diy solar

diy solar

MPP Solar, stop from utility charging?

Hi. As I have the same problem with a pair of powland 5kw units, and it’s very frustrating spending hours trying out combinations in the not so clear menus, I wondered if you found a solution? It’s mad to pay to charge batteries from the utility, defeats the whole plan. I got pathetic after sales service from powland, I wish I had bought better, but I’m stuck with these now,
if anyone can recommend a brand that actually works, and has decent aftersales, please let me know, we don’t get a lot of sunlight here in Donegal, so we want to use as much as we can! Regards to all.
Just unplug it.
 
How about disconnecting the utility input to charger permanently? Anyone tried it? I might give it a go rather than scrap these 2 new units. I asked the supplier for a diagram, but no surprise , no joy. They keep giving me pages from the user manual, ….
 
I just keep my grid switched off. If I need it due to a long storm, I will turn it on until thr batteries get charged. I do this even though Solar Only works on my MPP Inverters
 
How about disconnecting the utility input to charger permanently? Anyone tried it?

I do, most of the time. It's fine if you never need to pass through utility power. The issue here is being able to pass through utility power while also preventing utility power from charging the battery.

My utility input is switched. It's turned off most of the time but I can turn it on if for some reason I want the utility to charge the batteries. I don't use the pass through mode as my system is mostly for outage back up and running some off-grid appliances.
 
Well, I have a 5048 MGX and so far I seems ok for me. No utilty charing, if not neccessary... But it's still not under full load...

Check this out:

 
Well, I have a 5048 MGX and so far I seems ok for me. No utilty charing, if not neccessary... But it's still not under full load...

Check this out:

Hi , thanks for the update,
the powland seller to;d me that utility charging is needed so batteries are not left discharged for too long. As this will short the battery life. So, the setting OSO in menu, doesn’t actually stop utility power from charging batteries when in line mode. I have learned these line mode means when the unit is supplying utility power to load in bypass. None of this is clear in the user manuals.
I am looking at the MGX model now, I think it will support lithium, and that will take care of the discharged battery issue I think. At least the people at MPPSOLAR respond quickly, we just want the auto bypass to work, and we choose of batteries are charged or not.
let me know how yours works out, Regards Tony
 
Ok,
well still learning to unterstand the PIP but my understandig so far is:

1. If I select SBU - it will use solar / battery fist. If the requested power is not sufficiant it will switch to utility (Bypass). But not charging the battery using utiltiy. But if you request e.g. 1000W and solar is providing 500W, it will work in bypass mode (provide 1000W) and charge battery with 500W.
2. If the inverter is running in battery mode and no solar is available and it's reaches lower voltatge Limit set by step 12, the inverter will start charging using utility, until it reach stop voltage set by step 13. This is to protect the battery.
3. If you are above the voltage of step 12 and solar is available and no power is requestesed it will use solar only if set step 16 to OSO

I'm just thinking in this process you only can hit the low cut out voltage (step 29) if solar and utiltiy is not available ?

Right at the moment my setup ist not finished, a few cables are missing so I just power devices by using a extension cord. the SOC of my battery is right at the moment always at a level of 50-80%. so I can't tell what's happens when I reach my lower voltage levels.

Well the MGX Model does not have a real Lithium support, you still have to set a user battery profile -> it just support a few more bms system protocols.
 
On my LV6048 I have found no combination of settings that allow me to separate out the utility charging and utility bypass. When the utility function is active, you must bypass battery and use both the utility for loads and charging. PV can also charge the batteries at the same time while in utility (line) mode if it is available.
 
Thank you Gentlemen, it’s an expensive learning curve for sure. I think I will change over to lithium batteries, as they should be ok only getting PV charge when it’s available, and limit the load to the irrigation pumps only, forget the idea of using any excess power in the house. By running a very limited system, (max load 2000w for only a few hours a day in summer) I can forget about the utility back up , makes no sense to pay to charge batteries.
the ultimate solution is to have a huge PV array that never needs any utility back up, but that’s a big ask for Ireland
the 10kW of panels we have now can run the pump ok,. To run house as well prob needs 100k .
lifetime supply of d for generator would be cheaper !
 
