

Battery - "Ok, I'm full, no more for me."

Inverter - "He fired up the microwave! HELP!!"

Battery - "Here's some amps dude, I'll get them back from the panels tomorrow."

And so on, and so on. Your panels will only produce power when the loads ASK the controller for power. If the battery is full and the sun is shining, the panels will feed the liads. If the battery is empty it gets dibs and the controller tries to max out as much charge as it can get from the sun.

 

[12VoltInstalls]

thanks yeh it just didn't look right having a red negative color wire,to me negative is black colour

Do not be rigid or assumptive regarding wire colors! Depending on AC, DC, phases, device, and standardized ‘codes’ the wiring inside devices is not always what you think. With DC for example, neg(-) could be white, yellow, black, green, blk/org, etc.; and pos(+) could be red, yellow, black or other things that might not make sense - to you.
Even AC inside certain equipment might not be what you’d expect.

Just saying use your meter, be safe, don’t die.

 

[NZ12VOLT]

You'll be OK to drop your voltage limit to make your inverter happy. As for the extra power, your equipment is having a conversation along the lines of:

SCC - "Hey guys, I got power to spare, who wants some?"

Battery - "I could use some, pass me them amps."

Inverter - "I gotta feed this guys TV, send me some of those watts too!"

Panels - "I think I can, I THINK I can."

Battery - "Ok, I'm full, no more for me."

Inverter - "He fired up the microwave! HELP!!"

Battery - "Here's some amps dude, I'll get them back from the panels tomorrow."

And so on, and so on. Your panels will only produce power when the loads ASK the controller for power. If the battery is full and the sun is shining, the panels will feed the liads. If the battery is empty it gets dibs and the controller tries to max out as much charge as it can get from the sun.

Premo what a reply ,I can imagine the system talking like that too lol ? Dont have microwave,or fridge but understand the explanation, good stuff,
From my understanding of the parameters from watching some clips I just go into USER and program the SEALED battery default settings but lower the charge limit voltage which seems at the moment only default setting that I need to change but will check again to make sure.
battery been good apart from wet days,input bit lower ,ì just use main power on those days so battery always above 12v.
Thanks again,I will update the verdict,
Picture from now at 10.04am and it's dark and wet with TV on holding steady dispite low input ,inverter on 12.2,and silent,,from now the voltage will increase during the day ,,coffee time and then I'm in there before the sun re appears

Just a couple pics showing TV on only and current, amp usage ,1.35pm still low wet cloud

Under the USER for doing changes they give you logics to follow I presume so things successfully save
A= Over voltage Disconnect first >Charge Limit Voltage, and so on but when change to 14v from 15v it says para error and changes back to 15v ,trying to follow the order it's in but stuck there,
Default settings in manual for both MT50 and MPPT are identical but mismatch or operate error .been lits of thinking goin on lol
Bit of light appeared

 

[NZ12VOLT]

Do not be rigid or assumptive regarding wire colors! Depending on AC, DC, phases, device, and standardized ‘codes’ the wiring inside devices is not always what you think. With DC for example, neg(-) could be white, yellow, black, green, blk/org, etc.; and pos(+) could be red, yellow, black or other things that might not make sense - to you.
Even AC inside certain equipment might not be what you’d expect.

Just saying use your meter, be safe, don’t die.

Yip I'm with you ,Yip use multimeter all the time ?

 

[NZ12VOLT]

Another dark wet day but managed to lower charge limit to 14.6 and finally it saved it ,
Sure didn't work how manual shows,now waiting for fine day for test ?‍?

 

[NZ12VOLT]

Update to that is that it dont work,full sun the inverter still shut down from HV alert while in use,
Dispite the MT50 settings ,that's all irrelevant to the inverter since its powered by battery and not through MPPT load,,,was good idea if the inverter was wired into the controller but dont work like that,
Solution = new inverter. Looked at 100s now and semi good ones ain't cheap,prices are just outrageous at the moment

 

[Whats_per_question]

That looks like an Epever MT50 display unit.
With the Epever controllers, there are a bunch of rules (for example, Undervoltage reset has to be greater than the undervoltage alarm), and the Epever isn't very user friendly when it comes to telling you which rule you have broken. I find that when i'm programming the Epever charge controllers, its easiest to go *backwards* through the settings, as almost all the settings that we use (for 24v LiFePO4 batteries) differ from the defaults in a direction that means that starting at the first setting results in many un-savable settings. Going backwards results in every setting being saved first time.
Even easier, if you have it available, is using the Epever bluetooth dongle ( https://roarpower.nz/off-grid-solar-products-nz.html#ccaccessories ) to use your phone - the phone app interface is much nicer to use.
Message me if you want the good oil on settings for the Epever controllers for LiFePO4 batteries - I've done a fair bit of trial and error with overpanelled and underpanelled epever systems, but only on LiFePO4 batteries - others on this forum will have the knowledge on the best settings for lead acid and gel.

 

[Whats_per_question]

@NZ12VOLT - remind me; what is your battery chemistry?

