dacool1:

Thanks.

I was wondering what would happen should BMS shut down in order to protect the battery.

I have this fear too, imagine your battery emptied before the sun comes up

olopan:
A BMS would completely shutdown in certain conditions, at other times they would keep working.

1. If the charging voltage is high and the cell voltage reaches the cut off voltage then, it will either shutdown or just cut off charging there by making the battery still available for use as only inverter. (i could be wrong, as i have less experience with DIY LITHIUM)

Shutdown as a result of completely drained battery

Incase u won sell those batteries. Post them here. I might b interested.

drered:


Cost me about 1.1M 2 years ago.

If this scenario was to be the case, and your BMS was properly configured to prolong your cell life with recommended settings then only the discharge part of the BMS will go off, while the charge part stays on.

when you need it to charge, it will receive the charges fine.

oloet:


Shutdown as a result of completely drained battery

olopan:
If this scenario was to be the case, and your BMS was properly configured to prolong your cell life with recommended settings then only the discharge part of the BMS will go off, while the charge part stays on.

when you need it to charge, it will receive the charges fine.

Just to add based on Daly BMS i use, if LVD is reached you will have to disconnect load for few seconds for BMS to restart, last time this happened my inverter went into fault mode as it tries to wake BMS but Discharge FET is off so its seeing No battery.

Incase of HVD, there is no issue.
Inverter stops charging but still have Battery connected as it still see battery with Discharge FET turned on. See attached

oloet:


Shutdown as a result of completely drained battery

A proper setup, Lvd and hvd should primarily be done by the inverter. With the bms being the plan b/fall back.

Using the bms as primary lvd and hvd disconnect is wrong and may lead to present and future troubles.

Eg set inverter Lvd at 3.0v and bms at 2.8v

olopan:
If this scenario was to be the case, and your BMS was properly configured to prolong your cell life with recommended settings then only the discharge part of the BMS will go off, while the charge part stays on.

when you need it to charge, it will receive the charges fine.

Does this apply to a BMS that uses same bus for charge and discharge

earthrealm:


A proper setup, Lvd and hvd should primarily be done by the inverter. With the bms being the plan b/fall back.

Using the bms as primary lvd and hvd disconnect is wrong and may lead to present and future troubles.

Eg set inverter Lvd at 3.0v and bms at 2.8v

My inverter is dumb that the BMS shuts down before it, quite sad....

Chichilas:


Check the moniker well, you would know my problems.

Hope you are not mistaken Revo ii and Revo ii pro. The Revo ii I know are very rugged.

Revo ii pro has touch screen issues when there's mains although this can be corrected by earthing the inverter.

Dam5reey:


Just to add based on Daly BMS i use, if LVD is reached you will have to disconnect load for few seconds for BMS to restart, last time this happened my inverter went into fault mode as it tries to wake BMS but Discharge FET is off so its seeing No battery.

Incase of HVD, there is no issue.
Inverter stops charging but still have Battery connected as it still see battery with Discharge FET turned on. See attached

If your mains had come on when your inverter is sensing no battery. Chances are high it could blow up the FETs.

zeestone99:


If your mains had come on when your inverter is sensing no battery. Chances are high it could blow up the FETs.

Nope as I switched on the Grid, It switched to NO battery mode as it works without battery.

It was PV (High VOC)that was trying to wake the BMS, but it went to fault after 2 tries and says no battery.

And worked without battery.

Also when the inverter send current to charge, it start’s gradually from 0.1A and cranks up so there is no fear of blowing up, it does not push high current to charge.

Dam5reey:


Nope as I switched on the Grid, It switched to NO battery mode as it works without battery.

It was PV (High VOC)that was trying to wake the BMS, but it went to fault after 2 tries and says no battery.

And worked without battery

Good. Exactly how it should.

sintolord:
Maybe, Sorotec use to make them good. When I bought my, the Sorotec logo was poorly printed on the inverter casing. I had to send the picture of the inverter & logo on it to Sorotec & they confirmed the inverter was made by them. It only worked for abt 4 months & died. I had to replace it with Felicity. Atleast, if anything happens to it within warranty, Felicity will take responsibility & repair it. That can not be said of Sorotec

Post a picture of the particular Sorotec model, lets see. I am a fan of Sorotec and premature failure by unknown causes isnt among its known faults.

Revo ii is their flagship brand and quite reliable.confirm this is yours

drered:


Cost me about 1.1M 2 years ago.

Alright

My revo vm ii pro. See pics. The list of the inverters problem were endless. I was not shocked when it finally gave up the ghost

earthrealm:


Post a picture of the particular Sorotec model, lets see. I am a fan of Sorotec and premature failure by unknown causes isnt among its known faults.

