₦airaland Forum

olagunju2000:
Thanks Niyi and everyone. My installer saw the discussions and he is reviewing all points made. To be fair to him, I bought both the Inverter and the Charge controller myself directly from China before meeting him. He had his concerns with the cc right from time but since it was already purchased, nothing could be done. He plans to bring in different controllers to check and validate what could be wrong.

I will provide update once he is done. Thanks

Good man! I'm loving your installer already

olagunju2000:
Good day house. Please i need your help to help review my setup as I am getting not up 60% of my installation capacity

I have the following

1) 15 pcs 300W mono solar panel (3 in series and 5 parallel)
2) Panel Spec:- VOC = 44.3, Isc = 8.93A, Vmp = 36V, Imp = 8.33A.
3) Based on the connection, Total V= 132V and I= 44.65A(Voc and Isc used in the computation).
4) I have a Master Charge Controller: Max 150V and 80A (48V system)
5) Battery setup: 24pcs of 2V 600A batteries connected in series to produce 48V.
6) The setup was installed 2 months ago.
7) The highest generation seen has been 6.1Kw/day on a sunny day.
I leave at Ajah area of Lagos
9) My Depth of discharge has been around 65% until last week when I was advised to use more to see if it will boost the production. I increase DOD to 45 - 50%
10) in Real time, the maximum that I have seen is 2400W.
11) Installation was carried out by a professional.
12) I check for loses, I am only losing average of 100W (comparing power from solar output measured under the solar shed and Controller output)

QUESTIONS:
1) my total installation capacity is 4500W (solar panel), out of which I am getting max of 2400W. Is this normal
2) Is there anything wrong with my installation.
3) The power generated has not been sufficient to charge my batteries. Is there a way to improve this

Please help

Everyone has said their piece. All pretty informative. While my 3kW array has given up to 16kW/day on a number of occassions, I typically get between 5kW and 8.2kW these days with occasional peak spurts exceeding nameplate rating. I have premium grade panels, batteries, CC (with Wizbang Jr. shunt) , inverter and cabling. So we ask, what has gone wrong? Nothing!

I significantly cut back on opportunistic loads. Your batteries have a limit they can take! Your daily charge represent prior consumption + a little extra (consumption including those of the CC, inverter and transmission/conversion losses). You really can't force it and when you do, you ruin your bank by boiling it to death. The whole idea in massively oversized PV arrays is in being able to run opportunistic loads during the day as well as having a lot of reserve for cloudy days.

I rarely exceed 1,200W steady production these days. Toggle a few switches and it jumps to 1,900. Considering the heat, dust (haze) and 77% NOC yield, everything is intact. In fact, I'm more than impressed. (Makavele, Pranil and Bigrovar seem satisfied too).

Abunafiu and I, living in close proximity and having similar setups, have often compared data and they match. CCs at times report slightly different values but when in doubt, whip out your trusty (translated as quality) digital readout equipment and verify the data. I hope you're aware that panel performance degrades gradually with the greatest drop occuring within the first year (seen up to 8% for JoySolar panels, 2-3% for good/premium brands).

Lots of other variables to consider. We can all allude to different causes and ask for all kinds of data but a site inspection would be ideal. The very least (as Pranil and NiyiOmoIyunade suggested) is checking both the individual panels and the conections between them. Your professional didn't do a professional job; cable connections/termination is a big issue in elctronics (cost considerations?).

On the choice of charge controller, I'm with Abunafiu on that one - Midnite Classic all the way!

My two kobo.

pranil:
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

Was gonna make a post on this seemingly tedious issue but seeing you've put it to rest, all is well. For those in doubt, install a shunt with a dispaly/readout and your doubts would be put to rest.

makavele:
Cos those are factory-based under STC which don't apply to real life . . .
Take for example, a battery spec sheet might tell you to charge your battery to 14.1V for optimum performance
And you might be living where you do not have enough sun-hours to float your battery.
What do you do? Increase bulk charge to say, 14.6 and let it smoke . . .
** and for those who might want to argue, it's called "max smoke" in the solar world & perfectly safe***
By the time the sun goes down; you would be closer to 100% SOC
If you seem to be smoking too much, reduce to 14.4 and try again . .
no battery spec sheet will tell you this.
so forget what the spec sheets say, they are theoritical and meant as guides
throw it away, and face real conditions applicable to you and you only.

