September 14, 20169 yr 1 hour ago, Daniel128 said: What is the best way to connect the 2 battery banks some sites say +- +- +- +- to build a 48v bank and then they say to connect the one banks + and - to the author and then then one cable to the inverter? What you need to ensure is that the cabling connecting the one string is equal in length to the cabling connecting the second string so that each string of batteries has the same resistance and that they charge evenly. Having uneven length of total cabling or mixing and matching battery types or chemistry (yes I have seen this) put paid to any hope of even charging. For two strings this is probably (after a busbar) the best setup. Notice the cables connect individual batteries are all equal in length and two bridging cables are slightly longer but they in turn are the same length. 42 minutes ago, The Terrible Triplett said: I would connect the 2 x 48v banks to busbars. The correct way of connecting multiple strings is with a busbar but for two string I feel that it is an overkill.
September 14, 20169 yr 1 minute ago, Chris Hobson said: The correct way of connecting multiple strings is with a busbar but for two string I feel that it is an overkill. No so sure, the costs are negligible for 2 busbars. Makes it easier long term and it just looks awesome. 34 minutes ago, plonkster said: This time that it spends on float... this is the most inefficient most wasteful part of the daily cycle... Why? Since I upgrade both my controllers, 2 systems, I can see them both sitting on float after about 2ish, the rest of the afternoon, whilst the loads are powered.
September 14, 20169 yr Author 12 minutes ago, Chris Hobson said: What you need to ensure is that the cabling connecting the one string is equal in length to the cabling connecting the second string so that each string of batteries has the same resistance and that they charge evenly. Havign uneven length of total cabling or mixing and matching battery types or chemistry (yes I have seen this) put paid to any hope of even charging. For two strings this is probably (after a busbar) the best setup. Notice the cables connect individual batteries are all equal in length and two bridging cables are slightly longer but they in turn are the same length. The correct way of connecting multiple strings is with a busbar but for two string I feel that it is an overkill. Thank you for the help Chris So I must use this battery connection setup with 12v to give me 48v in 2 banks. Can anyone advise me what will be my volt and ah figure when connected together im not sure what the correct formula is to work it out.
September 14, 20169 yr Jip so you have 4 battery connected in series.(Amp hours stay the same and voltage is added so 12V + 12V + 12V + 12V = 48V and 170 Ah). These series connected batteries are in effect one big battery. Now you connect two strings in parallel (Amp hours is added and voltage stays the same ( 170Ah + 170 Ah = 340 Ah at 48 V).
September 14, 20169 yr Author 12 minutes ago, Chris Hobson said: Jip so you have 4 battery connected in series.(Amp hours stay the same and voltage is added so 12V + 12V + 12V + 12V = 48V and 170 Ah). These series connected batteries are in effect one big battery. Now you connect two strings in parallel (Amp hours is added and voltage stays the same ( 170Ah + 170 Ah = 340 Ah at 48 V). thank you for that it makes much more sence now.
September 14, 20169 yr 40 minutes ago, The Terrible Triplett said: Why? Since I upgrade both my controllers, 2 systems, I can see them both sitting on float after about 2ish, the rest of the afternoon, whilst the loads are powered. Okay, so if your setup is anything like mine, in the mornings you have all the loads powered and the batteries are also charging (bulk, then absorb mode). Then around 2PM it goes to float. Now unless you do something to increase your loads and use that power, your actual PV harvest comes down (because less needs to go into the batteries, and the loads are the same as this morning). All that power that's now choked away because the batteries want less... that's the inefficient bit I'm talking about. Additionally, where a battery below 90% of charge is quite efficient in accepting and storing charge, once you go above 85% SoC the battery accepts less charge and as much as 40% of the energy you DO push in there is lost (coulomb losses, gassing, etc). That makes it even worse. So on a typical afternoon, while I might have 700W or more available (which is roughly what happens), I end up using less than half of it (80W to float the batteries, 200W for the loads) and of the 80W going to the batteries only about 50 is actually absorbed... So basically, this is why I want to get the full Hybrid (aka hub-4) setup going. Then I can run the dishwasher after lunch, time the electric geyser for later in the day, stuff like that. :-)
September 14, 20169 yr Aaaa, with you. The 930w panels, minus losses and all that, I happily power 550-700 all day, depending on what is on. Lights and fridge all night too. Since I upgraded, panels are now in series, I also get above 1000w from the panels on cool days. But due to evening loads, in the mornings I have to wait for the BMV SOC to reach the clear relay setting, and that is annoying me now. Yes it is good in summer but winter is where the tjunning is required. So last step for me is to change over faster in the mornings, automatically, when the batts are still on wot, 80%-85% DOD, that the system can work them panels harder for longer.
