bigrovar:


The above is why I love flooded batteries. The ability to send equalising voltage cross all the batteries in the bank forcing all the cells to get higher voltage charge until you ensure (with the help of an hydrometer) that their voltage has been brought to an equilibrium, the ability to do this once a month means battery will never be allowed to be stuck in voltage imbalance for a long time. If you use a Valve regulated battery than your best bet is a battery balancer.

And it is better to have batteries in series connections than parallel. Parallel connection are generally less efficient, more expensive to setup and are more prone to imbalance, even with the best battery to charge/load connection the different internal resistance of batteries are more pronounced with parallel than with series. With series connection you are dealing mostly with voltage imbalance, which can be dealt easily with battery balancer, with parallel imbalance is more current.. some batteries would do more of the work and get more of the charge (thanks to internal resistance) you can try to fix this using battery connection but it only mitigate the problem.

mank1234:

What I posted has been proven scientifically and not guess work. Recheck your physics or electrical theories. The net current is independent of the charge rate so long as there's a difference in current drawn and current put in. So no need to mention C10 or C20.

In retrospect, your assumptions is more of guess work.

DUNKA:
so ssd Please out the person so that other dealers do not fall into the same trap

JUO:
Other sellers be wise

makavele:


Lol, i dey observe all ooo.
That Subomi guy ehn, i no really understand am ... even people don offer to help
him dey reject help ... na so I waka ohhh

JUO:
some people are just bad from the womb. imagine selling 40a epever cc to someone, after receiving it he decided he doesn't want it again. I refunded him only him swap the cc I sent him and sent me scrap/dead cc.

makavele:


I dont work with theories sir . . . especially those that don't apply to real life . .e.g

12v 100ah battery at 50% d.o.d on 30w load cumulative = 20 hrs backup

that is theory . . not correct in practical. . even if we adjust for losses in the system multiply by .80 inverter efficiency; still theory

even if you add battery peukert effect, still theory . .

the only way to know how long it would last, do a live demonstration and use a stopwatch !

so like i said; and still stand by, get two ammeters and do the measurement . . .

I am more concerned with the current hitting the terminals !

Until then; peace !!!

bigrovar:


The above is why I love flooded batteries. The ability to send equalising voltage cross all the batteries in the bank forcing all the cells to get higher voltage charge until you ensure (with the help of an hydrometer) that their voltage has been brought to an equilibrium, the ability to do this once a month means battery will never be allowed to be stuck in voltage imbalance for a long time. If you use a Valve regulated battery than your best bet is a battery balancer.

And it is better to have batteries in series connections than parallel. Parallel connection are generally less efficient, more expensive to setup and are more prone to imbalance, even with the best battery to charge/load connection the different internal resistance of batteries are more pronounced with parallel than with series. With series connection you are dealing mostly with voltage imbalance, which can be dealt easily with battery balancer, with parallel imbalance is more current.. some batteries would do more of the work and get more of the charge (thanks to internal resistance) you can try to fix this using battery connection but it only mitigate the problem.

Barezzi:

Where i dey since!?
Bigrovar rested this matter earlier. Same scenario plays out with my bmv702 battery monitor and midnite classic cc.

bigrovar:


This assumption is wrong in theory and in practise. Electricity flows from high potential to low potential.

Scenario 1 If say your PV is producing 1000w and your load is using 1200w, 1000w goes from your CC to your load, and the reminder 200w is taken from the battery.

Scenario 2 If your battery is full and your PV can potentially produce 1000w and your load is 1000w, the load from the PV goes straight to the inverter (Your battery is completely ignored.)

Scenario 3 If your PV can potentially produce 1000w and your load is using 500w then 500w goes from PV to load and unused 500wh would become potentials.

Scenario 4 if your battery is low and your PV is producing 800w but your load is using 800w,all 800w produced by the PV goes to the load. Non is left for the battery.

Remember like I said, electricity moves from high potential to low potential.. The lowest potential in all the above scenario is the load, not the battery. The battery always has a higher potential than the load, The battery charger in this case the PV/CC has the highest potential (so long as we are using a proper charger with the right voltage)

Its just against physics for a battery to draw electricity more than the load. The above is the theory.

For the practical, I have a Victron Battery Monitor BMV 700 the BMV comes with a current shunt which is connected to negative of the battery, inverter DC input negative cable and Controller dc output negative cable. The positive cable of the BVM connects to the battery.

The BMV monitors currents going into and out of the battery from the Inverter and CC. The BMV display shows gross net input and output to the battery hence
1 if my charge controller shows it is producing 24A and my load is 10A, the victron battery monitor shows 14A going into the battery. and this is confirmed by the battery voltage.

If I turn off the 10A load, I see the BMV showing 24A going into the battery. If I turn off the CC, the BMV will show -10A being drawn from the battery.

If my load is say 24A and CC is pulling 20A, the BMV shows -4A leaving the battery.

This idea that all power from the cc first goes to the battery and the load pulls it from the battery is false and against the principle of how electricity works. when I have time over the weekend I will demonstrate the truth of this.

