NiyiOmoIyunade:
One thing that also came out to me was that given a series of low sun cloudy days with poor solar yield where I get only 4kwh daily and no help from the grid, I can flog my 800Ah Lead Acid bank 15Kwh between sunset and sunup for 3 days straight without service interruption whereas Oga Dapsyra with his 400Ah LTO acquired for maybe three times the price of my Lead Acid would probably conk out by the end of day two except he throttles back his consumption.

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.

NiyiOmoIyunade:
I think Oga GeorgeD tried to account for the differences in AH capacity requirements between Lithium vs. Lead Acid - he derated the Lithium AH requirement vs Lead Acid by 50% - only issue Oga Chris pointed out was that he chose SimpliPhi as his Lithium battery representative case which he deemed too expensive and non-representative of the average Lithium price.

It appears you want to derate the AH for Lead Acid vs Lithium comparison by a factor of 2/3rds and I assume this makes sense for a max daily 30% DoD scenario for a Lead Acid battery to achieve maximum cycle life. Oga GeorgeD appears to prefer a max daily 50% DoD assumption which is in line with what most people can practically afford to do.

The point I am making is that Lithium batteries are not invincible - care has to be taken in selecting an appropriate battery technology to use for any scenario especially so given their steep purchase price.

Barezzi:
@GeorgeD1,
If i remember correctly, the conversion is not 1:1 It's more like 3:1
A 300Ah Lead Acid (LA) battery bank is roughly equivalent to a 100Ah Lithium bank.

Your current LA capacity is roughly equivalent to a 260Ah Lithium bank... about N6m using your example.

Remember that your 780Ah bank has a usable capacity of 390Ah. A 300Ah Lithium equivalent should give you better value.

Correct me if i'm wrong @chris81964/dapsyra, you can grow your Lithium bank gradually. Start with 100Ah, and grow to 300Ah at anytime.
Unlike LA where one is limited to a max 3-month window to add new batteries.

bigrovar:


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.

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.

GeorgeD1:


barezzi,
this is getting quite interesting, isn't it? if 300ah for lead-acid equals 100ah for lithium it then
means we have to ultimately change the way we calculate our power fundamentals, i.e p=iv.
unfortunately i'm yet to see any documentation in support of this. i'd be happy if you could give
any references. at least that would be a good starting point.

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.

earthrealm:
...if i state my supercar/range rover allegory, some people will vex again

GeorgeD1:


barezzi,
this is getting quite interesting, isn't it? if 300ah for lead-acid equals 100ah for lithium it then
means we have to ultimately change the way we calculate our power fundamentals, i.e p=iv.
unfortunately i'm yet to see any documentation in support of this. i'd be happy if you could give
any references. at least that would be a good starting point.

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.

makavele:


Let me chip in from behind the curtains..

I guess he mean't to say 100ah lithium is equivalent to 200ah lead-acid . .
Because while you can only take LA batts as far as 50% to stay in shape; you can take Li batts down to 0%.
But what he failed to understand is that it is cheaper . . buying 300ah LA batts vs 100ah Li batts . .
For now,the expensive price and little practical facts does not do justice to dumping the traditional lead batts.
The "exaggerated" 50,000 to 100,000 cycles for now is merely hypothesis arrived at with extrapolated data
The true test would be using them for 10 years and see how the hold up . .practically I mean

Barezzi:
Plenty on google...

1. https://earthxbatteries.com/wp-content/uploads/2016/07/SLA-vs-Lithium-Ah-AN1506_New.pdf
2. https://www.victronenergy.com/blog/2015/03/30/batteries-lithium-ion-vs-agm/

JUO:
Flex max 80a fangpusun 160k
Flex max 60a fangpusun 126k
50a-12/24v 45k. 45k
50aD-12/24v 60k
60a-12/24v/36v/48v 90k.
60aD-12/24v/36v/48v 115k
70a-12/24v/36v/48v 100k
45a-12/24v/36v/48v 70k
30a-12/24v 33k
Battery balancer Fangpusun 24v-25k
MPPT- CONTROL 16K
epever 30a+MT50 12/24v (CN) 48k
epever 30a 12/24v 38k
epever 40a 12/24v 55k
BMV 702 FANGPUSUN 42K
BMV 700 FANGPUSUN 38K
Watts meter with clock and 50Hz/60Hz
Monitor Analyser 7k
PROGRAMMABLE Digital timer 15/16a 5k din rail
PROGRAMMABLE Digital timer 25a 7k din rail/wall mount
080-987-337-09

makavele:


