₦airaland Forum

DMerciful:
Battery going out of sync is the biggest challenge to series batteries. I am changing the configuration of a client system to 12v bcoz of this. For me the max system voltage should be 24v..best is 12v.

You sacrifice system efficiency in the process. It all depends on how wiring is configured and how good the batteries are. for anything higher than 3kw inverters I prefer 48v. Issues of batteries going out of sync are common in parallel connection more so than even in series. The main cause of these problem is bad wiring. (Well even in the best of wiring, difference in internal resistance of batteries even those from same manufacturers means with time they will go out of sync) This why I love FLA. Equalization helps alot in addressing this issues. For FLR, a battery balancer during initial installation stage is best.

NiyiOmoIyunade:
I agree with you Sir.

That is why although I take a keen interest in any news about Lithium batteries, I am still on the fence and have yet to use/embrace it on account of the associated complexities of BMS and avoiding overcharge and keeping batteries balanced and in sync and the effects of temperature on battery performance e.t.c

With the high initial purchase costs, the price of failure or mistakes or system mismatch would be very high indeed and I cannot in good conscience use my clients to learn unless I am sure I have a full grasp of the technology and what will work.

Above all, I am yet to see any field experience locally in Nigeria to justify the ultra long 10 to 40 years of cycle life that Lithium users lay claim too - not saying it's untrue but I need hard evidence/testimonials rather than manufacturer marketing claims to be convinced.

Energy storage is at the mid way point of its transition from Lead Acid due to pressure to find a more sustainable means of generating energy. I honestly see lithium to be a stop gap technology that might soon be superseded as more research money is thrown at solving the energy storage problem. Lithium is still a rare earth material available in very few places on earth. Even if the technology stabilises I expect price would go down up to a point thanks to technology and then shoot up as the low price drive demand .. and that demand would eventually outstrip the supply of lithium. I strategy is to sit and wait and see how it all pans out. The high cost of Lithium now is what is funding many of the research into making it a stable commodity and the raise of electric cars will put more pressure into pushing down price of energy storage and lead to the creation of turnkey all in one solution. My next major upgrade will still be lead acid based probably see what the next 5 years will hold.

makavele:
You want to be frustrated by sweeps??

Pls use an ePever;

You will shed tears.

OMG.. RED TEARS. The worst is the BN series of controllers. I once timed it for 4 minute before it recognised cloud change and perform a sweep.

NiyiOmoIyunade:
I have this same argument with some stubborn clients who want to pay for a minimalist system (read small battery bank) but abuse it regularly with heavy loads - they stubbornly insist this is the only way (undersizing battery bank and other aspects of the system) that makes financial sense.

My current battery bank is sized for at least 3 days of autonomy even with overnight AC use. So far I have yet to call upon my generator in the last 6 months even on the worst of days, it would take at least 4 successive days of rains and cloudy weather to drain my battery bank completely and by day 2 of low sun and cloudy weather I would have stopped using overnight AC on account of the cool weather and thereby bought myself a few more days of battery backup.

The few clients I have who have taken my advice at the design stage have all practically forgotten how the PHCN side of their house works and have certainly forgotten completely how to put on their generators

Again most offgriders abroad keep a small backup Gen for emergency power just as Oga DMerciful said. Just last month, I bragged to one of my sceptical clients that if I had NGN3Million to spend today, I would certainly apply it towards getting a Lithium battery bank and 1000w more in PV panels vs. using it to buy a 20kva Diesel Gen.

Such is the level of confidence I have come to have in the sustainability of solar power and the offgrid life.

The down side of having that much battery capacity (relative to daily consumption load of cause) is you most have the capacity to fully charge them at the first chance (first clear weather day) this might not be as easy as you might think no thanks to battery inefficiencies. if your solar panels are not adequately sized you might end up in the battery being in constant state of being under charged which will lead to sulphation. For long life of your battery, your daily use should align the capacity of your PV to refill in one day of charge.

Fortunately, nature has a way of balancing things out, myself was affected by the bad weather but the good thing is temperature was generally cool hence less need to use energy for climate control, also the panels got much needed cleaning ... I take the last friday weather as an ominous sign of things to come. Climate is changing and we might see much worse weather come May - June - July - August.