Use the specs in the sheets as guidelines. Adopt them when and where possible. Get a CC with temperature compensation (most do that now) and choose a mid-point charge voltage for smaller batteries (golf cart types) or the upper limit for tall batteries (L16 and similar). Be ready to spend on distilled water.

Or use the lower setpoint and hawk over SG drifts for about 3 months, singling out and charging weaker ones, all the while monitoring cabling and corrosion. The you can go to bed. The choice is yours.

If you're using SMF/AGM, get it right the first time and pray all goes well. Same for lithium

NiyiOmoIyunade:
Yes you can have a 48v inverter charging four batteries in series and still clamp on a 12v charger to each battery without issues so long as you do not mixup polarity. The Souer's absorb setpoint is 14.8volts so I just reduce the inverter setpoint to say 14.1 or 14.4volts during the treatment period so that the Souer does most of the charging and topping off.

So that is how I do it! I am sure by now its obvious if you go through my posts that I have pretty strange ideas about how batteries behave and should be maintained. These are the conclusions I reached based on careful study and hands on experience with various battery banks.

My kind of guy! The very reason I recently devolved 2 banks from 48V to 24V recently, including the one I use at home. Well, I use 250W x 12 PV panels so strings of 2, 3 or 4 are possible. Against routine principles, I upped my PV strings from 3 in series to 4 in series (logic says devolving from 48V to 24V banks should allow reducing strings from 3 to 2). Why did I do that? I'll post motivation, observation, inference and conclusion later. Right now, I can tell you my CC wakes earlier and sleeps only as the sun is going down. Of course it runs hotter as the fan keeps buzzing. Will solve that soon.

DMerciful:
For my EPsolar, itracer 60A, i use 2 breakers. One breaker which is a double pole breaker of 40A is btw the PV and CC lines. The other breaker of 80A double pole is btw the CC and battery. Here i only protect the positive terminal with one pole while the remaining free pole is use to break the PV input positive. This way, anythime the CC-battery breaker trips, there is no PV input to the CC

I do that too. My latest installation having that workaround failed, only to discover one of the poles wasn't making contact in the first place, forcing me into all kinds of troubleshooting. Frank replaced the bad breaker free of charge. That was 3 months ago. He does have his moments,

NiyiOmoIyunade:
This then is the million dollar question - are the successful battery recoveries we are able to perform due to isolating the batteries and giving them a full charge and thereby allowing the sulfur on the plates to go back into the electrolyte solution or are they due to the workings of the desulfators we attach? If desulfators indeed work, to what degree 10%, 50%, 100%?

Where there are other issues like you mentioned below, we obviously get no joy either with attempting a full charge or with desulfation
....

With regards to a dead or dying battery, desulphators help but aren't really reliable. The true benefit of desulphators (thus the alternate term of battery life extenders) is in attaching them to new batteries ab initio. If all else works as planned and the batteries are fairly well maintained, they do work wonders. I use car batteries for about 2 -3 years (run-of -the-mill types) and up to 5 years (OEM batteries). My current run-of-the-mill type has lasted four years without showing significant capacity degradation. I installed a battery optimizer right from the start. The other cars in the house are showing the same trend. Same battery for them all (GT).

kiekie1:
These are different points but a nice example .. In your analysis , your 40a DC breaker installed in your american inverter serves as an " overload control breaker" but it dosnt affect anything whilst it trips! Yes , but does it automatically "reset" to recharge your batteries when grid supply is available ? Does it restart after trip when it senses charge voltage from mppt / solar source ? Its a manual approach I must say... DOD settings are mostly automated in most systems and it resets itself . .

Note : Saipro, the 1.5kva inverter you have has a low battery cut off (21-21.5v) instead of 20v as you see on most Chinese inverters .. Take time to observe as its considerably okay alongside it's high surge capability & self low idle power consumption which is excellent !!!