Then how would you handle current in excess of 200 Amps; for a super large battery bank
You want to get cremated before your time, brov ?

earthrealm:


so with battery balancer, and or desulphator/equalizer, series batteries will still go out of sync??..how.. why?
24v setups have limitations which require more funds to surpass.

on the lithuim battery setup, maybe some of us are off grid or something. technology is evolving, am fairly certain within 10yrs abetter form of battery/energy source will be discovered, and 1 is now stuck with an expensive antique, a lead acid battery system or agm if properly sized and managed can go 7yrs plus, georged1 setup is a case in point, so why reinvent the wheel.??

if i state my supercar/range rover allegory, some people will vex again

GeorgeD1:


barezzi,
this is getting quite interesting, isn't it? if 300ah for lead-acid equals 100ah for lithium it then
means we have to ultimately change the way we calculate our power fundamentals, i.e p=iv.
unfortunately i'm yet to see any documentation in support of this. i'd be happy if you could give
any references. at least that would be a good starting point.

DMerciful:
200A? Na printing press? Most inverter users... What's their average load?

makavele:


Let me chip in from behind the curtains..

I guess he mean't to say 100ah lithium is equivalent to 200ah lead-acid . .
Because while you can only take LA batts as far as 50% to stay in shape; you can take Li batts down to 0%.
But what he failed to understand is that it is cheaper . . buying 300ah LA batts vs 100ah Li batts . .
For now,the expensive price and little practical facts does not do justice to dumping the traditional lead batts.
The "exaggerated" 50,000 to 100,000 cycles for now is merely hypothesis arrived at with extrapolated data
The true test would be using them for 10 years and see how the hold up . .practically I mean

nonoski:
So I finally finished my connection over the weekend and have been monitoring the results.

Here’s my story.
It will help a lot of people venturing into RE.
My setup for now is 12 panels rated 300watts (3600w) each in 3S4P connection.
I already had an inverter and 48v x 200Ah battery bank (Bluegate VRLA Batteries). The batteries are 13 months old.
Before powering my charge controller (Outback FlexMax 80) and connecting my ZHC equalizer on Saturday I decided to check the reading of the batteries
Battery 1 – 12.2v
Battery 2 – 12.2v
Battery 3 – 12.2v
Battery 4 – 10.2v
The inverter I have been using has a maximum charge voltage of 53.4v (13.35v per battery) and a maximum charging current of 11.4A.
It took me over 10 months before I realized the inverter was undercharging the batteries basically because we had PHED light for at least 21hrs a day throu out last till January this year when we now go weeks without having light. So the inverter neva really went beyond 50% DOD. Infact it was on this thread I learnt that 53.4v is not a good charge voltage.
From my little knowledge of batteries I already know most of those batteries are sulphocated and may need to be changed soonest.
Since I powered my Outback CC midday Saturday till today Monday I haven’t seen more than 6.2KWH which I consider quite poor for a 3.6kw setup. (Thoug there wasn’t any sunshine throu out Sunday in ph).
But today Monday was all sunny and that was when the CC recorded 6.3kwh which less than 45% efficiency rating of the panels.
The incoming Amps didn’t go beyond 20Amps. I am beginning to doubt the rated output of the solar panel coz I was expecting at least 65-70% efficiency. I will be doing a string by string test tomorrow and Wednesday just to be sure.

Now I bought the Inverter and the solar panels (early last year 2017) from a known solar dealer here in Port Harcourt who came highly recommended. He is always on radio talking about renewable energy, in my office he is one of the main contractor for solar installations.
After I noticed the inverter was charging at 53.4v I decided to engage him on the issue.
I was both amazed and disappointed coz the guy is both empty and unknowledgeable compared the folks here on Nairaland. After much question I deduced that he just went to China and shipped in lots of solar panels and inverters. He isn’t even aware his inverters undercharge batteries.

