Charge controller problems in Africa

System · August 2007

Hello All,

I'm in dire need of some help from across the atlantic so all advice is appreciated.

This is my first post so I am going to give some background info. I have been a licensed journeyman electrician in New Mexico for the last five years but I have been living in the Islamic Republic of Mauritania for the past year volunteering for the Peace Corps. We have some solar sites here that I need advice on. Also let me say that I didn't install any of our solar power systems and I don't have any experience in solar.

With that said:

We have four rural solar sites at our girls mentoring centers that power 3-5 computers, 1-2 flourescent fixtures, and 1-2 ceiling fans. Two panels are generally installed (I don't know the wattage but the paperwork says 165W apiece) along with one 30A 12V charge controller, one 235AH 12V deep cycle and a 500W 12V inverter. We are having problems burning out charge controllers. At one site, I think 24V panels were installed (I measured ~38V coming off each panel at midday) instead of 12V (the battery, inverter, and controller are all rated for 12V). At another site I'm not sure what is going on. We had a couple charge controllers burn out before I had a chance to look at it and when I got there I measured ~22V coming off each panel at midday.

What confuses me is the voltage; how much should a 12V panel output? Mauritania is on the western side of the saharan desert so sun isn't a problem (although it regularly gets over 120degF). Also, doesn't the battery regulate the voltage up to a point? The inverters have internal overcurrent protection although if I'm not mistaken, they are ridiculously undersized. 6AWG wire is installed on the entire DC side.

What should I be looking for and repairing? It generally takes two days to get to these sites and once I'm there I need to make sure I can fix all problems that I may encounter. Funds are limited but my priority is to do it right this time so no more major problems happen further down the road.

Sorry for all the questions and thanks in advance for any responses,

Powerless in the RIM

mike95490 · August 2007

Re: Charge controller problems in Africa

Panels are typically about 18V or thereabouts. Batteries have to charge at almost 14.5V at one point in the cycle, and you have a couple of volts loss when inline with the controller, and if the panels are hot, they loose voltage, as temp goes up.
Do you have a MFG/model # for the controllers ?

At the least, have the batteries been refilled with distilled water all these years ?

If you have a reliable Digital Voltmeter, you can temporarily bypass the controller, and babysit the PV & batteries till they are charged.

Sounds like you will need some sort of controller that will accept 40V input to charge 12V batteries. This is typically an expensive style of controller, or your 2 panels got mis-wired and ended up in series, and not parallel. (was someone messing around, and put it back wrong ?)

niel · August 2007

Re: Charge controller problems in Africa

yes please do tell us what controllers are there that seem to be blowing out. with knowing the wattage from the pvs i think we can say that the pvs are 24v pvs as i know of no 12v pvs that fit that wattage range. i know you are confused somewhat on the voltages that are supposed to come from pvs at their respective operational voltages. the operating voltage for 12v are typically from 16.5v to 17.6v(listed as vpm and vmp) and these will have open circuit voltages well over 20v. the higher voltage battery systems will have pv systems that are generally multiples of the pv operational voltages shown. for example: 24v pv may have a 35v vpm. you could see the specs on pvs to know what general system they are best designed for for individual pvs. pvs can be put into series and parallel so the voltages and currents can be raised to suit other design parameters. being the pvs are 24v designed and the battery system is of the 12v design the controllers will have to be of the voltage downconverting type of mppt controllers. if you are replacing this type of controller with one that is only designed for 12v in and 12v out along with 24v in and 24v out and no downconverting, this could blow out the controller if in 12v mode or not charge when in 24v mode. not all controllers downconvert and that is what you need from a controller. these are more expensive controllers and you should also have a battery temperature sensor to track those high temps you are getting that will adjust the battery charging voltages as needed and speced by the battery manufacturer.
i think you've got the general idea of the pvs and controllers and you are right that batteries will regulate voltages to a point. that is why there isn't any need to regulate the voltages while in the bulk charge mode. if you continue charging any battery without voltage regulation, the voltage will continue to rise until it reaches the charging voltage source's open circuit voltage as well as continue feeding the battery current beyond the full charge point. currents may have to be regulated or controlled in bulk charge mode if the currents far exceed battery manufacturer's recommendations so that the batteries do not charge too fast, but this isn't a normal regulation that's needed in solar because not many of us buy excessive numbers of pvs to have to do this and we could disconnect pvs as well. when the charge reaches about 80-90% the absorbtion stage occurs. this is where the voltages are held from being exceeded and currents tend to decline as charging continues. batteries should not be allowed to exceed their voltage design parameters or enough damage to the batteries will occur to take away from their normal lifespans or kill them in quick order depending on how badly things were exceeded. the last stage of float charge is a minimum of voltage/current to keep the battery from discharging or exceeding 100% charged so it maintains the battery at 100%.