You have insider info thus know the inverter in question, plus its ruggedness and ability to recover from hard and soft breaks. I view breaking the DC side under load the same as I would view switching off the inverter under load (Pranil's parallel LVD relay) though his resets itself and is easier to maintain (no need to manually reset the breaker).

Yes, mine has an LVD (programmable) as well OVD and lots of other features (which I'm willing to bet kiekie1 hasn't explored like I have, as I've found a way to "talk" to the hardware via an interface) but my breaker is purely to avoid overload abuse and not really an LVD issue thus I did not address the original issue whereas Pranil did.

NiyiOmoIyunade:
All lead acid batteries benefit from desulfation because inherent to their design, they will always suffer from positive grid/plate corrosion and sulfation during the discharge and recharge process - in fact the very act of recharging a depleted lead acid battey implies desulfation.

......

You can also buy a battery desulfator e.g PowerPulse or BLS (Battery Life Saver) to assist in keeping your batteries healthy. I warrant to you though that in 8 years of using these desulfator devices I AM STILL UNDECIDED if they actually work!!! Sometimes they seem to perform a miracle and sometimes they appear useless - I know though that I will not buy any new ones apart from the ones I already have.

All in all, a very long reply to a very short question - I hope it is of help

Battery desulphators are like snake oil; at times, they're the best thing since manna from heaven. At other times, they seem pointless. They've worked wonders for most of my dying batteries but for some others, no benefit. I guess that could be attributed to a lot more giong wrong with batteries than mere sulphation issues (mossing, bulged/dead plates, bridges and short circuits, outright expiry, etc.)

makavele:
It is rather not healthy cutting off power abruptly. But heck, it's not a new phenomenon . . .
How many times have you experienced watching TV and NEPA just goes like that?
Everything turns off abruptly ... TV, fridge, lights, everything ..
it's not a new thing to behold; if you grew up in Nigeria

My backup home inverter with specs 24V 1.5kVA (980W) with good overload and surge handling capabilities and reasonably low idle consumption has a 40A DC breaker fitted into the the input circuitry. The breaker doesn't trip with surge loads like compressors and motors but will do so with irons and heating elements. Instant cut-off. Occurs before the inbuilt overload circuitry trip-off has a chance to activate. Happens once or twice a week when someone forgets we're on "night mode". Reset the breaker and life continues.

I don't know of any brand which currently suffers due to DC input interruption. Inverters are buit rugged like that.

JohnKester:
I am having similar experience with 7.5KVA Prag. It was running normally and the both the DC and AC fans were running intermittently as needed according to the specified temperature. However, for a while now the fans have been running simultaneously at the highest speeds. At such times, the consumption would increase dramatically up to 3 or 4KW when actual load is less than 1KW, without there being any additional loads. The load can only be eliminated when the inverter is switched off and back on. Once the fans start running, the charging from the PV also drops, I guess because of the gigantic self-consumption of the inverter!
Cheers

Try everything thus far advised on the forum. All are safe and easy to do. The three times I've had such issues were each time
(1) a 48V MustPower inverter. Your Prag has inner workings very similar and I suspect (know) is 48V
(2) a cross-talk between earth and live or earth and neutral lines in the home wiring

Three out of three times.

Ativ:
If one uses the LVD to simply disconnect loads, the inverter continues running but self-consumption of the inverter may continuously discharge the battery below safe levels.
If one uses a device such as this, https://www.victronenergy.com/battery_protect/battery-protect , the battery connection to the inverter is opened and the inverter stops work. However, I don't know how safe it is to disconnect the battery while the inverter is working.

Like Pranil stated, it is probably easier to replace with an inverter with an inbuilt adjustable LVD.

You could use MustPower inverters in energy saving mode with minimal risk of deep battery discharge

NiyiOmoIyunade:
Two separate issues bros.
.....

For the fan always on or off setting, I suspect Saipro has made good use of the Install CD bundled with his Mustpower and has found a way to make the inverter talk to his PC and thereby effect custom settings - I am waiting for him to give the house the low down if this be the case.

