gpigeon

Further to this battery mystery!!!!!! As stated earlier, I replaced the dead 2RPG1410 cell with a 10EPzV800 because the 2RPG' are no longer available. Exide, the battery supplier tried to recover the failed cell but told me it was unrecoverable. They offered to pay me scrap value but for some reason I decided to bring it back home. So, I connected the dead cell in parallel with the new 10EPzV800 cell only using 2.5mm2 cable. After a few months I noticed that the dead cell was now holding it's voltage! Then, a second 2RPG1410 cell failed and I replaced it with the first failed one (the one that had recovered) and the whole system has been working perfectly for the last 9 months. I have placed the second failed cell in parallel now to see if it also recovers. What do our learned crew think of all this? off topic, but......how are things going over there in good old RSA? I went there for 2 weeks in 1972 and stayed for 7 years! I even brought one of your Boer meisies back home with me and we have just celebrated our 40th wedding anniversary. Mind you, she still gives me a hard time!!!!!

Interesting numbers "Hawki"...... Looks like from your figures that power in SA costs about R2.66/kWh. I am on the East coast of OZ and my house is totally off grid but i have a shed that is grid connect but has 10kW of panels on it. We pay A$0.30 per kWh (plus $1.40 per day access fee) for power supplied and get back A$0.17 per kWh for power exported to the grid. The current exchange rate is about R11 = A$1, so say that works out to about 24c per kWh that you pay. Not much difference!!! What is even more interesting is that when I left RSA (I worked in JHB and Durban for about 7 yrs) in 1979 the exchange rate was about 1 for 1. However I would not think that your standard of living has changed very much over that period????

Thank you Plonkster for this info. I also had a "dead" BMV702 after 4 yrs operation. I checked for Voltage at the end of the cable as per your directions and all was good there so I have ordered another BMV702 at a cost of $200. I hope this one lasts longer than 4 yrs!!!! All you guys in the good old RSA take care. According to the TV news things are a little tough there atm. i went there for a 2 week holiday in 1972 and stayed 7 yrs. Very fond memories of Hillbrow and surrounds. All the best to you.

Coulomb....I understand and agree with your reasoning, but it not as bad as you state. For some crazy reason, perhaps just to confuse us mere mortals, the 2RPG1410 cell is 1410Ah @ c/100 rating whereas the 10EPzV800 is 800Ah @ C/5 rating! The 2RPG1410 is actually only 1000Ah @ C/5 rating. So, I am losing only 20% of my capacity. Yes, still not good I know. Considering that the highest discharge I have seen in 4 yrs of operation is 196Ah (that was just the other day after 2 consecutive days of very heavy cloud) the 800Ah cell would have only been discharged to say 200/800 = 75% DOD. Normally the batteries are fully charged by10am even on a cloudy day. (10kW panels) Anyway, I will stick with what I have for the moment and keep an eye on things. Cheers.

Ok, latest update.... The dead 2RPG1410 cell is unrecoverable!!!!! No interest in a warranty claim because Exide say that the cell was never charged and equalised according to their specs. As stated earlier, the Schneider charger I have been sold is not capable of charging to their specs. in any case!!!! When are we going to get some experts in this solar industry? At the very least, one would expect that Schneider and Exide/Sonnenschein could talk to each other and develop compatible elements!!!! So, Exide have provided me, at 20% discount, one 10EPzV800 replacement cell. I picked it up yesterday and hope to have it up and running tomorrow. My question to you guys is....what do you think of mating up different types/ratings of cells ? ie 23x 1410Ah cells and 1x 800Ah cell.