September 14, 20169 yr Author 16 minutes ago, The Terrible Triplett said: Aaaa, with you. The 930w panels, minus losses and all that, I happily power 550-700 all day, depending on what is on. Lights and fridge all night too. Since I upgraded, panels are now in series, I also get above 1000w from the panels on cool days. But due to evening loads, in the mornings I have to wait for the BMV SOC to reach the clear relay setting, and that is annoying me now. Yes it is good in summer but winter is where the tjunning is required. So last step for me is to change over faster in the mornings, automatically, when the batts are still on wot, 80%-85% DOD, that the system can work them panels harder for longer. My 9 panels are also connected in series 3x rows of 3x panels each one panel is 230wp so what rating are they 29.1 v and 8amp is the 230wp the watt rating? How many more panel’s can I add on my current inverter? I see the previous person who installed them connected all rows with connecter blocks to one main 3 core wire. What will be the correct way and with what type of wire and connectors must I replace them with?
September 14, 20169 yr Author 3 minutes ago, Daniel128 said: My 9 panels are also connected in series 3x rows of 3x panels each one panel is 230wp so what rating are they 29.1 v and 8amp is the 230wp the watt rating? How many more panel’s can I add on my current inverter? I see the previous person who installed them connected all rows with connecter blocks to one main 3 core wire. What will be the correct way and with what type of wire and connectors must I replace them with?
September 14, 20169 yr Author Like I have mentioned before I have 2 micro care mptt units and 3 small solar panel’s TE95-36M What do you guys suggest I do sell them for funds or keep them???
September 14, 20169 yr Author 5 minutes ago, Mark said: Can you post spec's for the smaller panels... size make etc. Regards Mark
September 14, 20169 yr 2 hours ago, plonkster said: Then around 2PM it goes to float. @Daniel128 this is what we are talking about. Batteries takes a while to get to 100%, but I am not wasting power, controller balances it all that the load is powered, yet batteries are on float. Must say, respect for the engineers who made this possible.
September 14, 20169 yr Hi so a very helpful friend told me to connect two banks as in diagram to push power through all battery. Going to try on weekend. Cable length will be equal lengths diagram is just example
September 14, 20169 yr Okay, time to answer your questions. On the back of the panel, it says Open Circuit Voltage is 36.8V for the one and 22.4V for the other. Lets make that 37 and 23 to make the math easy. Those MicroCare Controllers have a Voc rating of 150V. So you can put panels in series as long as you remain under 150V total. 4 Panels in series will put you a bit too close to 150V (148V), so three panels in series (of the larger type) is what you can do. With the 12V panels (those with the 22.4V Voc), you can series up to 6. But... without getting too technical. An MPPT is a buck converter, and they usually have design constraints where they work best, the inductor, capacitor and frequency used by the converter is chosen to fit such a range. It's best to stay within a voltage that is between 2 and 3 times the battery voltage. With a 48V bank, that means aim for 100V to about 135V (just to leave enough space at the top). I would keep the panels and controllers. The MC units are good.... not top of the range, but a great deal better than anything else made in this country or in China.
September 14, 20169 yr 4 hours ago, Daniel128 said: I see the previous person who installed them connected all rows with connecter blocks to one main 3 core wire. This is allowed as long as 1) the wire going down can handle the current, 2) the wire used is proper solar cable that can handle UV and other weather conditions, 3) you have fuses between the strings (each set of 3) where it connects to the common wire. This means fuses on the roof, which generally means water right fuse boxes and stuff like that, and getting onto the roof whenever you need to work on it. It's therefore better to rather use a cable for each string and combine them below. I have a setup myself where I parallel them on the roof: But my panels are on a flat roof and easy to reach: It's an acceptable compromise. 3-core wire? For AC? Rip it out immediately and put in the right stuff. I must say this is an odd setup. Those Microcare controllers aren't cheap. I mean, they are cheaper than Victron or Outback, but a 40A unit is around 5.5k (iirc), so you have around 15k worth in charge controllers there, combined with a cheap inverter and a botch job in the cabling... maybe the previous owner got the controllers for dirt cheap somewhere... because given the rest of the setup I'd have expected something cheap....
September 15, 20169 yr Author Good morning everyone I just want to thank all of you for the over whelming help and advice I really appreciate it. Hopefully one day soon I can do the same and pay it forward with the ability to help someone else like you all are helping me. I have made some changes to the system last night and its looking good and im feeling more confident that the system will start running more reliable and im off to a good start to make it more safer and comply with the set safety specifications to get an coc for it soon. Ill post new pictures soon.
September 15, 20169 yr Author As promised here are the updated photo showing some of the changes in the battery bank. Long way to go still trunking for the wiring more safety fuses and I want to re build the db box but it’s a start.
September 15, 20169 yr Hi Daniel From the photo it looks like the bridge cables connecting the individual batteries are not even in length. Just check. Chris
September 15, 20169 yr Author Just wanted to ask if anyone knows what this (HS) symbol mean in the centre of the display? Since I did the re wiring of the battery banks and reset the inverter this symbol is gone. I have gone through the manual I have for the inverter but is dussent specify anything about this symbol.
September 15, 20169 yr Symbol "HS" is in fact "MS" and stands for master in parallel connection, when you have two or more inverters connecting together.
September 15, 20169 yr Author I also have noticed a change in my settin menu no 28 was PAL now it shows 51G can anyone advise me on this? I know this is the setting if you run a parallel inverters and im not so possibly I don’t even have to worry about it just curious
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