Nothing so fanciful bro.
Since warranties are moot, I wasted no time in cracking open my first two MustPower inverters (24V and 48V) to ensure they stop the normal 60^o - 65^oC design operating temperature range (lower temperatures generally guarantee longer lifespan). Cutting and splicing the the negative of the fan to the core negative/ground did the trick. Alas, idle consumption rose 50%. Reverted the next morning for one (as a control) and the next week for the other. Both are still alive showing no imminent sign of demise though the 48V has be sent to the store and replaced with another 24V model

earthrealm:
i have a 4kva 48v muspower inverter with a desulphator hooked to it. the fan only runs when the temp hits 64deg, and sometimes when desulphating.
yeah, it doesnt like being charged by then, probablly cause of flunctuating voltge or frequency....maybe diesel gen with more stable output wudnt hv the same effect.
8kva HT gen output isnt so clean jumps around intermittently from 212v to 235v...n that affects the inverter....what i do is to lower the charging current to about 22amps....and its fairly stable at this seting, if i get greedy and want higher amperage...the charging trips/fluctuates off n drops to 7amps, 2amps, 11amps etc..

my only grouse with it is the high internal consumption - wch peeps here say is upto 100w for the 4kva models and above

All points true once again. The charging-with-a-generator-flicker-when-on-high-amps-charging hold true when using a backend stabiliser/AVR to "smoothen things" before running power to inverter

NiyiOmoIyunade:
For the 4kw/5kw and above the big fan on the AC end/opposite the battery end of the inverter seems to be always running. I keep mine on the outside balcony so the noise doesn't really bother me.

For the 3kw and below, the fan only kicks on when the internal temperature rises to about 60 degrees C and goes off as soon as the inverter cools down a little. The fan in these units is a lot quieter.

Considering its a chinco inverter, I am undecided which I should find more reliable - the always on fan or the one that kicks on only at a particular temperature - I can say though that I have some of them in service for years now and never yet needed to change a fan and of course the load carrying ability of any of the units is outstanding - I run a 2kw microwave and 2hp AC off the 3kw unit (not simultaneously of course but I do that for the 5kw sometimes ).

Where I find them very unreliable is the charging function from the mains or generator - very finicky and prone to spoiling in a short while - I have an unverified theory that the charging function fails very quickly when using a pulser/desulfator on the battery bank the inverter is connected to - perhaps the internal components are sensitive to the transient high voltage that the electronic pulsers/desulfators put out.

All points (including the desulphator ruining the charging circuitry) are confirmed from personal testing (I have 4 of those units in operation).

For the smaller units (3kW and below), if you put the fan on an always-on mode, idle consumption increases significantly.

pranil:
I fully second that opinion For MPPT always try to go higher than battery voltage( Absorb setpoint) by at least 5-10 Volts to ensure charging in low light conditions. But also note that there is no extra advantage in going higher than required. All the charge controllers are less efficient at higher input voltage although the difference is few percentage point not so visible in small installations

Recess suspended.
The phrase in bold is crucial in small installations. Do not forget that. You could lose way more in transmission losses while trying to get the optimal PV voltage.

Dependent on nominal bank voltage. For 48V, you need up to 20V headroom for many controllers else you'd have inexplicably low harvest till the sun is way up in the sky. For 96V, at least 30V. I tried firing up a nominal 120V bank with VoC of 160V. Of course it didn't charge one bit with MPPT. Made me laugh.
Been doing a lot of toying around lately. Stuff you wouldn't read in books. I'm sure you're doing the same.

Regarding efficiency, it seems most of the loss is due to heat loss from the conversion process (CCs run hotter the higher the conversion potential difference). Necessary for long wire runs or large PV arrays. I downsized my bank voltage to 24V (rearrangement) recently to keep a straying battery in check. My Midnite Classic has been buzzing like a bee since then.

kiekie1:
Mr Obi, sorry for the mppt issue .. I was thinking you finally mailed ep solar as discussed then . I actually stopped selling E tracer for some personal reasons & felt you will enjoy I tracer like most clients do .. Once again , sorry Bro !