I use a weather app called Weather radar on android and it is the most accurate at weather prediction. It did predict that Friday would get 0 hours of sunshine and 90% chance of rain. This made me to prepare by going on a lean mode on thursday. Thankfully the app is predicting 5% chance of rain and 9 hours of sunshine today and tomorrow but thursday this week is a bit tricky. You can download the app here https://play.google.com/store/apps/details?id=de.wetteronline.wetterapp&hl=en

Barezzi:
Nah brah! You can get it at even 280 Matt 7:7

show us the way

pranil:
Is there any recommended installer in Abuja for doing quality jobs

Based on my annual tradition I am adding 1 KW on the roof and would like to take the opportunity to rearrange my strings
So basically supply 1kW panels, 6 mm2 cable, aluminium rails etc. (rails including existing 10 250 Watt panels)




wbr

Anil

I know a guy who usually does the work for Zinox. He is quite capable 07035954213

DMerciful:
Congratulations. Decent system. I am impressed how you are able to achieve appreciable longevity from those batteries

Actually not that hard. Focus on system design especially ensuring consumption aligns with generation. This allows me to achieve a daily cycle of the batteries at about 38% dod. With a discharge rate of below 5Ah (C40) for over night i.e about 7 hours use and 9AH (C20) during the early evenings for about 4 -
5 hours when TV and indoor lights are on.

Heavy loads like fridge, freezer, washing machine are used during the day thus ensuring the about 60Ah coming from my panels are used up as opportunity loads allowing a safe 22A go into the battery. The relative light battery depth also allows the battery a faster time to out of bulk and into absorption where current would be regulated.

All this ensures the battery gets adequate and proper charge to float on a daily basis.

The end result of all these is, 2 years on battery still works like new.

Malevonent:
congrats on the move, nice setup you have. the roof mounts...are the prefab or locally made?..am looking for cheap mounts that will contain 6 panels, they said the prefab mounts can only take 4

mix of both. 6 panels are on prefab 2 are on locally fabricated. Actually the locally fabricated are mainly perforated angle iron bars in my opinion they do a much neater job compared to the turnkey mounts and allow for easier adjustment on the roof.

Just finally moved to my own modest house. Decided to finally take a chill pill on the race for the higher wattage and settle for efficiency on the consumption side. This allowed me to set aside some funds for putting a roof over my head all glory be to God. My 1.84kw panel is all the electricity I need for now. I will connect to the grid once am done with some finishing touches to the house.. I generate enough to provide me 24 hours electricity that meets every basic needs refrigeration, laundry, light, TV, kitchen stuff.

The house runs on LED spot lights the highest being the single 12w kitchen lights. Over night amps draw before sun rise is 75AH from a 24v 200ah battery. I had time regig my setup.. Power drill was a life saver.

makavele:
He Mentioned 1000VA and about 800VA or so; . . which would struggle like hell. I was in that shoe before. Unless the appliances have been ice-cold from PHCN the previous night, the inverter would never start any of them. Someone even mentioned a trick here; starting the freezer with a generator then switching over to inverter . . . which worked 50/50 for me

Negative, should have stopped at struggle to start. My first inverter was a 1050va (about 840w) and yes it did struggle to start the freeze but it did start it and once started the freezer ran fine. The freezer is a 175L chest mode from LG.

Freezers should generally be given some time when turned off.. (like 5 minute) before turning them back on.. this would allow the compressor to reset (you will hear a click sound when this happens) doing this reduces the start up surge.

I eventually replaced the inverter with a 1.5va (1300w) inverter and the latter started with freezer with no hassle at all. But Inverters are from sukam

NiyiOmoIyunade:
Many thanks for this Sir.

I myself have seen a similar document that made me more confused because it mentioned 13.8v boost voltage as the upper cap

Please how do you interprete the boost voltage guidance especially the upper/over voltage limit?

Is it 13.8v per 12v battery or between 13.8v to 14.2v per 12v battery?