So, any thoughts on lithium ? Recommended brands ? They are serious money, so serious research needs doing !
 
So, any thoughts on lithium ? Recommended brands ? They are serious money, so serious research needs doing !
We tend to build our own on this site, using Alibaba bought cells. Much cheaper. If you want to purchase commercial products, many like BattleBorn, Tesla, BYB, LG, Seplos, SOK, Pylontech, Weco, etc.
MPP inverters talk directly to Pylontech, Weco and Soltaro. Plan to spend at least 4-6x over a DIY battery.

As an example, My 26KW battery cost me $4500 to build. To buy a similar capacity Pylontech would be around $22000 US.
 
We tend to build our own on this site, using Alibaba bought cells. Much cheaper. If you want to purchase commercial products, many like BattleBorn, Tesla, BYB, LG, Seplos, SOK, Pylontech, Weco, etc.
MPP inverters talk directly to Pylontech, Weco and Soltaro. Plan to spend at least 4-6x over a DIY battery.

As an example, My 26KW battery cost me $4500 to build. To buy a similar capacity Pylontech would be around $22000 US.
Hi Sanwizard, thats very interesting, any chance of you posting up a few more details on those diy? I have an idea it won’t be only me that’s interested. Right now I have 32 x 130ah lead acid, and very disappointed with them. I am thinking of selling them on cheaply as leisure batteries to camper / boat users, and going over to lithium, for example, do you have any advice on using BMS ? any info greatly appreciated, regards from Ireland.
 
Hi Sanwizard, thats very interesting, any chance of you posting up a few more details on those diy? I have an idea it won’t be only me that’s interested. Right now I have 32 x 130ah lead acid, and very disappointed with them. I am thinking of selling them on cheaply as leisure batteries to camper / boat users, and going over to lithium, for example, do you have any advice on using BMS ? any info greatly appreciated, regards from Ireland.
I bought my cells from Shenzhen Jidian on Alibaba. 272AH Lishen or CATL or EVE cells are fine. You string them together in series to create a 16S 48V bank.
I use the little Battgo monitor to make sure no cell goes above 3.65V when charging before top balance. The small power supply that is capable of Constant Current and Constant Voltage is used to top balance the cells at 3.65V. When amps decrease to zero, all the cells are at the same SOC.
The BMS monitors each cell to make sure the temp is OK, and the voltage stays within 2.5V and 3.65V.

I use the Heltec 200amp 2 amp active balance BMS from Heltec on Alibaba. It uses a 2 amp current to keep each cell within tolerance of each other.

Once the bank is built, then I put it in a metal box with a pre-charge resistor, a high amp battery switch, and a battery shunt to monitor capacity. My box is 48 inches by 16 inches x 14 inches, so I can fit 32 cells as two banks side by side in it. I use plastic cutting board and rubber matting to isolate each cell, and protect the terminals. I also add an RV 12V tank heater to assure the box stays warm in the winter, as the setup is in my garage, and Lithium Iron Phosphate (LiFePo4) cells do not like to be charged in the cold.
 

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My 3024MSE is doing the same thing. inverter is set to 24v switch to bypass. but it keeps charging the battery till it hits 24.5v and goes back to battery mode and repeat even though i have it set to OSO in the settings. Not happy.
 
The charge parameters seem to be a bit loose on how strict the voltage settings get enforced, but your BMS sbould be there to protect you. Perhaps set your back to battery a bit higher so it stops bouncing back and forth.
 