My advice to those who want to go into RE to do a lot of research and triple check anything they want to buy. Check for reviews for any product they want to buy to be sure.
Contact the guys here, there are far more knowledgeable that all these clowns masquerading as solar expert. I don’t blame anybody who refuses to go into RE coz its quite heart breaking spending millions and within a year or 18 months everything fails.

My Solution: (I am learning the hard way)
I will be changing my inverter to a mustpower 5kva inverter (30a charger)
I will gradually phase out all the batteries I’m currently using and increase it to 48v x 400Ah by July
If the solar panels are also found wanting they too will be phased out gradually before February next year.
My goal is to achieve at 75% freedom from PHEd and their nuisance.

kiekie1:


Good morning Nonoski,
How did you tackle the issue of the bluegate battery reading below 11v ? What is the name of solar panel & did you run brief individual test on solar panels before mounting them ? Was there marginal variations in the individual string readings in the combiner box? Are the panels shaded in anyway whilst operational ? Was mc4 connectors used ??
Ceteris paribus, you will surely enjoy your set up ! Cheer's

pranil:

My earlier long post on the issue was swallowed by the Nairaland gremlin and I got banned for 24 hours I wonder why?

But in general, comparing lithium on installed price is not correct . for that matter any energy producing device is not priced at purchase price but on LCOE ( Levelized cost of electricity ) essentially price per kWh ( for detail understanding with Nigeria context)

1. True cost of LCOE .pdf
2. what is LCOE ( BNEV)


https://www.dropbox.com/sh/2i8lq9fo7mqh3dx/AAB39JNif_f-0FUZ68q4jz23a?dl=0

in my own case, the LCOE of BYD came to 50 NGN/KWH while trojan 12 V came to 55 and trojan 2V came to 45 NGN/KWH

This was including the cost of additional bms, shipping, customs stec. - I posted a simplified excel sheet with zero discounting a while back for those who are interested.

for me, there were two very big incentives - the convenience of not having to babysit the battery ( my other setup has flooded lead acid) and superfast charging ( since I also use the Diesel generator to charge on extended grid failures in the night )


What is also to be factored is the reduction of required PV panels - Due to fast charging and higher efficiency and absence of periodic equalization you can get away with 20 to 30 % smaller array for the same KWH of usable capacity

please refer to attached pdf ( lead-acid batt efficiency)


quote " - zero SOC to 84% SOC the average overall battery charging efficiency is 91%, and that the incremental battery charging efficiency from 79%to 84% is only 55%. This is particularly significant in PV systems where the designer expects the batteries normally operate at SOC above 80%"


finally, the choice of technology depends on the usage pattern but in general, Lithium makes sense currently in the application of peak reduction or timeshift of energy use . as a pure storage lead-acid will be the king for a quite a while till alternate technologies catch up

p.s interesting side note to the debate - On Sunday I noticed that small generators ( 2.5 kw to 7 KW) sold by Games in Jabi, Abuja have been fitted with lithium batteries as starter battery instead of standard SMF battery - There cannot be a worse application in hot temperatures than a generator starter battery

nonoski:

I changed the position of the battery and used the charge controller to carry out equalization at 60v for 2hrs plus I connected ZHC battery equalizer.

Since Saturday the battery bank that couldn't last 6hrs (usually goes of by 5am) now last more than 9hrs till sunrise (with more load). So for now I think I will manage them till the end of the month when I will start changing them in pairs.

I tested all 12panels and they had similar readings + or - 2v.
The 4 strings almost same reading + or - 0.2v (101v to be Precise)
But I don't have an Amp meter to know the exact amperage of strings coz on the CC it's shows less than 18amps while I'm expecting at least 30-36 amps.

Yes I used Mc4 connectors I bought from Amazon and kept running test to make sure all the connections were Ok.

Will test each string this morning when the sun is up

NiyiOmoIyunade:
Since you have a combiner box, you can simply switch off all breakers for all PV strings and switch them ON one at a time and use the AMPS output reading at your CC screen to see what each string of 3 panels is putting out. That way you can see if any string is underperforming relative to the others - this is a cheap workaround for your lack of a DC clamp meter.