System2 · August 2007

Re: Charge controller problems in Africa

The charge controllers we have been using are Super Vusa Scanner 300W/30A. Pretty cheap, even for here. I have located the charge controller we would need to convert the voltage but I haven't located it here. I might just get it sent over in a diplomatic package. The only other option would be to locally purchase either new panels or new batteries/inverters/controllers which would be more expensive and be more work.

It does sound like the one site might have 12V panels (22Voc). Any speculations on why the charge controller might be blowing at this site? I opened all of the blown controllers from this site (the solution before I got here was to keep replacing controllers) and the same six capacitors (I think they are capacitors) have overheated and melted down on every one.

I did get up on the roof to make sure the panels weren't in series by disconnecting them and measuring them individually.

Lucky for me the person who installed the pvs was adimit about keeping the batteries full to the point that she included a homemade distiller at each site so the batteries have been kept topped off.

Another question. How do you accurately measure battery voltage when there is no load?

Thanks for helping!

mike95490 · August 2007

Re: Charge controller problems in Africa

RIMSolar wrote: »

Another question. How do you accurately measure battery voltage when there is no load?

I use a reliable voltmeter.

Let the batteries finish an equalize cycle ( or an hour or 2 of vigorous bubbling) to insure they are fully charged. Remove all loads, and wait a couple hours, then read the voltage. This lets the "surface charge" dissipate, and you can read the "real" charge.

Measuring voltage with a load is problematic, because you don't always know how the older battery will react with load, but thats the simple way to test an automotive starter battery, AE batteries don't see the cranking amps load that automotive batteries see, so that sort of test is invalid.

niel · August 2007

Re: Charge controller problems in Africa

"It does sound like the one site might have 12V panels (22Voc). Any speculations on why the charge controller might be blowing at this site? I opened all of the blown controllers from this site (the solution before I got here was to keep replacing controllers) and the same six capacitors (I think they are capacitors) have overheated and melted down on every one.

I did get up on the roof to make sure the panels weren't in series by disconnecting them and measuring them individually."

"I have been a licensed journeyman electrician in New Mexico for the last five years but I have been living in the Islamic Republic of Mauritania for the past year volunteering for the Peace Corps."

"I might just get it sent over in a diplomatic package."

i tried to look up the controller you mentioned, but i cannot find it. in any case, going on the roof and measuring individual pv voltage outputs doesn't mean there isn't a series wiring. an electrician would know the difference between a series wired item and one that is paralled. i know you are green on that system as well as solar, but it is obvious that you weren't the only one in the dark for the one who put it all together isn't too knowledgable either.
you said you have to get parts through diplomatic channels? are you in a black listed country due to too much fraud and theft? i do not wish to continue helping if that is the case as that would explain why there is a potporri of items that nobody seems to know what to do with. the place of purchase of those items should be able to continue helping you. they are being bought from somewhere aren't they?