Revo ii is their flagship brand and quite reliable.confirm this is yours

sintolord:
My revo vm ii pro. See pics. The list of the inverters problem were endless. I was not shocked when it finally gave up the ghost

OK, YES, THIS ISNT THE SOROTEC FLAGSHIP MODEL WITH TOUCHSCREEN DISPLAY. this is the vm ii, one of their budget models. sorotec has been in existence for 15yrs---am sure they would have folded and closed shop, if they are known for churning out wonky products

endless problems,, would be great if you can share a few of the problems........perhaps 2 or 3 for starters

Bus as in on the BMS itself or at the charger/inverter side.

oloet:

Does this apply to a BMS that uses same bus for charge and discharge

You will need an external LVD device that does the job for you, that way you won't have issue waking up the battery.

oloet:


My inverter is dumb that the BMS shuts down before it, quite sad....

Milito:


Thank you.

Please do you or anyone here have any experience with Index NXT Lead Acid battery? Is it a good battery?

I've always been using Full River Batteries, but I'm considering using this Index NXT as that is what Prag is offering for sale with the inverter I want to purchase from them.

Full River vs Index NXT batteries. Please what is the verdict folks?

The Index brand of batteries are also a very good brand of lead acid batteries. They also have an authorized reseller in Nigeria Multipower Global Solutions. I just hope that the ones Prag are going to supply you are the genuine ones. But your in good hands with Index.

TBB 1.6KV 24v or Schneider Homaya 1500VA?

I want to move the 24v inverter that has been in my parent's place to somewhere new.

I want to get a replacement for them today but I'm torn between the options above.

For anyone with experience with them, which would be the best of the two for me to get?

I'm using it with 2 gel batteries though should upgrade to lithium later in the year.

bodeface:
Happy Sunday to everyone!
Please, I need help from experienced installers, users and DIYs.

I am planning to upgrade my inverter system, am looking at buying a 5KW 48V Hybrid inverter (with solar DC input of 450V minimum), I have read of so many brands, I am trying to leverage on the experience of the forum to know which brand and model is considered stable, low idle consumption, compatible with lithium battery (future plan), low failure rate and the cost is within 350 - 400K (slight increase above budget could be accommodated for value and reliability)

Experienced seniors, pls help with brand and models based on experience, these toys aren't cheap anyone, one has to choose wisely.

Try out the new SRNE HES4855S100-H with 500 VOC built in MPPT. It can power up to 4HP loads and has an ECO mode for low idle consumption. Its selling price as at Dec 2022 was N600,000. But they have an authorized dealer (HM Solar) that can handle warranty and repair issues if you encounter any.

Good day everyone, I have a concern. with the increase in size of a single pv panel capacity now up to 600watts panel, does this not make the panel more fragile without having frames in between to brace the 4 edges? and the weight also considering lifting them on high roofs. Has anyone thought about this before?

Battery was always showing 100% on the app even when the voltage drops to about 25v or below.

Also, total power generation is always showing 0.00kwh on the App. You can imagine that I paid 30k extra for the wifi dongle.

On the inverter display screen amp charging the battery is greater than the power generated from the solar panels.

After switching off all load from inverter and no PV power is coming in( night), the fan does not stop working.

Once you put a load like electric kettle, microwave or cooker of abt 1.2kw on it, the load in kilowatt can fluctuate from almost zero to 1.8kw.

When you put 2 of those load on it, the inverter switches off. I guess overload due to fluctuation. I guess the inverter was over rated to 3.5kw

Many other issues I can't even remember.

earthrealm:


OK, YES, THIS ISNT THE SOROTEC FLAGSHIP MODEL WITH TOUCHSCREEN DISPLAY. this is the vm ii, one of their budget models. sorotec has been in existence for 15yrs---am sure they would have folded and closed shop, if they are known for churning out wonky products

endless problems,, would be great if you can share a few of the problems........perhaps 2 or 3 for starters

Are you in need of a Rugged Industrial UPS for your Power BackUp Solution. We have all sizes of Vertiv/Emerson UPS in stock and we have well Trained Engineers for Maintenance. We are located in Abuja and Lagos. You can Call/Watsapp us on 08066332919

viperVIP:
Good day everyone, I have a concern. with the increase in size of a single pv panel capacity now up to 600watts panel, does this not make the panel more fragile without having frames in between to brace the 4 edges? and the weight also considering lifting them on high roofs. Has anyone thought about this before?