I think the 13.8v is the absorption start point and 14.2v is when absorption ends. Some chargers use absorption end point voltage to among other things decide when a battery is well and truly done with absorption stage. Most AGM batteries set this to 14.4 however Quanta know best the composition of their battery and they know best why they set the 14.2v. If I were using their battery. I will set my absorption voltage to 14.2. The higher the voltage the less chance of sulphation (since agm can't be equalised)

mcTrinity:
2 weeks plenty.... I know of a radio station where 3# of that ipower 5kva with 5.7kw Solar on each were installed. Told the engineer that it's a bad idea to use that kind of set up for an off grid radio station.

immediately the systems were powered, one of the inverters was blown. had some liquid-like fluid coming out from the inverter.
To cut the whole story short, after the inverter was repaired and returned, the same incident repeated again. After many arguing, he bought an external CC (of course from his pocket, not from the radio station)...

I also noticed something that shocks me with this hybrid system. At any point in time, If the load capacity becomes less than the solar power, the Inverter won't charge the battery. there were times that the solar power was showing around 2.7kw but the load capacity was around 2.9kw and the charger wasn't coming on. it only comes on once the solar power excess that of the load. Can you just imagine that!!! 2.7kw and battery won't charge.!!! this was monitored for 4hrs and the inverter charger keeps coming on and off depending on whether the solar power is greater or less than the load capacity.

After everything, the engineer got another external CC (that's 2 now) while he left one Inverter to be solely hybrid and he subsequently reduced the load to less than 2kw.

It was a bitter experience for the supposedly engineer and even though I tried to advice him ab initio the installation, he didn't listen and I didn't expect him to; after all I only happened to be there for a different purpose but I decided to stay and observe. so how can a solar engineer take advice from an observer?? lolz
I really learnt from that his mistake

So, PERSONALLY for ME, hybrid system is a no go area.

Solar installers. Most of them will ruin you if not care. My advise to folks is to endeavor to RTFM and not just rely on the words of the installer.
. My institute sometimes in 2016 got some donated ICT equipment from the FG. 1 10kva Ipowerplus and 16 solar panels and 16 batteries Right of the bat, I initiated conversion with their engineers to discus optimization of the setup

They wanted 16 batteries on one 10kva 48v inverter. I told them no can do. No way u are going to parallel batteries in 4 layers. Not on my watch. I adviced them to instead bring 2 5kva Ipowerplus and reluctantly agreed to a battery slit of 8 batteries per inverter.

Next they wanted to connect 4 panels in series x2 and parallel the output. The VOC of their panels was 38v and the Ipowerplus had a max voc of 148v. Right away I told them no can do. Their setup would kill the controller. The engineer swore he usually test the PV and they never reaches 38v saying the panel voc was a figure that can't be reached.. Told him unless on a raining afternoon when the sky clears and the sun picks out.. I told him we could only use 12 of his panel in a 3 x 3 series parallel formation for each battery bank / inverter that or we procure 6 additional panels and do a 3 x 3 x 3 formation. He reluctantly agreed after all I will be signing off on the project he had no choice.
. And so it where till this day the Ipowerplus is still serving. If I had been a novice that's how the plus would of blown up and I would of blamed the hardware. Many of the issues people are having with the Ipowerplus is down to wrong configuration.
. One reason why I can understand why it is used in a radio station is due to its remarkable sub 12 milliseconds grid to backup transfer time. Allowing it to power sensitive IT equipment without disrupting or shutting them down during grid to backup transfer. No inverter (beside sukam when you activate UPS mode) has such a feature not even Victron or any if the big boy premium inverters. For those you would still need a UPS to sit in front of your equipment to prevent failure during power failure.

pranil:
Quanta Charging rate 25 %

I came across quanta manual which claims max charging rate for 200 Ah quanta AGM is 25 %. If I am reading right it means the 200 AH Qantas can be charged at 50 amps without any issues

Are my observations correct or I am reading it wrong.