The manly thing to do.
Also the sensible thing to as the seller.
Your reputation remains intact.
The rest can be sorted out amicably behind the scenes (just as the initial transaction went).
I have nothing more to contribute.
Recess is on.

pranil:
I tracer is supposed to be industrial line ( more rugged) than tracer A .

I am happy that my Tracer A has not blown in last one week I have installed. I checked on it every few hours first few days. But then it is lightly loaded ( 600 Watt)

bigrovar:
PWM or MPPT was a major decision I had to make when starting my offgrid Solar journey. After much thought and research I went with an mppt because I already had a 24v solar panel while my battery system was 12v. Using a PWM meant I would be losing close to half my PV generation potential. Also the distance between my PV and controller at 18meters meant I had to reduce losses and best way to do that was to increase voltage going to cc. Most effective way to do this was use string panel in series again MPPT controller made this a no brainer. The cost of getting an MPPT allowed me save on wires and increased the economic value derived from my system over using a PWM. It all depends on system designs.

....

The voltage difference could be all the problem liquidcrystal73 is experiencing. Sorry for the repeat reply but I'm reading and replying along. Been away a while.

GeorgeD1:
personally i think the advantages of mppt cc over pwm has been severely over-hyped and some of us here
(myself inclusive) are to blame. much as mppt has its place in the scheme of things when it comes to solar charging,
but so also does pwm. my first cc was a tristar pwm 45a and it served me doggedly for over two years without issues.
my batteries were well maintained over this period and i never had any reason to complain. i only set it aside albeit
reluctantly when i wanted to upgrade my array and discovered that cc output fell far short of what my panels would be
pushing out.

....

I wouldn't quite say over-hyped. Let's just say MPPT isn't for everyone. And it definitely isn't for every installation. If your batteries and panels are closely matched in voltage and transmission distance losses won't have you buying cables thick as your wrist, by all means, PWM all the way. Especially for arrays less than 2kW (definitely for arrays less than 1kW). The pulsing helps prevent sulphation in ways you hardly read of. Asides other smaller advantages. In fact, if you have all the aforementioned factors going for you and you have space to place more panels, use the cash difference to procure more PV panels. Of course, you know why PWM won't make sense when you go over 2kW of PV panels.

liquidcrystal73:
Of course I am calm, else I would have escalated it more than this.
Well, he gave me his Engineer's contact and I have way-billed it to him.
The engineer will take a look at it and from there we'll know stage 2.
I'll keep the house updated.

Sorry for my late response. There are other options to explore before having someone tinker with it. I'm particularly sceptical of having devices which can go up in flames being tinkered with when I can't see what's being done. True to form, I take snapshots of all panels and components on their way to and from the fix-it shop. Otherwise, a replacement is what gets me sleeping with ease at night.

liquidcrystal73:
Dead controller 24 hours into test-run . . .

Please advise

[color=#FFFFFF]CC: Pranil, bigrovar, zeestone99, pranil, DMerciful, Saipro, Kiekie1[/color]

There's something which might be worth the try. Let's offer some free advice from personal experience: I had a similar problem once. It was the unit I gave my dad. No amount of troubleshooting would make it work. No error asides that a seemingly bad controller. I remembered MPPT usually requires varying headroom to work. The kicker? The CC had been working perfectly for about 6 months. Anyway, I increased the string size thus VoC, from 38V to 76V (for a 24V nominal bank). And that did it! Why? Heat and dust usually lower VoC in harmattan. And MPP is significantly lower than VoC. The incoming voltage difference just wasn't enough to drive the MPPT of the CC. For fun, a few months later when the rains began, I reverted the connection and the CC kept working (VoC was higher).

Summary: if your CC allows for up to 100V VoC, I recommend running your panels in strings of two. Let's see if it makes a difference. But save that for a last resort fix. For now, trouble your warranty guys. If possible, let them do the workarounds with you. They should come with their own fix-it crew to prove whatever they need to.

