10 hours ago, Wingman said:

PLEASE  HELP

 I need to know:

1. ·        Point Back Voltage (drop batteries and back to utility/Eskom)
2. ·         Bulk Charging Voltage:
3. ·         Floating Charge Voltage:
4. ·         Low DC Cut-Off Voltage:
5. ·         Max Charging Current: Solar
6. ·         Max Charging Current: ESKOM/utility
7. ·         Max Charging Current: Solar + ESKOM

PLEASE will some of you electrical wizards come to my rescue and “save the day”? Thanking you in advance.

Hi Wingman

Welcome. I hope I can give you your piece of mind I was busy typing when you asked for my help (again). Don't panic I am not the only one who knows these inverters well.

1. 48V as a start. The problem with using voltage for switching is that load influences voltage. 48V is roughly 50% DOD. If you have heavy loads you may have to lower this as a heavy load lowers voltage more than a lower steady load. After the draw from a heavy load ceases battery voltage can actually recover.
2. Bulk 58.8V as you have been advised (2.45 V per cell).
3. Float 54.5V Determined from your datasheet (2.27 V per cell)
4. Leave it at 42V otherwise you scramble the Axpert's calculations. Purchase a BMV 702 to protect your batteries.
5. Max Charging current (Program 2) set to 20A. This if for solar and solar/ESKOM.
6. MAX AC (Program 11) set to 20A.
7. Determined by Program 2 so you do not have to set this separately.

 

I think others have alluded to this but your batteries are not really suited to a solar application.

So what my recommendation is that you use solar during the day and work off grid at night, saving your batteries for when the power is off. This can be achieved by setting Program 1 to SOL and Program 16 CSO. This is a very poor way of controlling the inverter and perhaps a geyser timer on your inverter will help or getting software like Jaco's AICC or TTT and Ed's SolWeb.

If you are worried about cooking your batteries you can reduce the bulk charging rate to 58V in summer (>20^oC) since the bulk charging rate is above gassing voltage.

Chat to @Camel about a BMV or ExSolar in S West is a Victron agency. @Mike an installer in Yzerfontein may have some tips and be prepared to give your system the once over. I will be in CT in Nov and if at that time you still not sure I can pop round.

 

 

47 minutes ago, Jaco de Jongh said:

the only way to know the condition of your batteries is by using a battery monitor

Well I won't say that is the only way. There are other ways, makeshift ways. On my fancy Victron charge controller there is a nice stat I can access via the LCD that tells me how much time was spent on float today. When I come in in the afternoon, if that indicates that we spent at least 3 hours on float today, I know we're full.

33 minutes ago, Chris Hobson said:

ExSolar in S West is a Victron agency

They sell Victron stuff yes, but also a lot of other stuff. There is also Ontrack literally just around the corner from ExSolar (at "The Interchange" in Somerset West). ExSolar has it on the shelf though. If it was me, I'd just order it from Sonopsolar and have it shipped to my door :-)

And speaking of The Interchange, the street name that runs through it is called Dynagel street, pronounced "Dyna" as in dynamic, and "Gel" as in Jelly. Its a kind of explosive. It's not Dey-Nah-chul as the 4x4 Megaworld ad on the radio says it :-)

To all you guys out there that answered my call for help, PLEASE accept my sincere gratitude. This week I will reinstall the batteries and set the Inverter as suggested by you guys. Also, thank you all for not only suggesting I get a battery monitor but also for telling what type and thus saving me another headache. Kind regards. Bernard Vreulink

Hey Jaco,

Glad you happy with your 702 

Yes you can't go wrong with a BMW 702. I have about 20 odd happy customers on here.

Wingman, Ask Camel for a BMV price and delivery. He is the BMV supplier here.

A point I want to lift out, rest covered the inverter settings, them Excis batteries, I know them well.

They are perfect for UPS'es, and also not, but not really for use in a solar system unless they are only used if and when there are power failures as Chris suggested.

I lift these little titbits from the link you sent:
EXCIS FMF102 Battery Standby Applications.
Not to be discharge more than 80% - like in there is no power and you need to run things urgently once in a while.
Or cycles more than 50% of its nominal capacity - this is for daily cycling.
Carries a limited 12 months pro-rata or 250 cycle warranty - and that is the bummer, you maybe get 250-350 cycles if you use them every day.

 

EDIT: Unless you have a BMV and never let them go below 10% DOD.
The graph provided says 2000 cycles at 10% DOD.
20% is 1400 cycles.

Try and stay in that DOD and get the max value back from the batteries.

1 hour ago, The Terrible Triplett said:

EDIT: Unless you have a BMV and never let them go below 10% DOD.