Normally I have set the charges at 10 % or max 13 %

anybody has experience using such high currents 9 Life, overheating)

if the values are right then 8 Quanta can be coupled with Ipower/gennex to take advantage of their 140 amps max charge ratings even if the nepa is svailable 4 hours a day

This is totally normal for AGM most can do between 30 to 40% of C20 when charging. This is the biggest advantage of AGM batteries and why it surpasses Gel. AGM is the closest to fast charging you can get from a lead acid battery. However absorption will still slow you down although you can fast charge your way out of bulk charge within a short window.

sinistrian:
Na fangpusun o. My wallet cannot carry Victron products yet.

which software did you use for displaying the log. Victron connect? I ask because last time I checked victron released a software that slowly kills the Chinese clone hence I stopped upgrading their software for my devices. Let me know your take and experience

My stats share is about my sun set to sun raise energy use and the state of my over 2 year old 220AH Mercury Flooded acid Battery. Last year I derated the batteries to 200AH on my battery monitor to take into account sellers inaccuracy and usage degradation. pulled close to 100AH from the batteries and the idle load voltage was 24.7. Multimeter confirmed the voltage of the individual batteries at 12.35 vs 12.39 a difference of 0.4.

sinistrian:
This is the best i've ever got since I purchased the BlueSolar charge controller (after following Niyi's advice and connecting the thing directly to batteries jejely )

victron bluesolar or fangpusun

4llerbuntu:
I disagree.

As much as you have very good points about these pre-made All in One setups quality wise, completely dismissing them is disingenuous.


And I'm not surprised, I've read people dismiss Tesla Powerwall the same way on this thread.

Are you also going to claim Tesla Powerwall is crap tier 3 components?



A lot of posters here are either technicians, businessmen dealing in inverter products or just savvy DIY folks who have an interest in the technology.

So your views are understandable



But you are in the extreme minority. .000000000000000000000000000001 of the population.


The average person does not have the time, or wherewithal for all this things. The only solution for them is this pre-made setups.

And the only way solar/inverter will become mainstream is through these all in ones.

I slightly disagree with some of your assertions. Yes it is true, many of us here are in the minority and the average user in Nigeria just want something that just works without caring about the tech involved. The biggest challenge facing the growth of renewable energy in Nigeria inspite of our serious energy deficiency is ignorance. Our educational system has failed to teach energy efficiency something which should be part of basic education, the result is a public that knows next to nothing about what energy is, and how it works.. we should not be celebrating this ignorance we should be killing it which is what the forum is about.. many a novice came here without a know about solar but today have become gurus. However you need to be ready to learn. There are no short cuts in life you either pay the price to learn or pay the price of ignorance.

One solar turnkey solutions. I believe that this is the future for consumer grade solar products. Integrated all on one system that a consumer can just installed and run with little fuss.. maintenance would be handled by the solar company.. I predict a MTN LUMOS kind on .contract on a grandier scale. Unfortunately we are not at that future yet. Most of the all in one product out there are still not value for money when you start to scale. Anything above 300w and you might be better off going the traditional way.

DMerciful:
NiyiOmolyunade Sir
[b]I have similar issue with epsolar itracer struggling to track max power point when the panel voltage was 106v Vs battery voltage of 25v. Reading through the manual it is recommended that PV voltage should be twice battery voltage so I changed my configuration to 2*3 [/b]so that Vmax is BTW 52v and 60v and since then there has been improved stability and improved harvest. I sold a fangpusun flexmax to someone and he complained that the performance was low compared to his Atracer 40A epsolar, I asked him to send it back and I experimented with different PV voltages and realized according to the manual, pv voltage of times 2 battery voltage is best for the flexmax provided ur cable size is thick enuf. Now he is very happy using it and he now install for others using this standard. So different voltages for different controllers

We had this conversation meaning moons ago and I recommended you do same.. Not sure you remembered I told you so

NiyiOmoIyunade:
If you use the standard solar mount or the much cheaper but very reliable 'aluminium roof rails' such as myself or Zeestone improvised, I can assure you that there would be no heat related losses generated - the aluminium roof rails clear about 2 inches off the roof and underneath them is pretty cool because the panels would be reflecting heat off their surface. They also mount very conveniently using the standard solar roof brackets, clamps e.t.c

This is not a marketing pitch mind as they can easily be sourced off the open market at a good price - just something to consider that may be of help.