I got a decent reply from the MPP seller, (via ebay) he agreed that the manual is not clear. He at least bothered to rep,y, and was knowledgeable about the product.
There is no option to turn off utility charge, he explained it as they had issues with batteries being discharged for too long, and so removed the option. I don’t agree with that as surely it’s the users choice , and it’s so easy for them to give the option, but even I offered to pay to have it as a firmware update, it was refused. Seems the powland versions are an exact copy of the mpp units, but powland have no back up at all. We live and learn.
I have disconnected the utility supply , and now only run a well pump on 240vac when ever there is enough charge to work it, not at all what was intended, and very disappointing.
i would have thought that using lithium batteries would take care of the discharged time (overnight etc) , and suggested this, but again no co operation. So, search continues for a better unit, hybrid of min 5kw, if anyone knows, share the detail, Regards to all.
 
I got a decent reply from the MPP seller, (via ebay) he agreed that the manual is not clear. He at least bothered to rep,y, and was knowledgeable about the product.
There is no option to turn off utility charge, he explained it as they had issues with batteries being discharged for too long, and so removed the option. I don’t agree with that as surely it’s the users choice , and it’s so easy for them to give the option, but even I offered to pay to have it as a firmware update, it was refused. Seems the powland versions are an exact copy of the mpp units, but powland have no back up at all. We live and learn.
I have disconnected the utility supply , and now only run a well pump on 240vac when ever there is enough charge to work it, not at all what was intended, and very disappointing.
i would have thought that using lithium batteries would take care of the discharged time (overnight etc) , and suggested this, but again no co operation. So, search continues for a better unit, hybrid of min 5kw, if anyone knows, share the detail, Regards to all.
I emailed mppsolar, sorry the transcript is upside down>

New message from: maximum_solar Top Rated Seller(6,683Green Star)

I know what you're saying. It was designed this way because a few years back on the earlier generation models they could work this way, and in the end Mpp solar end up with a lot of customers complaining about their batteries don't last as long as they should as a result of the extended discharge of battery banks. Suppose you have bad weather conditions and then you have no solar. then you got no charging and this happens a lot more than what you think actually. And you can't rely on users remembering to change their charge settings anyway, so in the end the best thing to do is to just override the solar only charging setting when system switches to line mode. It's a tough call.​

Thanks,
Best Regards
Maximum Solar, Authorized Reseller of MPP Solar products
(maximumsolartw at gmail dot com)
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Your previous message
I don’t want to use ac over night to fully charge the battery when i have solar the next day. Its a waste of electricity. The idea is i run my printer farm off solar if battery goes dead one day then switch to ac bypass. Normally next day solar will charge it full again but if the battery is already full its wasting potential.​
maximum_solar:
You might want to rethink this over. The problem here is that your setting 12 and 13 are too close and when your battery falls to 12 and switches over to grid that means your output is far more than your input (solar power) so as a result it cannot keep the battery full. Then obviously it'll need to switch to grid for backup. There's no other choice. But keeping 13 too close to 12 means you'll end up with frequent switching which is bad for the system not to mention your battery will never get a full charge.

The key here is to look over your system planning and see if you can increase the solar power. That's what I would do. The purpose of grid charging battery under line mode is necessary to keep battery life long and healthy. Not a stupid thing at all. battery banks are expensive.​
Your previous message
This defeats the purpose of solar only. I drain battery one day till it hits bypass and then it charges over night full when next day i could use solar to recharge. But what its actually doing it switches to bypass for a short period then as voltage rises from charging it switches back to battery mode then drains again and repeats cycle until morning when sun comes out. Its stupid.​
maximum_solar:
It's supposed to do that.

the OSO (solar only) only works when under battery mode so even when utility is present, it'll only charge by solar. But when it enters LINE MODE (AC bypass), OSO no longer applies. This is shown in the manual.​
Your previous message
Seems to be an issue with my inverter. i have setting 16 set to 050 so only solar will charge the battery but when inverter switches from battery to ac bypass due to low battery it charges the battery via AC when it should only charge via solar if there is solar.​
 
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