Was just about to say that. Look at the cycle life chart. A 10% DoD won't shorten their life much more than just floating them all the time. So just cycle them 10% then and do self-consumption during the day :-)

Your system is very similar to mine except that I went for 8 x 6 V 225AH Trojan T105 batteries and 2 x Inverters in parallel with the total house load connected to the inverter output. The MPPT operating range of the inverter is 60 to 115 VDC. So if the maximum voltage of your panels is 37 V under load, a set of three will give 111VDV, still below the specified maximum. However a set of 2 panels only produces 74 VDC and that is maximum. It would seem that 2 sets of 3 panels each may be a better bet. The bulk charge voltage of my T105's is 59.3 V but the maximum of the inverter is 58.4V so that is what I set it at. Switch back to grid is set to 44V but only to ensure that I don't discharge below somewhere around 50% in case of Eskom going belly up again.

The Inverter is controlled by AICC which I really like. It makes it easy to control the inverter from my computer. On AICC I set Switch to Solar at 100% and Switch to Grid at 80%. Hopefully I will get the maximum battery life with these settings. Also the inverter is set to charge the batteries only from solar (Setting 16 is set to OSO). Hope all this helps and does not confuse you even more. There are also some additional settings on the inverter that has to be set appropriately for AICC to work as expected.

Thank you once again for all you clever guys out there that answered my desperate call for help. With the mass of info I received from so many forum members I have NOW programmed my RCT - AXPERT 5K Inverter as follows and kindly request any advice/correction should I have misinterpreted some of the well-meaning info. The info I really wish to be confirmed/completed is in BOLD.

I have 8 (2 X 4 in series) 100Ah lead acid batteries providing 48V

6 (3x2 in series) 310W Solar panels – Voc = 42.1V

(The whole idea behind my system is to have "back-up" for the deep-freeze and lights when Eskom stops and not so much to go completely off-grid. I have a very efficient solar water heater and so NO large current is demanded except for a 1000W microwave oven.) 

Inverter settings are as follows:

1 – SOL (Output source priority)

2 – 20A (Max Charging Current)

3 – UPS (AC Input Volt Range)

4 – SdS (Power Saving Mode)

5 – USE (Batt Type)

6 - LⱵd (Auto Restart)

7 -

There is no 8

9 – 50Hz

There is no 10

11 – 20A (Max Eskom Charging)

12 – 46V (Volt POINT BACK to Eskom)

13 – ???? (Volt POINT BACK to battery when SBU or SOL in program 1) PLEASE

There is no 14

There is no 15

16 – OSO (Charging source priority)

There is no 17

18 – b0N  (Alarm)

19 - ⱵEP (Auto return to default display)

20 – LON (Back Light)

There is no 21

22 – AON (Beeps while primary source is interrupted)

23 – bYE (Overload Bypass)

There is no 24

25 – FEN (Record fault Code)

26 – 58.0V (summer) and 58.8 (winter) (BULK CHARGING VOLTS)

27 – 54.0V (FLOATING CHARGE)

There is no 28

29 – ????? (Low DC Cut-Off Voltage) PLEASE

There is no 30 

31 – SbE (Solar Power Balance)

 Thanking you ALL once again, cause I was close to "cutting my wrists".

 

 

 

I prefer using the solar panels but I thought it prudent to select ALL the correct settings on the INVERTER so that I can't get caught out during something "unforeseen".

26 minutes ago, Wingman said:

I prefer using the solar panels but I thought it prudent to select ALL the correct settings on the INVERTER so that I can't get caught out during something "unforeseen".

Following on from TinkerBoy's question, and your answer, you have solar panels, always use them to charge batteries.

If after a week of bad weather they just never get fully charged, then you can top them up with Eskom, that is what I would do.

Hi TinkerBoy. Thanks for suggestions. During sunshine hours I charge the Batteries and use only solar. When the sun sets I use Eskom so as to "save" the batteries for when there is NO Eskom. Am I dong the right thing? By the way, you suggest I set ESKOM to 2 Amps ....... are you talking about setting "11" where I have 20 Amps? Keenly awaiting your or anyone else's reply.

WOW ..... thanks ...... almost every forum member teaches me something NEW. What is a AICC please? What program on my INVERTER do I set the 2AMP ESKOM "FLOAT" charging or does the AICC do that? If you have the time, please explain in very simple language. THANKS!

 

 

Please tell me what is a AICC and where do I buy one? THANKS!

31 minutes ago, Wingman said:

WOW ..... thanks ...... almost every forum member teaches me something NEW. What is a AICC please? What program on my INVERTER do I set the 2AMP ESKOM "FLOAT" charging or does the AICC do that? If you have the time, please explain in very simple language. THANKS!

Hi Wingman

Option 2 works like this.
Maximum charging current = utility charging current (option 11) + solar charging current.
So setting option 2 to 20A and 11 to 2A should do the trick.