I am not a fan of mixing different panel brands except you know for sure they are nearly identical in rating, behaviour and performance - I always feel one brand would adjust voltage and amps output under load differently than the other and the least performing panel would become the limiting factor for the entire system.

See pictures of the kind of roof rails I had in mind attached.

On the first part. Even with a mounting kit roof panels still suffer from heat related loss at a greater rate compared to a ground mounted system. I happen to have and use the mounting kit in the picture you posted for my current roof mounted panel.

On the part about mixing panels. This is generally true. But if you know what you are doing and apply the appropriate derating to limit expectations then you will be fine. My panels are composed of 2 240w solarland 1 250w solarland and 1 250w my home. By maths laws should be 1160w but have been derated to 900w. Average yield from them is 800w on a good clear there, 750w on a fair day and 600 on a bad day. I have this much mix match because my system grew from 2 to 3 to 4 and each time nicking one deal here and there. I made up with ensuring there are mounted at just the sweet spot of 8 degrees tilt facing true south on a ground mounted system with about 6feet ground clearance. The ground system with all their mix matchness routinely outperforms the roof mounted system even though the latter are same exact panels.

DMerciful:
If I'm told the premium panels are 8%-10% more efficient than the tier 2 or 3 panels then I will be convinced of significant yield difference. For instance the pic attached is my harvest today from a 1.5kw sunshine panels. Meaning if I have 6kw of sunshine, I will be doing 21.2kwh......now compare and contrast! All in all, the difference does not justify the cost difference, my opinion though

Ok, I am sold on this una sunshine panel.. will pick up one from a friend today to add to my array.. taking my total to 10. I will be moving all my panels to the roof (currently have 4 ground mounted) and would need to increase panel capacity to knockout expected heated related drop in yield

NiyiOmoIyunade:
Everything Oga BigRovar has said just reinforces my conviction that flooded batteries are not suitable for solar RE applications or if they are to be used, one has to plan his charge and discharge and battery bank size very carefully.

The goal of every solar power user I have ever met is to squeeze out every last ounce of juice from his PV panels to satisfy the demands of his loads and push maximum amount of power into his batteries within the limited time frame of 1 solar charging day.

At some point in my journey with flooded batteries I throttled my charging output to 45amps when my PV panels could put out 75amps - this worked until there was no one at home to use any appliances for a while and then most of the amps would still make it to my batteries and boil them - I was not ready to be adjusting my CC amps limit on a regular basis and it made even less sense to me to just put on equipment loads I did not need just to take up the excess solar power. I remember when I kept complaining about my batteries boiling my Madam advised to leave one AC permanently on in the house and I said a point blank NO.

Give me a good Lithium or AGM or GEL any day and they will take a charge rate at 20 to 35% of their AH capacity without breaking a sweat. Heck I hear you can even charge Lithium from nearly empty to full within 1 or 2 hours.

Gel is actually worse than FLA. gel batteries will take an average of 4hrs of bulk charging @ 0.1C rate to reach about 75 - 80% SOC. At least most gel batteries. I have seen some gel claiming to have similar charge profiles as AGM. However AGM is still the best for getting the most from your PV.

earthrealm:
you still dont get it.
it doesnt supply 30amps throughout the charging cycle, once phcn is restored, it always starts with 30amps...and depending on the state of charge it will taper off gradually until it settles at 0.5amps when the batt is full.

the inverter is mustpower 4kva 48v like i have said several times. its charging algortihm is ok to the best of my knowledge.it also has an adjustable current setting, i put mine about 3/4

The 3 stage charge are Bulk, Absorption and Float. In the bulk stage every current available to the charger goes into the battery.. This is where the user has to be careful, you have to ensure you limit the current going to your battery to the recommended battery current set limit (usually set by the manufacturer) but generally 10-13% of C20 Capacity of the battery (for fla). What this means is that a 200ah fla battery should not be charged at current more than 20AH (in the bulk stage of charge) if a charger sends in 30ah to a 200ah fla battery then 10ah of the current is wasted and often times converted to heat.. causing the battery to boil and wearing off the plates. It can also lead to surface charge. AGM is much more tolerant of high current charge even in bulk stage.