Reprobate:
the Nigerian culture of treating warranty issues like a big nuisance/inconvenience is quite annoying.
hhope kiekie mans up and rises up to the challaenge - though I doubt, Nigerian business and warranty issues na very long thing.
only a&e dunamis has ever wowed me on warranty issues, even prag ,the mother company is no way close

epSolar changed my iTracer IT6415ND when I promised to ensure their products become unpopular on the market. Neither middleman nor importer were able to help when my first unit went bad. Decided to liaise directly with the parent company and make direct calls to the sales manager and tech support manager. A friend was in China so a replacement was sent through him.

Bought numerous units thereafter. The closest I've had to a problem after the initial one was one with a fading display unit. Proved to be a pretty reliable brand (does marginally over-report harvest and is slower to scan the array than premium brands). Would I buy another unit? Oh, I recently just got another for a friend!

Will anyone in this country honour the warranty on the label? Most definitely not. Why not? We don't hold them accountable. In my case, it became easier to deal with officials halfway across the world than people in Lagos.

idsolar:
Harmattan is here my people. I hv washed my panels twice this oct especially if u face/near untared road. Chai d sun power must be harvested by force by fire

Make mine thrice. Poor road maintenance has turned the road in front of my house to a dust-storm source. Amazingly, I had overcast skies today. Thought cloudy skies were behind us.

pranil:
No amount of oversizing should fry a MPPT CC unless you exceed the VoC. The CC limits the output current to its max rating. Although it is not a good idea to run CC at max current rating as the ratings are usually 40 /45 DEG ambient. and in Nigeria, we can exceed that in closed spaces

The morningstar is notorious for frying on battery breaker trip as it's Transient surge rating is very low. The correct way to restore the system in such a situation is to trip the PV breaker - Allow the CC to cool down and dissipate the residual charge ( usually 5-10 min) switch on battery breaker wait for a minute and then PV breakers one at a time
It is also a good idea to set the battery voltage to fixed value instead of autodetecting especially for 24 and 48 V systems as the CC can be set to a wrong value if you switch on battery and PV in rapid succession


reference -- Quote "
https://www.morningstarcorp.com/advantages-morningstars-dc-coupling-vs-ac-coupling-whitepaper/

You can size Morningstar’s MPPT controllers well above the Maximum Nominal Solar PV Input rating without damaging the controller and without the charging current exceeding the maximum output current rating. The controller can limit output current and will run at 100% of rated current output and not higher. The controller was designed with this power-shaving capability and when oversized it does not void the warranty.” – Tech Article – “Morningstar’s TrakStar™ MPPT Technology & Maximum Input Power”

Trust Pranil for his fact-finding missions. As always, you dig deep for relevant info and share unabashedly. Personally, I love you.

NiyiOmoIyunade:
Oga Pranil, verily, verily, I say unto you, all Controllers are not created equal - you can safely oversize the Morningstar multiple times over the rated PV wattage - although anything over 200% overrating, I would struggle to see the benefit and call it inefficient design.

For the EP Solar E-Tracer series, the manual states the Maximum PV Array Size = LBatt * VmP where LBatt is the maximum battery charging current and VmP is the PV maximum power point voltage. For the 60a EP Solar eTracer used in a 48v nominal battery setup with the common MPPT 3 x 3 config (3 pieces 24v nominal panels in series), that would yield LBatt 60amps * VmP 115volts = 6,900w as the maximum PV array to use (I think the manual specs 6,300w sef) - because there is some play around what the VmP may be for different panels, to be safe I would stop around 6,000W PV array size .

I have no knowledge whatsoever of Midnite because I don't like it and have never used it - a pet beef you might say I will let the users and pros tell us what the maximum safe PV over size is if any.

Between, how do you paste pictures so that they stay in the body of the text? I have tried the [img] [/img] tags but only succeeded once - I want to paste an excerpt from the EP Solar manual just like you did.

Very true.
Try substantial oversizing with epSolar and one would soon be shopping for a new CC.

NiyiOmoIyunade:
As the battery DC breaker dey trip na im I dey hear gboa!!!

It was virtually instantaneous - my batteries and CC are placed on the balcony and I happened to be on the balcony with two friends when it happened.

Quickly switched off the solar input breaker but every attempt to switch on the breaker between battery and CC to restart the CC na that electronic crackle/sizzle with some fire coming out of the CC na im we dey see.