HeartforGod:
Hello Pranil, a question please,

With your multiple inverters, do you have a COMMON NEUTRAL output AC wiring for all the loads connected to them? or does each inverter have its separate live and neutral wiring for their loads?

NiyiOmoIyunade:
You do bring a unique perspective to equipment/cable safety using breakers.

The three pole breaker you mentioned - is it dual rated to handle both AC & DC currents? If it is please share the brand names and specs.

I only break my inverter battery connection (60/100A DC MCB, Inverter AC charging input (32A MCB), Inverter ouput (6A or 10A or 16A.... AC MCB) as typical loads dictate.

In solar applications, I break only the solar input - I stopped breaking the CC to battery connection after I lost my 60A morningstar MPPT CC to an unexpected breaker trip one fine sunny afternoon like that - as I heard the loud bang and rushed to the balcony, I saw magic smoke, fire and brimstone coming out of the CC - IMMEDIATELY I STARTED HAVING A NASTY HEADACHE AS I CONTEMPLATED THE REPLACEMENT COST OF A NEW MORNINGSTAR CC.

NiyiOmoIyunade:
I checked online and the Yohako MPPT CC appears to be rated at input VoC 96v and max current 80a - this is probably the reason why your installer used a 2 panels in series config for you.

The challenge is now that this controller is mismatched for your application as you are using a 48v nominal system. MPPT requires some 'voltage headroom' to operate properly e.g a 48v nominal system will charge batteries anywhere from 56v to 62v (allowing for desulfation voltages) - at the panel side you will need at least 90volts to give sufficient headroom for the Charge Controller to 'boost' current and realise MPPT benefits - with 24v nominal panels, you need a minimum of 3 panels in series to achieve a useable MPPT voltage range for a 48v nominal battery bank - unfortunately, you will fry the Yohako at this voltage level.

Its either you switch to a 24v inverter and keep the Yohako as is OR you set your panels as 3 in series and change to a different controller capable of at least 150vdc e.g Chinco EP Solar/Fangpusun or the venerable MorningStar or Midnite Solar, Magnum e.t.c

As it is now you have an MPPT CC but operating like or worse than a PWM because it is not suitable for your application

You still have to ensure your panels face either South or West or East (some folks on here do North but I have no idea how that works) in that order of preference, your panel mount tilt/angle is relatively flat, no shading on the panels, properly sized cables e.t.c to be sure you have captured all angles.

But clearly, it appears your issue is a poorly designed/mismatched system and you will need some tweaking to get it right.

makavele:


Your analogy is seriously flawed because unlike a container, a battery has only 1 opening . .
the same opening for inward and outward current . . .
Current must flow to load first; and be replenished by solar array (when under load)
Or no current flows to load, and current is received by solar array (when idle and charging)
so when 30A flows to load, for example, and solar pumps in 40A back . . . current flowing into the "opening" is still 40A;
(which will kill a typical 100Ah or even 200Ah battery over time) and not 10A
Best bet is to increase battery bank
You garrit ?

Gentlemen The battery terminals work like a DC busbar unless there is a real busbar. All this current exchange happens only in the terminals and only excess current ( +ve) goes INSIDE the battery for chemistry to charge the battery or if the load is higher than battery excess current is generated by chemistry and delivered to the load in addition to CC current

As long as the CC is maintaining higher voltage than battery the entire current will go to the load .


Now you can see the reason for Hybrid inverters like ipower/zinnox/gennex where the current going to the battery is limited by the inverter but Current produced by the CC can be directly consumed by the load as the busbar is formed inside the inverter.
At one time i was running 400 AH bank ( max 40 amp charge setting) with 5 KW panels without any issues. Any excess load was automatically supplied by PV power

makavele:


I do not like guesswork.
Please place an ammeter between charge controller and battery bank;
and let us know what you get,
Then place between battery bank and inverter and let us know what you get too . .
before you do this, please ensure the CC is supplying more than the c10 or c20 current
thanks

NiyiOmoIyunade:
Yes this is correct Boss. But you only have access to SG readings with flooded batteries and even then you go tire to dey check SG on a regular basis - all the hand flushing and equipment washing to rinse off the corrosive acid can become annoying

Again SG and voltage measurements are indicators that your state of charge is within a particular range. They cannot tell you the exact state of each cell e.g on my US battery L16 flooded bank I get temperature adjusted SG readings between 1.275 and 1.295 across all cells when my batteries are fully charged. Yet if I run say my 2hp AC for like 8 hours its the battery with one cell at 1.295 that collapses first

With all the charge in this world (my array can generate a max 75amps into a 360AH bank if I don't cap the output) I have not gotten the SGs to converge. In a moment of madness I even started siphoning electrolyte from the 1.295 cell into the weaker ones yet no joy

So I settled for simply clapping an individual charger on each battery on a regular basis and keeping the water topped up.

Flooded is good but as you would have seen from people's experiences on here with their Trojans and my own US Battery L16s, after a while things start to go south and they need ever more and more babysitting to keep them healthy.