earthrealm:
YOU remeber its 3 stage charging process for most indian/chinese inverters..it starts with 30amps if the battery is very low, and gradually reduces the current..and ends up with a trickle charge of 0.5amps

Then get an inverter with an adjustable charge current. I think a lot of chinese/indian inverters have that in one form or the other. 30amps is not healthy for a 200ah fla.

earthrealm:
@bigrovar, nice write up. one set of my fla in on grid 24/7. the one i complained about. grid is on for 10 to 16hrs daily, so it gets fully charged daily, though once in 2 or 3 months..i discharge it to as low as 48v or even 47.2v. mustpower max charging current is 30amps, which i hv confirmed with a clamp meter to be 29amps , so issue of excessive current is not there.

i understand the advanges of fla over smf, that is why i hv 2 sets of 4 fla batt each , just feel they should be giving me more...anyway..planning on getting a batch of smf for another installation, would use that to compare...maybe its all in my head



using cartons to differentiate fake and original is wrong, sellers can always swap cartons.

30amp is too much for a 200AH battery safe charge current should be around 20 or even 24 ah. 1 set my inverter to charge at 18ah.. the lower the charge current (up to a level) the more efficient the charge. FLA loves to be slow charged over a period of time.

mcTrinity:
please, how can you differentiate between an original and fake Quanta battery??

heard one comes with white carton. another comes with brown carton

though I'm thinking maybe they're different technologies (AGM and SMF)

Tired of all these fake versus original palava

best might be to buy from a certified dealer. Might want to reach out to the quanta people (from their website) to find out

earthrealm:
did you check what the battery voltage was when you loaded it so?.
my 4kva 48v mustpower hooked to 4 x 200ah flooded battery. the batt voltage drops to 48.8v from fully charged idle voltage of 50v if a 1.8kw steam iron + about 300w random loads is hooked up to it. i think the drop is too much, and also fully charged voltage of 50v.
when fully charged with ac, voltage is 52.6v/53.4v...and once phcn goes, it quickly drops to 52v/51.6v and later settles at a steady 50v after about 30mins to 1hr..with <100w on it....makes me think something is wrong with my flooded batts, was expecting idle voltage of 12.8v, instead of 12.5v per battery...abi its the mustpower internal circuitry and transformer that is drawing it down to 12.v?..hvnt bothered to disconnect and test the voltage of each battery when fully chared

NiyiOmoIyunade:
Your observations are correct same as Oga KieKie - Flooded batteries kind of have lower voltage profiles than sealed maimtenance free batteries and their Voltage vs. State of Charge charts typically reflect same.

I also noticed that this apparent low voltage is more pronounced in the Mercury Flooded I first had than in my last set of US Batteries for example but I have no hard data to support this.

Interesting that you also are getting disillusioned with Flooded batteries as a quite a few people have been on here - for me Lithium is the next port of call once I wrap my head around all the complexities of a BMS and battery balancing.

To eliminate undercharging issues with your Flooded battery bank please Can you confirm that you give your batteries a proper daily charge? What is your absorb voltage setpoint? How many hours do your batteries spend in absorb daily?

Currently I have 16 pieces of 12v 200ah Gel batteries in a 48v 800ah setup - my voltage generally stays around 50.6 worst case by 6am in the morning. If the Madam had used microwave a lot the night before or the 2hp sitting room AC then I could see 50.3volts - once on a cloudy day where I could not finish absorb and still had heavy overnight usage, I saw 49.75volts by 6am in the morning and mind you I ALWAYS use the 1hp bedroom AC overnight.

So I remove anywhere between 160ah to 260ah between 6pm and 6am daily from a 800ah bank and the voltage stays within the 70 to 80% State of Charge mark.

So far so good excellent batteries and they were sourced from ICelllPower through JUO.