System2 · August 2007

Re: Charge controller problems in Africa

For starters, this is how you quote someone

niel wrote: »

i tried to look up the controller you mentioned, but i cannot find it. in any case, going on the roof and measuring individual pv voltage outputs doesn't mean there isn't a series wiring. an electrician would know the difference between a series wired item and one that is paralled. i know you are green on that system as well as solar, but it is obvious that you weren't the only one in the dark for the one who put it all together isn't too knowledgable either.
you said you have to get parts through diplomatic channels? are you in a black listed country due to too much fraud and theft? i do not wish to continue helping if that is the case as that would explain why there is a potporri of items that nobody seems to know what to do with. the place of purchase of those items should be able to continue helping you. they are being bought from somewhere aren't they?

WHOA there niel.........you're a (edit by niel)! I would definitely say it's time to move out of your mom's house, 51 years of living with her as the only woman in your life has made you quite grumpy.

You can never assume anything by just looking at it.....especially in Africa......which is why I disconnected the panels. Series wiring gives additive voltage thus if the voltage is the same when they aren't wired together....they were in PARALLEL (I also popped off the junction box on the back of each panel to make sure there wasn't any series wiring that could be changed but thanks for asking).

Thanks for not wasting any time insulting my professional credentials too, that was really classy, sounds like you are green at being a MODERATOR (you should really look up the definition of that word by the way).

Just because you can't find something on the internet doesn't mean it doesn't exist although you probably believe everything you read on the internet too.

I also told you what country I live in (Mauritania--you can find THAT on the internet) and it's not black listed or else they wouldn't send Peace Corps here (and black listed from what exactly?). Diplomatic packages are just cheaper to ship.

At least we are on the same page on one thing, I do not wish you to continue helping me either (although I do appreciate mike's help).

niel · August 2007

Re: Charge controller problems in Africa

talk about assuming, i was asking you questions and not accusing. some things said by you made me want to question you as some of what you say doesn't add up right. it all doesn't matter as you should be approaching the people from where it was all bought from or at least dig up the manuals that came with the stuff if it is still there. many of those are on the web too and if you read i said that it didn't matter if i found it on the web. anybody, including myself, can question where somebody is coming from. if you got the wrong impression and my questions are unfounded then i am sorry about that, but you must understand there is a great deal of theft that takes place from country to country and even within this country. many steal first and figure it out later and it is not beyond reason to assume that some would try to get help with the stuff here.
btw quotes are quotes and if i choose not to include all of the message in that manner that is my personnal prerogative. my mother said you're welcome anyway.:)

nigtomdaw · August 2007

Re: Charge controller problems in Africa

Hey guys lets just chill, ..............firstly you get nowhere at all RIM by calling people freaks, fact ! Niel has a heart of renewable energy gold and your earlier posts as a 5 year journey man electrician did give me cause for concern !!, you need to focus on your problems and describe them much better. People like Niel, Creezer, NAWS, boB ,Solar Guppy ,Vic , Wayne, BB,Lamplight and so many others are the life line of places like this and should be respected. It must be quite simple for them to say..... Hey didnt I answer that question last week, cant be bothered !........ but they dont and plough on regardless trying to help everyone,with a problem,,,, Niel made an asumption and was maybe wrong but your abuse was harsh and unwelcomed, unfounded and distasteful, did he cut too close to the bone ?.... If your reply had been tempered balanced and educated (are you still are in the peace corps ?) .... rather than to simply abuse.... you would have possibly had more success, I doubt you will receive much help now ? , but I will not be surprised if you do, nobody likes to see someone genuinely struggling ....but moderators, site owners and guru solar experts are all here to help and dont deserve the triad of abuse you levelled, I can easily see where Niel was coming from.................. you are out of line ! in your reply.... if he added 2+2 and got 5 so be it.......... but an apology is in order mate!
Try
Sarcasim it can be funny witty and even amusing and you still get help......but your comments were personel and in bad taste, IMHO

Nigel.... still got lots to learn love the forum !

mike95490 · August 2007

Re: Charge controller problems in Africa

I'd looked up Mauritania right off, and saw no "weirdness flags". After Niels post, I looked up the state dept, and no red flags there either.

We do have valid concerns about stolen gear being configured by thieves, but I didn't get that twitch either. So I'll keep giving advice as I can. I don't have much experience beyond grid-tie, but do know you will need some fancy controllers to make full use of the wattage you have. If you use "normal" PWM controllers, you loose a fair amount of power, AFIK, but they cost $100 ea, vs $300 or so for MPPT controllers. I can't recommend any, because I've not used any.