I am guessing you might be referring to the 600W HiKu7 Canadian Solar panel currently sold by Techland and Gennex. This panel alone weights 31kg. So, if you have 10 of them on your roof you have added 310kg onto your roof. An average bag of rice is 50kg so that is equivalent to about 6 bags of rice on your roof. This is apart from the aluminum rack mount system that will need to be installed to place the solar panels on them thereby adding more weight. The 600W panels are mainly considered for utility installations (solar power plants) and not residential use even though they can be used for that. The main range for residential solar panels are from 72HC cells to 144HC. in wattage that's from about 350W - 450W. Anything beyond that range and your entering the big boys leagues. However, the major advantage that these panels offer is that they reduce the need for more panels to achieve higher wattage. And they come with larger wafer sizes for the cells making them generate more power faster. However, you must first make sure that your roof can be able to withstand the stress of such a heavy load before install. They are not fragile in the sense as they are built with quality in mind but its the weight that they add on your roof that is the issue. Those whose roofing beams are inadequate to handle the load should not be installing such huge panels. However, they also have some advantages to consider. Kindly check out the link below:

https://www.cleanenergyreviews.info/blog/most-powerful-solar-panels

plenty annoying problems, kpele....., below in green are some of my thoughts on the issues, you had

sintolord:
Battery was always showing 100% on the app even when the voltage drops to about 25v or below.

Also, total power generation is always showing 0.00kwh on the App. You can imagine that I paid 30k extra for the wifi dongle. -------- app issue, perhaps tried uninstall and reinstall, or another app?



On the inverter display screen amp charging the battery is greater than the power generated from the solar panels. -------- you said amps, not watts, hope you know for mppt, 3amps 389v might be coming in from panels, and the mppt will change it to 15amps, 56v?
edit: looked at your old posts, I would guess you would be aware of this phenomenon, so again perhaps that your particular unit had fault



After switching off all load from inverter and no PV power is coming in( night), the fan does not stop working. ------ might be an issue unique to your particular device, or perhaps you didn't wait long enough perhaps up to 5mins, mine doesn't behave like this



Once you put a load like electric kettle, microwave or cooker of abt 1.2kw on it, the load in kilowatt can fluctuate from almost zero to 1.8kw.-------------yes, the load meter on most budget inverters are not very accurate


When you put 2 of those load on it, the inverter switches off. I guess overload due to fluctuation. I guess the inverter was over rated to 3.5kw------- what size and type of battery do you have to load 2 electric kettles on your setup? .. most invertes get more inefficient as you are loading it towards the max capacity, and this is worse on budget inverters. 2ndly it might even be your battery sagging and tripping the LVD, if you are using leadacid batts or the bms cutting off if you are using lifepo4 battery etc, did you observe your battery voltage b4 the inverter turns off?

Many other issues I can't even remember.

samir101ng:


The Index brand of batteries are also a very good brand of lead acid batteries. They also have an authorized reseller in Nigeria Multipower Global Solutions. I just hope that the ones Prag are going to supply you are the genuine ones. But your in good hands with Index.

Please, I will like to get your input on Eastman tubular battery in terms of qualitywise. Does the battery worth investing on?

Now I understand.
Thank you!

samir101ng:


https://www.cleanenergyreviews.info/blog/most-powerful-solar-panels

Gurus in the house, please help to identify which of these Must 3KW inverter is better, in terms of durability, efficiency and longevity.

My reply to your suggestions or questions;

1, App issue, perhaps tried uninstall and reinstall, or another app?

I abandoned the inverter. I now use Felicity and it's working as it should. Mind you, it's about 100k cheaper. Though, Felicity is 24v 3kw, MPPT 100a while Sorotec is 24v 3.5kw, MPPT 100a.

2, You said amps, not watts, hope you know for mppt, 3amps 389v might be coming in from panels, and the mppt will change it to 15amps, 56v?

Imagine 1500w coming in from solar panels & inverter is shows it's using 70a to charge battery.

3, Might be an issue unique to your particular device, or perhaps you didn't wait long enough perhaps up to 5mins, mine doesn't behave like this.

There was a day, I had to wait for about 2hrs after load has been switched off and the fan is working like I loaded to 80%.

4, Yes, the load meter on most budget inverters are not very accurate.

Well, I bought the inverter because seller told me Sorotec build there inverters with quality components.

5, What size and type of battery do you have to load 2 electric kettles on your setup?

24v 15kwh, lifpo4

6, Most invertes get more inefficient as you are loading it towards the max capacity, and this is worse on budget inverters. 2ndly it might even be your battery sagging and tripping the LVD, if you are using leadacid batts or the bms cutting off if you are using lifepo4 battery etc, did you observe your battery voltage b4 the inverter turns off?

I have a Tomzn voltage/current protective devise connected to my setup. Max 2500w load is allowed. Anything above, the device will trip off. If inverter is rated 3500w & I occasionally do close to 2500w. I still have a gap of 1000w. I am no where near the max capacity of inverter. Battery is 24v 15kwh, so it has nothing to do with the battery.