Both the EP Solar and Morninngstar manual recommend to not disconnect the CC from battery while power from the PV array is coming in - since the CC cannot be powered off solar input there will be no way to invoke the electronic protections of the CC.

........

A Midnite Classic I supervise survived a similar experience. Kept working. Only noticed the problem because the PV voltage was unusually high and the output was zero, as if it were on standby. Lucky thing

bigrovar:
One of the things I learned while cutting my teeth as a sysadmin is the kiss principle. Keep It Simple Stupid. Same thing applies to offgrid solar. What you are proposing is very complicated and frankly is more hassle with a negative net benefit overall. The problem with low wattage device is they are also low voltage, which means even if a 12v leave the battery before it gets to the led bulb its has lost some voltages to resistance so only about 10 or 11v gets to the led. add that to the issues of fusing and breakers and how much of a mess your connection would be. Then there is the issue of using dc to dc converters which will still lead to conversion loss u were running from...

Inverters are not has bad as u are making, there are units which are 95% efficient and would serve just fine. when u compare the amount of money spent and watts lost to resistance. the former is a better option.

I run my DC security lights on auto. Without any further wiring or installation of timer switches, my security lights all come on and go off when due, year round. To forestall voltage drop, they're 24V floodlights (some are even PIR activated, to save power). Hybrids have their place.

pranil:
Skin effect is prominent in AC systems, not DC systems. In Ac systems For preventing electronic interference, however, stranded wire holds a disadvantage because the air channels between strands magnify the skin effect caused by magnetic fields on the surface of the wire.


If a Wire can be crimped by the hydraulic press than both stranded and non-stranded work the same. But for direct connection to terminal stranded are preferred due to higher contact area

Seems my memory isn't all that. Also glad I could get you to contribute. Thanks

earthrealm:
so any idea why small strand cables are prefferred to the thicker less strands type as shown in the picture below. dont really understand the explanation in the pic

...

I find it interesting that no one would volunteer the information. The issue of flexibility and crimping problems are real but the real reason is something quite different. Google up "skin effect", if my memory serves right.

Obimind1:
Its been over a month now, I lost my batteries and my charge controller(60ah mppt) all at the same time under 8months of usage. It was a tough time for me though, but the truth was that I had no one to run to. I managed to get a set of new batteries which will clock one month on the 19th of this month. I also had to fall back to my 30ah and 20ah pwm charge controller which I dumped sometime ago. Now this are my findings: I noticed that my pwm seem to have an effective cut off strength compared to my mppt cc. My pwm does not exceed 28.2v at peak Sun periods and even when I'm charging my batteries with national grid power(Phcn), but when I was using my mppt I noticed that at peak periods my cc voltage rises up to 30v and every 28 day of the month it shows that its equalizing at this point my battery voltage rises to 32v during peak Sun hours. To cut the long story short I lost my batteries and my precious 60ah mppt cc under eight months. My charge controller started showing (battery OVD). Now I'm starting all over again. I must say I learnt my lessons the hard way. Had I known I would have maintained my pwm which I was using conveniently for over a year b4 going mppt. If I am to go the mppt way again, I have to do a lot of research to know what capacity of mppt cc will be efficient for my 24v set up.

A good reason first-timers are advised to use starter batteries. The learning curve can be steep. And quite expensive, literally and figuratively. Thank God you didn't have a fire nor any of the other possible hazards.

oneshowguy:
Kung Long Batteries Industrial Co., Ltd. is a publicly traded expert manufacturer of lead acid batteries. It owns and operates two manufacturing facilities in Taiwan and one in Viet Nam. It manufactures more than 200 different types of batteries, including batteries for electric vehicles, uninterrupted power supply systems, alternative energy systems, solar energy systems, mobile energy, motorcycle and automotive uses. More information concerning Kung Long Batteries is available on its website at http://www.kunglong.com/

Can I have your local contact details?

GSM: zero-eight-zero-39612147
WhatsApp: zero-eight-zero-23902305

JUO:
if you do, they will use 24v/200ah to power 600w and tell you the batteries didn't last upto a year

Well, that's the downside ... but, I presume we're all reasonable adults ....