As to the caps blowing up, there WAS a problem in the computer industry a couple years ago, with motherboards, with counterfeit caps - a worker left a cap factory, for a new employer, and brought the secret recipe with him. But he forgot a couple pages about treating the aluminum case, and in 3 years, entire lines of motherboards were failing. warranties were fudged, class action suits, and the whole ball of wax. Perhaps, some of the counterfeit caps ended up in the current charge controllers ?? Or maybe not.

System2 · August 2007

Re: Charge controller problems in Africa

You know what they say when we assume? It makes an "ass" out of "u" and "me".

Anyways, Niel, I accept your apology but if you look back, the whole first half of your reply was accusations and insults and not questions. I think you might have jumped the gun a little bit there. Maybe I did too in my reply and my apologies to you and your mother

(accepted and please look back as you'll see question marks after 3 sentences. that mark does constitute a question and not a statement. added by niel)

The quotes jab, I agree, was half-assed, although I still laugh every time I read the "living with mom" one liner.

My reference to my journeyman's license was just to give you some background information on where I'm coming from (mostly code based wiring without much theory), I still don't understand why it would have raised any flags.

Mike, you might be on to something, I just might have to shop for a better quality controller. Mauritania doesn't exactly have any quality control and we do tend to get everything that doesn't pass QC in the EU.

Oh, and Nigel, YOU'RE A (edit by niel)!!!! (no more name calling so knock it off already. added by niel)

Iya · August 2007

Re: Charge controller problems in Africa

Hello RIM,

Nothing to do with solar thing but I can explain why the suspicion of the diplomatic package.

I come from a developing country so I know how 1st world countries people view certain 3rd world region or under developed regions sometimes.

Nigeria is now something like world's no 1 fraud country. Lots of drugs problem too and in fact many Nigerian drug dealers got caught in my country.
Many countries in Africa are viewed with suspicion, that's quite normal given the actual condition of the many poor & unstable countries in Africa plus whatever crooked deeds many of the commit internationally. So Africa is a "doubtful" region overall for people who doesn't really know well of the continent. Probaby South Africa is the only place/country which is not too bad. I don't know African geography all that well too, sorry.

Where you are based now, I understand why the need of diplomatic package, it is tax free and less hassle by custom. To 1st world country people, it may seem like a questionable method of import.

As far as fraud, even Indonesian credit card is getting unacceptable in many on line shops world wide. Romania ranks 1 fraud fro credit card in the world , and a few other african countries in the list. There are even some on line retailers that will highlight : "CREDIT CARD FROM XXXX COUNTRIES NOT ACCEPTED "

Honestly speaking even I get my card busted by some Indonesian crooks last year.

You go to any Asian airport in the world, anytime any African nationality comes over to the immigration desk, it will be tons of questions by authority and requiring the proof of return tickets, enough cash and so on. This is a fact.

Neil is a very helpful person and this forum is a wealth of knowledge. It will be waste if you guys ended up arguing. In fact Neil assisted me a great deal in my calculation and offered a few operational scenario which I did not know could happen.

So I hope you can understand why all the suspicion.

Peace & Regards to all,
IYA

nigtomdaw · August 2007

Re: Charge controller problems in Africa

Try importing IMHO an in-expensive and bulletproof Xantrex C35 or C40 ( or a comparable quality MorningStar Product ) they all come with a comprehensive manual and easy useable selector pots and jumper switches.....get the imput voltages sorted with your quality DMM so easy ,,and hey presto your charging safely again ! A Xantrex C35 is less than $100 on Ebay probably cheaper on line somewhere in the US and will easily cope with your biggest individual proposed on site load,.....So start with a known proven good value for money quality Solar Charger product then armed with .....a DMM in one hand a little bit of ohms law and V=IR in the other and Im sure you will sort it....... no poblem as a five year journey man electrician.