The day the inverter died with a loud bang, LG 1.5hp inverter compressor AC & Thermocool 219 liters (not exactly sure) freezer were the loads on it.

Bottom line is, inverter is poorly built. Probably built for Bangladeshi market

earthrealm:
plenty annoying problems, kpele....., below in green are some of my thoughts on the issues, you had

Ah! 1.5hp AC on a 3.5kw 24v HF transformer based inverter is plenty o

As you may know the HF inverters do not like inductive loads - they have virtually zero surge handling and what they do have is usually for 1 or 2 cycles - read like much less than half a second - although you may have an inverter AC, the variable speed motor will still present an inductive load. The physics limitations of switch mode power supplies must be respected as in an HF inverter lacking a large iron core/toroidal transformer they perforce cannot handle the surges and transients created as inductive loads go on and off (when your AC compressor picks up or cuts off). The ability of your inverter to handle surges and transients is directly proportional to the amount of iron present in the transformer due to something called the 'flywheel effect' . LF transformer based inverters rated for large loads have plenty of iron (more than needed for the application) in their transformers and the FETs switch much slower (hence low freq) and are often large sized and designed to run much cooler - all these factors surges/voltage spikes & transients/ back emf/reverse current/flywheel effect running temps etc impact how well your inverter does with surge loads.

In simple English most budget HF inverters are sorely lacking in the internals needed to run those large and problematic loads robustly for a long time.

There is also the issue of large loads on a 24v system - it is amps flow that makes cables and power electronics heat up which is why you may have seen your fan run more than you expected.

2,000w load on your 24v nominal LFP bank is 75a flowing through the inverter DC bus - even in a premium system 75a is significant energy flow talk less of a budget el cheapo with lower grade components.

I think you may have pushed the device beyond it's real hardware limits. It is not uncommon for the capacities and tolerances of el cheapos to be overstated.

sintolord:

.....
I abandoned the inverter. I now use Felicity and it's working as it should. Mind you, it's about 100k cheaper....

Well, I bought the inverter because seller told me Sorotec build there inverters with quality components.


I have a Tomzn voltage/current protective devise connected to my setup. Max 2500w load is allowed. Anything above, the device will trip off. If inverter is rated 3500w & I occasionally do close to 2500w. I still have a gap of 1000w. I am no where near the max capacity of inverter. Battery is 24v 15kwh, so it has nothing to do with the battery.

The day the inverter died with a loud bang, LG 1.5hp inverter compressor AC & Thermocool 219 liters (not exactly sure) freezer were the loads on it.

Bottom line is, inverter is poorly built. Probably built for Bangladeshi market

NiyiOmoIyunade:
Ah! 1.5hp AC on a 3.5kw 24v HF transformer based inverter is plenty o

As you may know the HF inverters do not like inductive loads - they have virtually zero surge handling and what they do have is usually for 1 or 2 cycles - read like much less than half a second - although you may have an inverter AC, the variable speed motor will still present an inductive load. The physics limitations of switch mode power supplies must be respected as in an HF inverter lacking a large iron core/toroidal transformer they perforce cannot handle the surges and transients created as inductive loads go on and off (when your AC compressor picks up or cuts off). The ability of your inverter to handle surges and transients is directly proportional to the amount of iron present in the transformer due to something called the 'flywheel effect' . LF transformer based inverters rated for large loads have plenty of iron (more than needed for the application) in their transformers and the FETs switch much slower (hence low freq) and are often large sized and designed to run much cooler - all these factors surges/voltage spikes & transients/ back emf/reverse current/flywheel effect running temps etc impact how well your inverter does with surge loads.

In simple English most budget HF inverters are sorely lacking in the internals needed to run those large and problematic loads robustly for a long time.

There is also the issue of large loads on a 24v system - it is amps flow that makes cables and power electronics heat up which is why you may have seen your fan run more than you expected.

2,000w load on your 24v nominal LFP bank is 75a flowing through the DC bus - even in a premium system 75a is significant energy flow talk less of a budget el cheapo with lower grade components.

I think you may have pushed the device beyond it's real hardware limits. It is not uncommon for the capacities and tolerances of el cheapos to be overstated.

I was even thinking it's a 5kw inverter the guys is loading a 1.5hp ac and freezer. Freezer alone has 5x to 10x starting power draw ( for a 150w freezer, that's like 700w to 1.5kw.
1.5hp ac is draws about 1.6kw to 2kw.
I'm pretty sure other minor loads were on - like light and fan.
It's insane to expect 3 5kw output from a 3.5jw inverter rated to just 5s at 105% load. It mean at 100%, it may just be less than 15min. Better inverters are rated to say 110% continuous load.

Again, he didn't even consider power factor of those loads.