 

[NZ12VOLT]

@NZ12VOLT - remind me; what is your battery chemistry?

Simple car battery Rubbish but it's what I could afford ,deep cycle battery 400+ for cheap one
Yep good info above I think that's how I manage to save settings in MT50 but lot of searching to find that out,,this cheap battery was 190 ,piss me off cause recent took a proper one in with some scrap metal, now I have a caravan its needed ,I hate that lol
Yeh interesting the wifi module part for app,I did see that somewhere, lot more user friendly
Anyway at least I learnt how things work in all that but it's just the inverter I need ,most inverters HV cut off is 15 to 15.5,,,this 600w inverter HV is 14.5v, so I'm off looking again

 

[Whats_per_question]

Simple car battery View attachment 186120Rubbish but it's what I could afford ,deep cycle battery 400+ for cheap one
Yep good info above I think that's how I manage to save settings in MT50 but lot of searching to find that out,,this cheap battery was 190 ,piss me off cause recent took a proper one in with some scrap metal, now I have a caravan its needed ,I hate that lol

Thats cool NZ12volt - lots of people use these, they just don't last too long but if we can get your settings perfect you can get a good life out of it.

The great thing about car batteries is that the scrap value is about $5nzd. A scrap battery might not start a car (100A to 300A or even more to crank a car engine) but they can carry on running for years if the loads are modest (such as LED lights, small inverters etc).

Do us all a favor; go through your MT50 and fill in this chart so we can help you with your settings.
Over Voltage Disconnect Voltage
Charging Limit Voltage
Over Voltage Reconnect Voltage
Equalize Charging Voltage
Boost Charging Voltage
Float Charging Voltage
Boost Reconnect Charging Voltage
Low Voltage Reconnect Voltage
Under Voltage Warning Reconnect Voltage
Under Voltage Warning Voltage
Low Voltage Disconnect Voltage
Discharging Limit Voltage

These are the setting names on the Epever Bluetooth App - the setting names on the MT50 might be slightly different but from memory they are in the same order. Once we can see all your settings we can help more.

One note: That scissor-action disconnector you posted a pic of (that i think you ordered) looks like just a disconnector - no circuit breaker feature. This is fine, its capable of high current, but you probably would have been better off with a proper DC breaker ; here's an example from a company not far from you - https://roarpower.nz/off-grid-solar-products-nz.html#breaker63
Let us know before you purchase anything more ... the forum members have decades of experience and can "vet" items to make sure they are appropriate for your system.

 

[NZ12VOLT]

Over voltage disconnect voltage 15.5v
Charge limit voltage 14.6
Over voltage reconnect voltage 15v
Equalize charging voltage 14.6
Float charging voltage 13.8
Boost reconnect charging voltage 13.2
Low voltage reconnect voltage 12.6
Low voltage disconnect voltage 11.1v
Under voltage warning reconnect voltage 12.2
Under voltage warning voltage 12v
Discharging limit voltage 10.6
Equalize duration 0min because only 1 battery not 2
Boost duration 10min
Some settings I found cant be changed so they remain default settings and not 100% if my inputs are correct but it worked
Would be nice to have correct set up though

Ok yeh I been looking at DC breakers too,I knew it not right,
I already got this type on line before mppt controller to shut that side off,I add a pic in a sec,

Yip had itching BUY now button on trademe but I learned from the first cheap one so looking hard now ,

 

[Whats_per_question]

Great documentation.
I'll make one post per settings so that others can disagree or comment

"Equalize duration 0 minutes, because 1 battery not 2"

Equalization is to bring each cell up to the same voltage as the others. On a flooded lead battery you boil the crap out of the cells to do this, because a high cell will just turn water to hydrogen and oxygen, and I the mean time the low cell comes up to full.
You might have been thinking of balancing, where multiple batteries are brought in to the same voltage and state of charge.
You should set eq duration to something like 30 minutes, others will know more on this topic

 

[Whats_per_question]

All the settings can be changed- its just that some are only allowed to be in a range, and often the lower or upper bounds are set by other settings. For example i think you can't change the charging voltage to 14.5 while the Equalization voltage is 14.6 - you have to change Equalization voltage first. Might be wrong for that settings, and I don't have an epever on hand to check, but that's the sort of pattern you will find

 

[Whats_per_question]

Over voltage disconnect voltage 15.5v
Charge limit voltage 14.6
Over voltage reconnect voltage 15v
Equalize charging voltage 14.6
Float charging voltage 13.8
Boost reconnect charging voltage 13.2
Low voltage reconnect voltage 12.6
Low voltage disconnect voltage 11.1v
Under voltage warning reconnect voltage 12.2
Under voltage warning voltage 12v
Discharging limit voltage 10.6
Equalize duration 0min because only 1 battery not 2
Boost duration 10min
Some settings I found cant be changed so they remain default settings and not 100% if my inputs are correct but it worked
Would be nice to have correct set up though

Ok yeh I been looking at DC breakers too,I knew it not right,
I already got this type on line before mppt controller to shut that side off,I add a pic in a sec,
View attachment 186128
Yip had itching BUY now button on trademe but I learned from the first cheap one so looking hard now ,

If you are getting over-voltage problems with your inverter, change the Equalization voltage to 14.4, then save, then change charging voltage to 14.4, save, then wait for full sun, full battery, and see if the error still exists. Repeat the process, going down by 0.1v at a time, you should be able to get rid of the overvoltage error. Sometimes epevers with full sun and full battery have a hard time keeping the charging voltage at the nominal voltage, so we drop the charging voltage to leave a little more buffer between the charging voltage and the inverters trip/alarm point.