One thing I have learnt going 2 years into using FLA battery is, they have a different load and open circuit voltage profile when compared with SMF VRLA batteries. This should not be taken to mean FLA are weaker (In fact the reverse is the case).

Lets get one thing out of the way. Voltage is a not a good indicator for deciding state of charge. The closest means of determining battery state of charge via voltage is when the battery is at rest for close to 2 hours (no charge or discharge). I have 2 mercury FLA (The once popular tubular type) 220AH (which i derated to 200AH after a year of use) both batteries are connected in series at 24v. I have a Victron BMV to monitor battery voltage, and does net amps charge/ discharge.

My observations:

FLR has a very low pull down voltage when load is applied compared top VRLA/SMF batteries.. BUT it bounces back once the load is removed and if in the end you leave both batteries for 2 hours without load or charge. Their OPV would end up to about the same. I think the difference in pull down voltage is largely due to their chemical composition. My average discharge from my "200" AH 24v bank is 84AH over 2 years (figures from Battery monitor stats) which represent about 42% depth of discharge. Most of the discharge happens between 17:00 to 08:00 with a discharge rate of about 4AH - 9AH depending on the time of night. By most morning battery *load* voltage is at 24.6 - 24.4. I once pulled about 103AH from my battery bank and the load voltage was at 24.4v in the morning. Once I removed the load the battery voltage jumped to 24.7 and in 30 minutes was at 25.1v. The nature of FLA gives it a very elastic voltage.

I have also noticed flooded acid suffers a lot from surface charge:
I noticed this when my battery voltage suddenly dropped (if we recall many members have complained about this before) in fact load voltage dropped considerably from the usual 25-24.9 voltage in early evenings to about 24.7. I was already thinking it's time to get a new battery when I stumbled on the surface charge syndrome.

Surface charge

Lead acid batteries are sluggish and cannot convert lead sulfate to lead and lead dioxide quickly during charge. This delayed action causes most of the charge activities to occur on the plate surfaces, resulting in an elevated state-of-charge (SoC) on the outside.

A battery with surface charge has a slightly elevated voltage and gives a false voltage-based SoC reading. . Surface charge is not a battery defect but a reversible condition.

source http://batteryuniversity.com/learn/article/water_loss_acid_stratification_and_surface_charge

Surface charge is when the charge activity on a battery occurs only on the surface of the lead and does not goes deep.. cooking metaphor. It is like meat that is only cooked on the outside but deep inside is uncooked.

What are the cause of surface charge:
High current charge. Lead acid batteries have an optimal rate of charge which is usually 20% of C20 capacity for AGM and 10-13% for FLA. The relative lower charge rate for FLA makes them more susceptible to surface charge. If a 200AH fla battery is charged with 40AH.. this would lead to the charger getting to a false absorption voltage faster than it should leading to it getting to floating (thinking the battery is fully charged) when in fact only the surface of the battery lead was charged.. when load is applied and the surface charge is used up.. you will experience a drop in battery voltage.

Cure: is simple, longer, slower charge. Just as slow cooking meat with low heat allows it to be well and deeply cooked. slow charging a battery within its recommended charge current will also allow the charge get deep into the lead plates. Unfortunately this is problem with solar only source of charge. Effective sun time might not be enough to fully cure a battery that has suffered from surface charge. slow charging means less energy pumped into the battery for a longer time.. longer than the sun can be in the sky. The medicine for this is to lower your battery depth of discharge based on how easy it is to effectively charge it based on its recommended charge rate (and not based on your panel capacity) It is also why it is better to go for higher voltage than higher amps when designing battery systems.

In my case, I had to bring back grid charging at night and stop the habit of only charging my battery via solar. Now I charge it everytime grid is available. Sometimes when battery is full. I turn off the charger for a while (so that the charge sinks in) and then turn the charger back on like 20 min later. since applying this my 2 year old FLA stays north of 25v most nights even on a sustained load of 11AH.