Ok, so the inevitable has occurred.....I have had one cell fail totally. It charges up just fine during the day but drops to zero V overnight. After speaking to the battery supplier, I removed the faulty cell and changed all the charger settings to suit a "46V" battery. So far everything is going ok but naturally with 4% less capacity. The warranty was only 5 yrs and I have had the system for 4 yrs so they are not too interested in a claim. In any case the battery has NEVER been equalized so they will most likely use that as an excuse as well. However, they have agreed to test the cell and try to "rejuvenate" it so I dropped it off with them last Friday. I was up your way "Coulomb" in Acacia Ridge at GNB/ Exide. Too many people in Brisbane for me...I was pleased to get back home to the bush!!!! To make matters worse, that particular type/brand of battery is no longer made so I cannot simply replace the faulty one with a new one...apparently not a good idea anyway. It will be interesting to see how this rejuvenation process does??? Ideas, suggestions, comments????

So, why does the battery manufacturer state (see prev. att) that equalizing is necessary???

"phil.g00", thanks for your reply. Reading up on things is doing my head in!!!! You + many others incl. Schneider say "Do not equalize gel batteries"!!!! See Att Sonnenschein data sheet which clearly states that they should be equalized! However, they will not recommend a charger to do it! I now have one cell out of the 24 that drops to zero V (thus, I am getting a high "mid pt dev.%" alarm on my BMV702) when the battery V drops below around 48V. However, after charging that cell is fine. I'm thinking that if equalizing can not be carried then perhaps balancing can be??? Please point me in the right direction if you think I should read up more....for the last week I have been doing a lot of reading!!!! Thanks. Bill. energystore_gel_EPzV_instructions.pdf

I have 24x Sonnenschein Energystore 2RPG1410 Gel cells which are charged via 2x Schneider 80 - 600 controllers and/or a Schneider XW+8548 Inverter. The battery suppliers state that the cells should be equalized whereas Schneider say that Gel batteries should not be! I am the man in the middle!! Any of our forum members with Gel cells? As I have recently seen 2 high "mid point V dev%" alarms recently on my Victron BMV702 I am a little concerned. The installation is only 4 yrs old and has been trouble free up till now. I log individual cell voltages regularly (se att) and no one cell is ever high or low. Another possibility is to use a battery balancer (say an HA02)on the highest and lowest average cells. Any thoughts??? Thanks. Bill. battery log.xls

Thanks for your replies gents. I tried both the 68k & 135k resistors....both work ok and I cannot see any difference in brightness of the LED. Did not use a cap.or diode! Why do I need these? I underrstand the reverse polarity of the AC supply but it seems to work ok without them. Comments????

I have in the past driven a normal LED form 240VAC by using a resistor. Now I cannot find exactly what resistor value I used. However, one of my ref books gives the formula R=(Vsource - Vled)/Iled Does this formula work for 240VAC? Will a flashing LED work on 240VAC as well? If someone has an online reference to this subject I would appreciate a link. Thanks & "Dankie".

Hi Mark and thanks to others for the replies. Interesting! I also have a 3ph farm connection but use very little power. Say about only 5 kWh/mth. However, I forgot to mention in my original post that there is also a "service" fee of R14.50/day. Still, I do ok out of it because I export about 1000kWh/mth so after all costs come out the utility deposits about R1500/mth into my bank a/c.

How much in round figures do you folk pay (per kWh) for your grid supplied power in SA? Here in Oz we pay around A$0.30 (say R3) per kWh but with Federal elections just around the corner, the Gov't. says they will reduce this by 25%. Unlike with Eskom (I think??) our utilities are all now privately owned. Used to be Gov't. owned in the old days! We also get a Feed in Tariff of around A$0.20 for each kWh we feed back into the grid so that could well be affected if supply charges are forced down.

The pricing of the Evac. tube systems in RSA is very interesting. Seems like you guys can get a 200L system supplied & installed for around R20k. That is only about A$2000. I had a new 200L system installed about 2 yrs ago on the East coast of Oz. and it cost me about A$4500(supply only), that is around R45k. Why the big difference??? Strangely, when I lived in SA in the 1970's the exchange rate was about the same.ie R1 = A$1. Given that now R10 = A$, I would have thought that the R had "devalued" but in fact some of your goods are much cheaper??? Hey "d3nominator"....I used to live in Alberton. How is it going these days?

