Hi all

I need some help please. I have a 2 KVA PWM 1500W fivestar 12V Solar Hybrid Inverter.  With a 50Ah lithium battery and one solar panel.  I only get 1hr and 30min running time during LS. I'm only running a small TV, wifi and a light. Load says 6%.  The settings are so confusing. I keep getting at low voltage battery error and ALA 235 error. Please help surely I should be getting more time than this.. what settings do I change ? 

With a 12V PWM system, you really need a "12V" panel, with a Vmp of around 17V. You are wasting more than half of your panel's output running it at around 14V or less most of the time. The best you could get would be around 13A x 14V ~= 180W, often more like 80% of this, or 145W.

I'm guessing that the battery is getting chronically undercharged, and it may already be ruined. You could add another panel in parallel, doubling the solar charge power. Or replace the panel with several 12V panels in parallel, but those are hard to get at reasonable prices. 

You could also update to an MPPT based inverter, or use an external MPPT solar charger connected directly to the battery. Or update to a 24V system, either MPPT or PWM. The external MPPT solar charger is probably the easiest and cheapest way. 

You may care to update to a lithium battery too, they are more expensive up front, but cheaper and less hassle in the long run. [ Edit: Duh! It already is. So most likely the battery is not ruined, but you still probably need more solar power to charge it. ]

Edited January 6, 20242 yr by Coulomb

Judging by the high number of cycles of the battery, this seems to be a 12V 50Ah lithium battery. This gives better chances that the battery is still okay. Also, OP said it is.

First issue is just that it's a very small battery, with 640 Wh storage capacity, so it will not last long before it's flat. Max 600W output on a 2kW inverter because of the choice of battery. A second battery will help to reach at least 2 hrs.

The panel is also not ideal for this inverter wrong as said above. Another panel will double the output, but again, it's not likely to be good value for the money.

In the end, unfortunately, not a very well put together system.

@donCT

Your load can't be more than 115w as per your appliances used. You have a 640wh lifep04 battery that should give you at least 5 hours coverage when fully charged.

Set parameters as follow:

00- UPS

01- LO

02- UTI

03- CUT 

04- 90%

05- 100%

06- 14.2V

07- 13.6V

The inverter is now set up for LS backup only. I am wondering if your parameters 02 was set to SBU and 03 to OSO and your panel is not capable of fully charging your battery. Send me all parameter setting if you get a chance just jot them down and take a picture. 

See if you get better results during load shedding your battery should be fully charged by uitility and if results are better we can work on your solar panels and another 50ah battery backup.

 

Edited January 6, 20242 yr by TaliaB

1 hour ago, TaliaB said:

@donCT

Your load can't be more than 115w as per your appliances used. You have a 640wh lifep04 battery that should give you at least 5 hours coverage when fully charged.

Set parameters as follow:

00- UPS

01- LO

02- UTI

03- CUT 

04- 90%

05- 100%

06- 14.2V

07- 13.6V

The inverter is now set up for LS backup only. I am wondering if your parameters 02 was set to SBU and 03 to OSO and your panel is not capable of fully charging your battery. Send me all parameter setting if you get a chance just jot them down and take a picture. 

See if you get better results during load shedding your battery should be fully charged by uitility and if results are better we can work on your solar panels and another 50ah battery backup.

 

Slight correction. I also get a load of 180W as per @Coulombcalculation. Reducing the 640W storage to 90% is 576W. Deducting say 8hrs of standing time(25W) after sunset before LS brings the storage to 376W. This leaves just 2hrs to run the load.

This only if battery was fully charged. Low PV charging might cause battery not to be full and run time will be far less. 

1 hour ago, Scorp007 said:

Slight correction. I also get a load of 180W as per @Coulombcalculation. Reducing the 640W storage to 90% is 576W. Deducting say 8hrs of standing time(25W) after sunset before LS brings the storage to 376W. This leaves just 2hrs to run the load.

This only if battery was fully charged. Low PV charging might cause battery not to be full and run time will be far less. 

Let's say we have 640wh lifep04 battery fully charged so we have 640wh- 10%= 576wh usable battery. Forget the 1 panel for now. Inverter is in passtrough using utility for loads and 3 watts self consumption from battery. 8 hours x 3 watts= 24wh used for self consumption. 576wh -25wh = 551wh capacity left. 1 small tv =~50watts wifi ont+ router ~ 25watts 1 x light cfl~ 11 to 14w total load =90 watts.

551/ 90 = ~6hours. This setup would cover 2 hours LS with no problem.

8 hours ago, Coulomb said:

You are wasting more than half of your panel's output running it at around 14V or less most of the time. The best you could get would be around 13A x 14V ~= 180W, often more like 80% of this, or 145W.

The 180w Coulomb was reffering to is the charge power from a 41v panel through a pwm charge controller with a battery voltage of 12v. 

Edited January 6, 20242 yr by TaliaB

30 minutes ago, TaliaB said:

Let's say we have 640wh lifep04 battery fully charged so we have 640wh- 10%= 576wh usable battery. Forget the 1 panel for now. Inverter is in passtrough using utility for loads and 3 watts self consumption from battery. 8 hours x 3 watts= 24wh used for self consumption. 576wh -25wh = 551wh capacity left. 1 small tv =~50watts wifi ont+ router ~ 25watts 1 x light cfl~ 11 to 14w total load =90 watts.