I still think that FLA are the best lead acid batteries out there. They are more rugged, tougher and easier to troubleshoot. The ability to renew the water in case of loss allows it to take a beating and abuse from charges and equalization helps to remove the need for battery balancers and help combat sulphation.

earthrealm:
LOLZ, that doesnt prove anything. why dont you start your car, remove your battery and run the ac for 10mins @high fan speed. observe it.
then compare it to when the battery was connected...and report back to us.
the electrical loads on a car are designed to run off the car battery, thats why your batt will drain if perchance the batt head terminals are loose/pull off while driving

imagine this scenario...a solar system with loads pulling say 500w off the bank..and same being replaced by the solar panels. and another one with say 50w load being taken from battery and 50w being replaced by the solar panels concurrently. which of the batt bank do you think is doing more work/will age faster.

i agree that ac usage on car battery is minimal, but denying that such impact exists is an untruth.
you may google further for clarification. lots of varying opinions on the web though..

The scenario in bold not how battery charge and discharge works. You can not charge and discharge a battery at the same time. If you understand the chemical process behind conversation of electrical energy to chemical energy and verse vesa you will know the process can only go one way at a time. Besides, elecricity follows the path of least resistance which is always the load.. everything coming from the charger goes to the load, the reminder charges the battery, if the charger is not enough to power the load, the reminder is taken from the battery. The battery terminal is a busbar in this case

earthrealm:
AC DOES DRAIN CAR BAttery,[for cars with dual cooling fans, bboth fans come on with ac = bigger electrical load] even headlights too...the alternator works harder when these are on. to keep up with the sucked out juice.
since one cant equalize a car battery insitu, above whatever the alternator can do, a good desulphator should prevent the plates from clogging up.

I have done extensive read on desulphators and almost every article claims it all sneak oil. There are few research work into the claim it works but the few I have seen especially from here http://www.quan-diy.com/misc/desulfator/infinitum.htm all points to the fact that desulfators are sneak oil. Battery balancers on the other hand are undisputed proven technology.

c0ogumo:
Trina Solar Panel 255W Poly still in stock

Warning: Coupon is either invalid, expired or reached its usage limit!

Also you might want to work on the process of checkout. It requires the user to be registered (you can't checkout as guest) and the registration page throws up a json error

Ijeoma660:
Its so funny after the first rain on Friday, I was fiddling with my panel voltage points and noticed one of them reading 10volts. I was really worried if one of it is already degrading.

Fast forward to Sunday morning. I was peeping at my construction from upstairs. [my panels are low lying and are accessible without climbing any support] Low and behold, the first rain of the year had built a thick sludge around a section of the panel, giving it a serious voltage drop.

From test and experience a liitle shading of very insignificant parts of the panel can cause a great drop in yield. As I was warming up to connect a hose to send away the 'mole' munching at my solar yield, then came the heavy downpour.

Sorry fellow enthusiasts as y'all were crying over poor yield I was seeing a natural washer-man coming along to wipe clean my peevees.

JUST IN - Everyone in the house now is gradually appreciating the beauty of free energy especially ladies. They are all asking questions bothering on knowledge transfer. I am feeling so good, they are all learning fast!

hoping the only thing that is transferred is solar knowledge..

4llerbuntu:
why is this not even a mainstream thing?

i've often wondered why there isn't some system that cuts off the inverters discharge when the batteries get to a particular percentage...

Such systems already exist especially with premium (code for very expensive) offgrid solar equipment Some Inverters, and Hybrid Inverters come with built-in low battery disconnect. The reason why you don't see it everywhere is because determination of a battery state of charge is not as easy as ABC. Battery state of charge can be very complicated and is a product of the the Age, rate of charge/discharge, temperature etc. All the above have to be guessed right and its never easy. This is why it is best to design your system around ensuring it is cycled between 40-35% of the battery capacity. That way you won't have to worry yourself about Low battery disconnect systems.

Barezzi:
I agree with you on all counts baba... It's the reason I'm still waiting for price crash before going Lithium

Lithium prices would reduce to a point then it would go up. Lithium is a rare earth material concentrated in few places of the world. Once it goes mainstream it comes gold and the value would shoot up higher than manufacturing process can reduce. I am average lithium prices will not be crashing in a long time