Option 16 should be on CSO for utility to be able to float the bank when on bypass mode

A link to AICC
http://aicc.org.za/

Thank you for your reply. I have almost no idea what you are talking about ..... only understand from what you write that AICC is a computer program and that you still have an old Windows version. My PC is not connected to my INVERTER. Is there something else I can get/buy. I am advised to get a battery monitor. Is AICC a battery monitor? SORRY, but I am COMPLETLY out of my depth and in the DARK.  ;-(

Thanks "TinkerBoy" for your explanation. I am grateful the FORUM has not kicked me out yet cause I keep on asking questions you FORUM members has most probably already forget the answers to cause you guys are SO FAR ahead.  ;-) 

Wingman go to the AICC.org link that Tinkerboy gave you 2 posts up. Download the software and extract it in a folder on your Windows PC. Also look at all the Youtube training videos on the website to learn hoe the software works. You also need;

1.x Victron BMV700 or BMV702 Battery Monitor. The BMV702 is more expensive and can do a few more things.

1 x Victron USB Converter cable for the BMV

I got mine from Exsolar on the Internet at a cost of some R4500.

You also need the following to connect to your PC,

1 x Serial to USB Converter

1 x USB Powered hub with at least 2 input and one output port

1 x USB Extender Kit if your PC is more than 2 meters or so away from the inverter.

Connect the serial port of the inverter via the serial to USB converter to a USB hub input port using the supplied serial cable.  Connect the BMV with the Victron USB cable to another input port of the USB hub. Connect your PC to the USB output port via the USB extender with a suitable thin Ethernet cable (RJ45). Start AICC on the PC and set the settings as required. The Youtube videos on the AICC website will guide you.

Good luck. My AICC works like a charm and I am eagerly awaiting the release of the Rasberry Pi version.

 

Thanks ebrsa for the effort you made to educate me. The AICC thing appears to be way above my abilities cause I am "old school" and still live in the "spanners and coal" era and not PCs and software. Does the BMV702 simply connect to the batteries so I can see whats what with the batteries and manually stop charging or keep on charging? Is the BMV702 a device that I connect to the battery bank? If I don't have to get al tied-up with PCs and software I would prefer not to ...... "spanners and coal" remember. Is  Rasberry Pi  a thing/guage/tool or a software program? Please will you answer without losing "gedult"?   ;-)

@Wingman I hear you load and clear. I see where this is going. I like it a LOT. 

Where are you based?

Why I ask is that maybe you can go and visit someone let them explain and show you what is what, why when and how or maybe they can come to you.

EDIT: Forum is GREAT to share knowledge, but lets get you on a level that you know what is what.

1 hour ago, Wingman said:

The AICC thing appears to be way above my abilities

Perhaps time to blow the blue horn again. So one of the reasons I bought the inverter I did is because of the programmable stack in it, you can literally load little pieces of firmware plugin to do new things, and it comes with some generic ones, for example a generic plugin that can be used to disconnect the grid and run off-grid. With this setup you can wire the BMV's relay connection directly to an analog input on the inverter, and then tell the inverter to go off-grid when the BMV tells it to.

Because the Axpert cannot do this, tinkerboy wrote AICC long ago to bridge that gap. It reads the BMV and then instructs the inverter to do the right thing, using the comms protocol of that inverter. It's just a piece of software running on windows with cable connections to both the inverter and the BMV, click click here and there, and then it works as well as the Victron (as long as windows don't crash... but for the price difference I suppose you can live with that :-P ).

Wingman I guess TTT made a good suggestion for you. However it is not all as complex as it looks. Just look at the AICC instruction videos more often than once. There is no danger of overcharging the batteries once the inverter is set up as has been suggested by others before on this forum. Also I don't see any need for the BMV700 or BMV702 if you are not going to use AICC.

The Raspberry Pi is a credit card size computer and you can read all about it at www.raspberrypi.org. If you don't want to use AICC on your windows computer, wait until AICC for Raspberry Pi is released and after some studying, consider your options. You can also see video demos of this on posts by Tinkerboy on this forum. I found all I needed on the Internet and also with the help of forum members as well as on TinkerCity forum. Google is your friend here.

1 hour ago, ebrsa said:

Also I don't see any need for the BMV700 or BMV702 if you are not going to use AICC.

@ebrsa, this is not really true, there is ways to use the 702 in a "spanners and coal" way that proves to be very reliable. The 702 comes with its own contact as you know, the AICC is not developed for my Inverter yet, and still I am using the 702 to protect my batteries in conjunction with 1 internal setting to protect my batteries perfectly. I feel that statement of yours might mislead inexperienced guys on the forum into believing that if you don't have AICC that a 702 is a waste, and that is not at all true.

Wingman, if you are interested in a way to make the 702 work on your setup, I will be more that willing to send you a drawing of what you can do. I would also like some software to control my system,but its not available yet, so I did it the normal electrical way. Old relay Logic.

35 minutes ago, Jaco de Jongh said:

Old relay Logic.

+1 on that. The MOST reliable way.