See not a crossed word !......yet...such a long journey......phew.................. but..... I can,t understand your statement (mostly code based wiring without much theory) if code based wiring is then practical without much theory then spot the sizzingly almost glow in the dark crispy barb b que sparky ,,,, I dont like being callled a >>>>> your credentials just dont stack up to me RIM .............Im so so sorry !

You seem very liberal and quick to dish out the verbal abuse.... try putting a much bigger fuse in your system it goes just below your nose..it really helps with surges of aggression (current) with out blowing your trip ! Safety after all is important in all instalations which is paramount even with dodgy capacitors ........right !

Love the forum .... a retired british police officer with O and A levels in Maths and Physcis and some other stuff and also a degree in common sense and an ability to learn from ones Peers with maybe a little scarcasim but without s...ging anyone off !!!

System2 · August 2007

Re: Charge controller problems in Africa

OK guys, a journeyman electrician is NOT a master electrician, is NOT an electrical engineer and is NOT an electronics technician. We are highly skillful in work quality and safety and following the NEC ("National Electric Code" for the international crowd) to the tee. Most journeyman that I know don't design systems from the ground up, we start with blueprints, figure out load calculations and start wiring away. The guys that have always done the designing for me have been electrical engineers. Most of my work has been with AC with only minor dabbling in small DC control wiring. Thus I have the skill to complete the work in a safe and skillful way, but my troubleshooting skills, in this case, are extremely limited. That was what I was hoping to get across when I stated my experience. I don't know what was lost in translation but I hope it is all understood now.

Speaking of translations, can someone please translate the following into American English for me?

nigtomdaw wrote: »

See not a crossed word !......yet...such a long journey......phew.................. but..... I can,t understand your statement (mostly code based wiring without much theory) if code based wiring is then practical without much theory then spot the sizzingly almost glow in the dark crispy barb b que sparky ,,,, I dont like being callled a >>>>> your credentials just dont stack up to me RIM .............Im so so sorry !

You seem very liberal and quick to dish out the verbal abuse.... try putting a much bigger fuse in your system it really helps with surges of aggression (current) with out blowing your trip ! Safety after all is important in all instalations which is paramount even with dodgy capacitors ........right !

Love the forum .... a retired british police officer with O and A levels in Maths and Physcis and some other stuff and also a degree in common sense and an ability to learn from ones Peers with maybe a little scarcasim but without s...ging anyone off !!!

Nigel....IMHO you are very hard to understand after the helpful first paragraph. Especially the bit about a sizzingly almost glow in the dark crispy barb b que sparky

I don't get what you are saying at all. Try reading what you type before you submit it along with having someone else look at it.

See, easy not to have a crossed word when I don't understand WTF you are saying.

System2 · August 2007

Re: Charge controller problems in Africa

RIMSolar wrote: »

Anyways, Niel, I accept your apology but if you look back, the whole first half of your reply was accusations and insults and not questions. I think you might have jumped the gun a little bit there. Maybe I did too in my reply and my apologies to you and your mother (accepted and please look back as you'll see question marks after 3 sentences. that mark does constitute a question and not a statement. added by niel)

YOU'RE A (edit by niel)!!!! (no more name calling so knock it off already. added by niel)

Niel just leave it be, you insulted me first and I insulted back, no biggie. The first half of your message without question marks was longer than the second half no matter how many punctuations there were.

And calling someone a freek is like calling someone green or blind ("in the dark") or a liar (insinuating they aren't who they say they are) which is what you called me. If you didn't want me to name call you shouldn't have started it. I don't think that any of these names has hurt anyone's feelings since the 5th grade anyways.

I'm ready to move on.....are you or are we going to keep going with this?

niel · August 2007

Re: Charge controller problems in Africa

it would appear that you don't have as big of a renewable energy problem as you first indicated for you are focussing on myself and another member and not the problem you say you have. if you wish to address your re problem with others please do, but if you are not going to do this there will be repercussions. get back to the subject or there will be no more subject, your choice. final warning!

Charge controller problems in Africa

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