Be sure to have a sufficient constant house load ON and PHCN/Gen OFF at the time of testing so the panels are giving their maximum juice and of course do it when the batteries are drained and charging at bulk stage.

The extra backup hours you are getting is a result of proper charge voltage unwinding some of the sulphation your batteries have suffered and one possible reason why your solar output is low is because your real battery capacity is being limited by the one bad battery in the string.

Given 4 12v 200ah batteries in series to make 48v 200ah. If one of the batteries (the one reading 10.2v) has capacity reduced to 80ah for example then what you have is a 48v 80ah battery bank and this is how your batteries will behave under charge and discharge with the extra consequence that the 200ah batteries in the string will overcharge and boil out and slowly lose capacity just like the one bad one.

You really can't equalize mismatched capacity sealed batteries in series. All you will be doing is boiling the good batteries in the series string. Isolate the one bad battery and give it a proper charge and then assess its capacity.

nonoski:

Thank you very much
I have already done the string by string isolation and notice one of the strings is faulty (maybe due to wiring) so I put off the breaker so for now it's just 3S3P.

The thing is there has been Phed light since Friday till now so the batteries haven't really been drained so I can really tell the output of the CC.

Oshomo12:


I want to believe one of the reasons for you to go solar is to reduce what u consumed from PHCN. So during the peak hours of sunshine, just put off ur PHCN supply and check what ur system will give u.

Oshomo12:


I want to believe one of the reasons for you to go solar is to reduce what u consumed from PHCN. So during the peak hours of sunshine, just put off ur PHCN supply and check what ur system will give u.

pranil:

My earlier long post on the issue was swallowed by the Nairaland gremlin and I got banned for 24 hours I wonder why?

But in general, comparing lithium on installed price is not correct . for that matter any energy producing device is not priced at purchase price but on LCOE ( Levelized cost of electricity ) essentially price per kWh ( for detail understanding with Nigeria context)

1. True cost of LCOE .pdf
2. what is LCOE ( BNEV)


https://www.dropbox.com/sh/2i8lq9fo7mqh3dx/AAB39JNif_f-0FUZ68q4jz23a?dl=0

in my own case, the LCOE of BYD came to 50 NGN/KWH while trojan 12 V came to 55 and trojan 2V came to 45 NGN/KWH

This was including the cost of additional bms, shipping, customs stec. - I posted a simplified excel sheet with zero discounting a while back for those who are interested.

for me, there were two very big incentives - the convenience of not having to babysit the battery ( my other setup has flooded lead acid) and superfast charging ( since I also use the Diesel generator to charge on extended grid failures in the night )


What is also to be factored is the reduction of required PV panels - Due to fast charging and higher efficiency and absence of periodic equalization you can get away with 20 to 30 % smaller array for the same KWH of usable capacity

please refer to attached pdf ( lead-acid batt efficiency)


quote " - zero SOC to 84% SOC the average overall battery charging efficiency is 91%, and that the incremental battery charging efficiency from 79%to 84% is only 55%. This is particularly significant in PV systems where the designer expects the batteries normally operate at SOC above 80%"


finally, the choice of technology depends on the usage pattern but in general, Lithium makes sense currently in the application of peak reduction or timeshift of energy use . as a pure storage lead-acid will be the king for a quite a while till alternate technologies catch up

p.s interesting side note to the debate - On Sunday I noticed that small generators ( 2.5 kw to 7 KW) sold by Games in Jabi, Abuja have been fitted with lithium batteries as starter battery instead of standard SMF battery - There cannot be a worse application in hot temperatures than a generator starter battery

Wazari:
Hi Pranil,

I find it incredible that you have been able to achieve an LCOE of N45 - N50. I have not seen anyone in Nigeria do lower than N80/kwh for a residential solar PV system with storage.

I looked at your old spreadsheet but it looks like you only accounted for the direct and associated costs of the battery, not the complete system. Am I mistaken? Please, I'm very interested in your figures to see how you arrived at N50.