Thanks for the reply "Silver...." I had a look at that link but I think the scheme I am referring to was long before that. Say Late 1970's. Also, that Wiki link does not mention "pumped hydro" but maybe my poor old brain is a little confused....not difficult to do these days! Pumped Hydro is having trouble getting support even in Oz because it is a massive long term project and no Gov't. will start something that it's successor may get the benefit of. From what I see on this forum about the state of the power system in RSA these days a big project would have even more difficulty getting off the ground over there???? See this...interesting? https://www.abc.net.au/news/2019-01-30/snowy-hydro/10683112

About 40 yrs ago a Civil Eng. friend of mine was working on a "pumped hydo" scheme somewhere just south of Durban. I have lost contact with that friend but I was wondering if that scheme ever got up and running and if so what were the results. There is a lot of talk atm about pumped hydro in Oz but to date I don't think much has happened. It does seem like a good way of storing offpeak PV or wind power for use during peak times. Like in RSA, we are short of water at times but surely with a pumped system there would not be a lot of wastage as the water could just be recirculated. Even salt water??? Thoughts/comments??? Cheers. Bill.

Hi "TT", More details please! I have a BMV702 installed so I guess you are referring to the "relay" function in that unit?? I have been toying with the idea of using that relay to switch on/off a small home built HWS (geyser in SA taal). I have an evac tube heater but after a day or two of cloudy weather I have to turn on the inst. LPG water heater. Whereas the 1410AH batteries are already fully charged by midday, even on cloudy days, so I could be using the excess PV power to heat water???? Thoughts?

Hi Chris....thanks for the reply. I did change the tail current seeting to 2.8% and yes, it made the SOC reading more accurate. In the overall scheme of things it doesn't really change the performance of the system. It just makes the SOC reading on the 702 a little more in line with the SOC shown on the XW8548. Cheers for now. Take care & all the best for 2019.

Many thanks to those that replied. I think I now have the general picture..... Just as a rough comparison....given that A$1 = 1R (don't know what happened????I think when I was there they were roughly the same!!!) The domesic power price here in NSW is around 30c/kWh and I get paid 20c/kWh for every kWh I feed back to the grid. Connection fee is around $1.40 per day. The feed in tariff was originally 66c/kWh so since installation in 2010 my 10kW system has returned around A$58,000 but of course the purhase price was a lot higher then. (about A$45k) It will be interesting to see how FIT's go in the future as more and more peoiple install solar PV's.

No replies???? Very srange! I must be asking the wrong questions. Surely I haven't offended the forum members after only 3 posts???

It is a long time since I was in SA....I went there for a 2 week holiday in 1972 and stayed for 7 years.I still have many great memories of my times there around Hillbrow!!! Just a few general questions re electrical power in SA.... Does SA have feed in tariffs? (ie payment for power fed back to the grid) If so, how much per kWh? Cost of power purchased from the grid? Is Eskom still the only supplier of power?

Mornin' Jaco, Thank you for the prompt and informative reply. I think that this solves one of my other queries I had with the BMV702...it was showing 100% charged whilst the XV8548 had only 3 or 4 of the five LED's lit. Five is fully charged!!! That meant that the BMV702 was indicating full charge too early. Not that it mattered all that much in the overall scheme of things. I will monitor the system and see exactly what has changed now that I have reduced the setting from 10% to 4%. Cheers. You have a good day.

This is my first post on this forum. I am impressed by the overall content of the forum generally. I have asked this same question on our local solar forum but did not get a reply so I will try here as I see that the Victron BMV702 gets quite a few mentions. My basic setup is : Schneider XW8548+ inverter. Schneider 80/600 charge cont. x 2 Sonnenschein 2RPG1410 batteries x24. My question....what is the "tail current" mentioned in the Victron manual? I see from other posts that the default is 4% but some say that should be reduced to say 2.8%. Mine was 10% (not sure how it got to that) and I reset it yesterday to 4%. I can't really see that it would have any influence on the charging regime in my case because the BMV702 does not interact with the charge controller in any way. The BMV is merely a "fuel gauge"???/Correct? Merry Christmas to all of you. Cheers.