551/ 90 = ~6hours. This setup would cover 2 hours LS with no problem.

The 180w Coulomb was refering to is the charge power from a 41v panel through a pwm charge controller with a battery voltage of 12v. 

OK sorry my mistake. It just happens so that the OP mentioned 6% of 1500W and when I saw 90W I took it as X 2 by error. Then my error again by taking the standing load as from the battery. 

Hi all thanks for the input.  I changed setting 2 and 3 and yesterday I got 4 plus hours during the day.  I think I could have got more.  I've not tested in evening yet without the panel.. I will do the test today.   

7 hours ago, donCT said:

Hi all thanks for the input.  I changed setting 2 and 3 and yesterday I got 4 plus hours during the day.  I think I could have got more.  I've not tested in evening yet without the panel.. I will do the test today.   

I am glad it helped you out. Do you have any means of monitoring the soc of your battery maybe a  montoring system (eg solar assistant) or Victron Smart Shunt. How much battery current do you get from the the existing solar panel. Like @Coulomb pointed out you can use 4 off these panels in parallel with Vmp of 18v

https://www.securityandmore.co.za/products/cinco-120w-36-cell-poly-solar-panel-off-grid?variant=29189080350772&currency=ZAR&utm_source=google&utm_medium=organic&utm_campaign=Google Ads Feed Oct 2022&utm_content=Cinco 120W 36 Cell Poly Solar Panel Off-Grid&gad_source=1&gclid=Cj0KCQiAtOmsBhCnARIsAGPa5yYHqzko1CiLOI4h5b2aNYGvTpbC72XNWIJf3WudONvyWEbZwL8LWpIaApQGEALw_wcB

Bravo @TaliaB I am still trying to wrap my head around how to deferentiate between Mppt and Pwm charge controllers but i will leave that to you solar installers. My Fivestar 3kva is supplying power during the day without using Eskom power with setting SBU and OSO. During evenings when my load is minimal (120watts) my battery is charged up by 10h00 in the morning 🌅.

@Steve87 Nice pics of your install at Wits University @TaliaBsent me through some pictures of your ATESS install and is twisting my arm to go for the ATESS instead of the 50kw Deye with FW HV battery. Very professionally done Steve and great workmanship you guys surely now your stuff. Just one question from my side at the moment my 3ph supply from Eskom is very unbalanced as i have installed maximum demand meters a few years ago on each phase that i monitor, would that be a problem. The biggest load is 2x 10kw centrifugal irregation pumps. @TaliaB has done all the site load requirements and 50kw should be in the ball park as i understand tha ATESS HPS 50 is rated for 72 amps on and off grid. Thanks guys have a good one.

Hi @Derek3thanks for the kind words. I have grown to like the ATESS in my journey with it. There is a lot of stuff to know as with any new piece of equipment. It also doesn't perhaps suit every site & the reasons are a few. The machine is more expensive than a 50kW Deye or Sunsynk. 

But one cannot compare these 2 products. One can run inductive loads with relative ease due to its architecture. The other is still IGBT & MOSFET driven. This is much more suited for residential or light commercial projects. 

The ATESS has its quircks and they are the following: It needs more space & requires some handling equipment like Forklifts & Pump trucks. The Low Frequency transformer based architecture makes their units Heavy, the HPS50 in the region of a shave under 800kg. We removed the transformer in the Wits project & it weighed 575kg alone. That weight and the solid copper in that machine is the main reason it runs inductive & capacitive heavy loads for fun. 

It has 1 MPPT, which doesn't work for every site. If you have a limited roof orientation the only other work around is to AC couple with Grid tied inverters on the AC output. But if you have a decent sized roof or PV space the 1MPPT is a monster & can take 75kW of PV power. The inverter can also run at 55kW for up to 10mins & up to 60kW for 1 min. So it can handle a fair amount of abuse. Not that one plans to use it like this but it's a good to know. 

The settings are a bit tricky to understand but if a good operator that has the required knowledge sets her up or gets the required training it's a piece of cake. It also employs a work mode timer & can be also changed remotely using the Enerlog, 

All in all, you are buying a totally different type of machine, you are buying a machine that is serviceable in the field & is made up of industrial switchgear comprising massive Contactors & relays. It's very heavy but once it's in, you won't move her again. 

The Deye or Sunsynk would return for an RMA for investigation etc. the ATESS will point a service engineer in the correct direction based on its History page that will point out the problem. There is a parts pool in FreedomWons warehouses as well as locally with ATESS who are based in Midrand. FreedomWon recognized the ATESS potential & agreed to carry out battery & inverter pairing & supported their path into SA. For all the large commercial Installations it's hard to find other suitable products that match the quality & purpose of this machine. 

Having worked on Victron systems, this is the last step that Victron did not take. High Voltage DC scale-able from 30kW sized inverters all the way up to 4MW sized plants. 

@Derek3& @TaliaBenjoy the journey. It's one that many will take after you & you won't regret the experience.