As it stands now, I have given up on lead acid, our salvation now seems to be Lithium with the promise of negligible or zero sulfation/loss of capacity even at 80% depth of discharge.

pranil:


Or just use Victron Battery balancer - https://www.victronenergy.com/batteries/battery-balancer

Dam5reey:
BMV is a device on its own that uses shunts and also sort of battery management as well as it's calculations...

I'm sure makavele is not using shunts.. he connect his cc and battery directly... so his practicals is correct as well...

pranil:


72 Cell panels Typically 250 watt and above are higher Vmpp appox 34 to 37 V so it is enough to use two panels in series for 48 V battery . For sixty cell panels, it is better to use three panels for headroom

Infact a 72 V cell panel 3 in series you have nominal loss of 1-5 % of rated power due to conversion from higher volatge to lower volatge

NiyiOmoIyunade:
This is an interesting argument - much akin to three men feeling an elephant by touch and one who felt the sides decides the elephant is much like a wall, the one who felt the leg decides the elephant is like a tree while the guy who felt the tail decides the elephant is much like a rope.

I think it's all a matter of perspective but I will wait to see how things pan out.

pranil:


In my case the zinnox are wired in parallel with common neutral and phase - but they require a seprate parallel board plus communication cable between two inverters and current sharing cable

If the manufacturer has not clearly indicated if the inverters can paralleledled then NEVER parallel them even only neutral [font=Lucida Sans Unicode][/font]


In case of grid failure the neutrals will be floating and can cause circulating currents between inverters and all kinds of strange behaviours

makavele:


. . . and the one who felt the tusk decided the elephant was much like a spear;
while the one who felt the ears said the elephant was more like a fan

NiyiOmoIyunade:
Lolz!

Based on what you have explained in your earlier posts at least I know you have a clear picture of what the whole elephant looks like

NiyiOmoIyunade:
Valid point about floating neutrals.

If we break only the live wire there is a very good chance that the neutral could become energized when the breaker trips.

Noted for my future designs.

makavele:


People that know me know I am more of a practical man ..
i will post a video tomorrow concerning this;
at least not to argue but for knowledge purposes

pranil:


The DC system in the video is ipower charge controller/inverter also contributing 250 watts for the load along with Victron charge controller

kiekie1:


Pls hope am not the only one interested in the said video clip?

bigrovar:


This assumption is wrong in theory and in practise. Electricity flows from high potential to low potential.

Scenario 1 If say your PV is producing 1000w and your load is using 1200w, 1000w goes from your CC to your load, and the reminder 200w is taken from the battery.

Scenario 2 If your battery is full and your PV can potentially produce 1000w and your load is 1000w, the load from the PV goes straight to the inverter (Your battery is completely ignored.)

Scenario 3 If your PV can potentially produce 1000w and your load is using 500w then 500w goes from PV to load and unused 500wh would become potentials.

Scenario 4 if your battery is low and your PV is producing 800w but your load is using 800w,all 800w produced by the PV goes to the load. Non is left for the battery.

Remember like I said, electricity moves from high potential to low potential.. The lowest potential in all the above scenario is the load, not the battery. The battery always has a higher potential than the load, The battery charger in this case the PV/CC has the highest potential (so long as we are using a proper charger with the right voltage)

Its just against physics for a battery to draw electricity more than the load. The above is the theory.

For the practical, I have a Victron Battery Monitor BMV 700 the BMV comes with a current shunt which is connected to negative of the battery, inverter DC input negative cable and Controller dc output negative cable. The positive cable of the BVM connects to the battery.

The BMV monitors currents going into and out of the battery from the Inverter and CC. The BMV display shows gross net input and output to the battery hence
1 if my charge controller shows it is producing 24A and my load is 10A, the victron battery monitor shows 14A going into the battery. and this is confirmed by the battery voltage.

If I turn off the 10A load, I see the BMV showing 24A going into the battery. If I turn off the CC, the BMV will show -10A being drawn from the battery.

If my load is say 24A and CC is pulling 20A, the BMV shows -4A leaving the battery.

This idea that all power from the cc first goes to the battery and the load pulls it from the battery is false and against the principle of how electricity works. when I have time over the weekend I will demonstrate the truth of this.

makavele:


it is always a safer option to have dedicated lines in electricity ...
the only draw-back is cost of wiring . .

zeestone99 take note !! you & your unrelenting love for common wiring

makavele:


I dont work with theories sir . . . especially those that don't apply to real life . .e.g

12v 100ah battery at 50% d.o.d on 30w load cumulative = 20 hrs backup

that is theory . . not correct in practical. . even if we adjust for losses in the system multiply by .80 inverter efficiency; still theory

even if you add battery peukert effect, still theory . .

the only way to know how long it would last, do a live demonstration and use a stopwatch !

so like i said; and still stand by, get two ammeters and do the measurement . . .

I am more concerned with the current hitting the terminals !

Until then; peace !!!

mank1234:
This is derailing from the issue in contention, which I believe bigrovar has setttled.

Even on this one. The theories as stated by the manufacturers would likely hold barring marketing gimmicks, as long as you hold the variables (temperature, pressure, load etc) precisely as stated by the the manufacturers. Manufacturer cannot state a test result at 25^oC for instance and you do yours at 30^oC and expect to get same result.