 

[Rednecktek]

Ummm... car battery. Set it for 13.8v.

 

[Whats_per_question]

Ummm... car battery. Set it for 13.8v.

Thanks @Rednecktek - That's a good prompt to discuss battery life.
Generally, regardless of the chemistry of the battery, the lower you set your charge limit, and the higher you set your discharge limit, the longer the battery will live for.
The flip side to that is that you have paid some $ for some Ah, which lets say is nominally the capacity of a particular battery between the voltages of 14.4v (full) and 12v (flat). If you set your points to stop charging at 13.8v and stop discharging at 12.9v, you are not able to use around about 30 percent of the amp hours you paid for. So you could say you have spent 30% of your money on a part of the battery you can't use.
But ...
I would think of it this way - you have traded 30% of your battery capacity, for probably more than 30% longer life.

For a battery that absolutely must live a long time (lets say its buried or in a satellite, or similar "cost" to swap over) you don't want to be discharging to a low SOC, or charging to full SOC. You are better to have aggressive power management, such as turning off everything except "life support" when the SOC gets low. For systems i have been involved with, this means surveillance cameras go off first, then environment measuring tools (temperature, humidity), then comms last of all (keep these going so that you can turn cameras back on if you really really have to)

This also applies to charge rates and discharge rates; if you charge a 100Ah battery at 100A, ("1C" in the battery language, amps divided by amp-hours) it won't last very long. Same with charging ... a 100A BMS might be able to handle 100A of charge, but its not doing the cells much good.
The great thing about solar is that generally the charge rates are low (compared to the total Ah of the battery pack), typically (for example for @NZ12VOLT i think he has about 11 amps going into something like a 400Ah battery, or 0.02C which is very very low) but sometimes the discharge can be high (eg for a 2000w inverter, that can surge to 2400w, at 12v, = 200A! or 0.5C)

0.5C is generally considered a good standard to keep your currents below.

 

[NZ12VOLT]

Great documentation.
I'll make one post per settings so that others can disagree or comment

"Equalize duration 0 minutes, because 1 battery not 2"

Equalization is to bring each cell up to the same voltage as the others. On a flooded lead battery you boil the crap out of the cells to do this, because a high cell will just turn water to hydrogen and oxygen, and I the mean time the low cell comes up to full.
You might have been thinking of balancing, where multiple batteries are brought in to the same voltage and state of charge.
You should set eq duration to something like 30 minutes, others will know more on this topic

Ok done ,that 1 battery part came off a clip I watched so he was wrong too in explaining,

If you are getting over-voltage problems with your inverter, change the Equalization voltage to 14.4, then save, then change charging voltage to 14.4, save, then wait for full sun, full battery, and see if the error still exists. Repeat the process, going down by 0.1v at a time, you should be able to get rid of the overvoltage error. Sometimes epevers with full sun and full battery have a hard time keeping the charging voltage at the nominal voltage, so we drop the charging voltage to leave a little more buffer between the charging voltage and the inverters trip/alarm point.

I have just changed to these settings and waiting for tomorrow, looks like hot day coming for Kapity coast
Yeh the 13.8 sounds good, Do I try do that or test other settings first

 

[Rednecktek]

We could summon the expert on this...

Hey @12VoltInstalls , car battery voltages?

 

[NZ12VOLT]

Update to that is that it dont work,full sun the inverter still shut down from HV alert while in use,
Dispite the MT50 settings ,that's all irrelevant to the inverter since its powered by battery and not through MPPT load,,,was good idea if the inverter was wired into the controller but dont work like that,
Solution = new inverter. Looked at 100s now and semi good ones ain't cheap,prices are just outrageous at the moment

Update to that is my understanding was wrong on the mppt or mt50 with my comment about bein irrelevant since inverter runs of battery, well these things tell that thing what to do,blame that on a senior moment, no I wasent drinking but think I need one even though I don't drink ,to much thinking

 

[12VoltInstalls]

if the inverter was wired into the controller but dont work like tha

Never run an inverter from an SCC ‘out’ terminal.

 

[12VoltInstalls]

Hey @12VoltInstalls , car battery voltages?

Starting battery or deep cycle/marine, a half hour “boost” at 14.2 won’t hurt, 13.8 float is great. I’d manually equalize a car battery monthly so I could monitor/watch it, but probably a deep cycle I’d just let it do it automagically and make a point to check the electrolyte levels regularly.