Hi guys, I've now had my house trip on 2 seperate occasions during loadshedding and I think it is battery performance related and I'm not understanding 1. if my assumption is correct (that it's battery related) and 2. if it's normal.

Both times it appears to be usage in the home going over a certain level, I believe its somewhere between 3.1 and 3.3kw (though I can't 100% pinpont it).

My system is an 8kw Deye Inverter with 2x 4.8kw Dyness batteries (A48100) so I thought that it would be able to handle a load of up to 8.8kw on the inverter before tripping.

This feels like a battery output issue to me based on the graph below.

I'm a novice so any advice/perspective would be welcome.

 

My question

Have I misunderstood the capability of the system to handle load during loadshedding (i.e. it's normal), is something wrong with my system, or is it a settings related issue?

 

Additional info

The pic shows some stats from solarman (Inverter output, Grip power, Battery power and Total consumption/power). To my untrained eye, this is what I'm noting.

1. It looks like the battery power provided tops out at arounf 3.3kw with the inverter output at about 3.15kw (like the portion with the green line above it, which was not during loadshedding and so was supplemented by grid power when it went over 3.3kw consumption)
   1. >>> This is where my main question comes in, is that normal given my batteries? Is it a settings issue?
2. It tripped below where I marked the green X (it likely went above the 3.15kw, but didn't show it on the graph, it tripped after a kettle went on)

Let me know if you need any more detail than I've provided above. 

Battery settings:

Edited November 22, 20223 yr by Glenn

49 minutes ago, Glenn said:

Hi guys, I've now had my house trip on 2 seperate occasions during loadshedding and I think it is battery performance related and I'm not understanding 1. if my assumption is correct (that it's battery related) and 2. if it's normal.

Both times it appears to be usage in the home going over a certain level, I believe its somewhere between 3.1 and 3.3kw (though I can't 100% pinpont it).

My system is an 8kw Deye Inverter with 2x 4.8kw Dyness batteries (A48100) so I thought that it would be able to handle a load of up to 8.8kw on the inverter before tripping.

This feels like a battery output issue to me based on the graph below.

I'm a novice so any advice/perspective would be welcome.

 

My question

Have I misunderstood the capability of the system to handle load during loadshedding (i.e. it's normal), is something wrong with my system, or is it a settings related issue?

 

Additional info

The pic shows some stats from solarman (Inverter output, Grip power, Battery power and Total consumption/power). To my untrained eye, this is what I'm noting.

1. It looks like the battery power provided tops out at arounf 3.3kw with the inverter output at about 3.15kw (like the portion with the green line above it, which was not during loadshedding and so was supplemented by grid power when it went over 3.3kw consumption)
   1. >>> This is where my main question comes in, is that normal given my batteries? Is it a settings issue?
2. It tripped below where I marked the green X (it likely went above the 3.15kw, but didn't show it on the graph, it tripped after a kettle went on)

Let me know if you need any more detail than I've provided above. 

Battery settings:

Please help me understand if my thinking is right on this or if I'm off base.

My batteries have been set to a max current of 70A and have a certain voltage based on SOC, at most it's around 53.5v. So does that mean the max power I can draw from the batteries at any one time is (at 100% SoC) 53.5vx70A = 3,745kw and if I go over that during load shedding it will trip?

Edited November 22, 20223 yr by Glenn

Your Battery Max Discharge is set to 70amps. 48volts x 70amps = 3360w. Below is the data sheet for your battery. Max discharge is 75A per battery so you can change the setting on the inverter to 150A. This will give you about 7.2kw from the batteries.
 

If you need more then you can set it higher as you can see in the data sheet they can peak to 100A each for 15s. The BMS will protect the batteries in this case and probably trip before the inverter does. But pulling this much juice from your batteries too often will shorten their life.
 

Thanks @BrettB!

I was wondering if the setting on the Deye inverter was per battery or for the whole bank. Are you saying it's for the whole bank? (e.g. my 70A setting is actually making it 35A per battery at the moment).

Also, the way the batteries work, does 2 batteries in this kind of setup mean I can pull twice the amps? i.e. their current and power output is additive (75A + 75A)

As you can tell I'm new to all of this.

You can safely set max charge and discharge current to 150A. The batteries are in parallel so current (A) is added up while potential difference (V) stays the same. My grade 6 daughter built a little model this year to prove just that

Edited November 23, 20223 yr by Scubadude

12 hours ago, Glenn said:

Thanks @BrettB!

I was wondering if the setting on the Deye inverter was per battery or for the whole bank. Are you saying it's for the whole bank? (e.g. my 70A setting is actually making it 35A per battery at the moment).

Also, the way the batteries work, does 2 batteries in this kind of setup mean I can pull twice the amps? i.e. their current and power output is additive (75A + 75A)

As you can tell I'm new to all of this.

Yeah, with the battery max amps set to 70A you are limiting each battery to 35A. The settings on the Deye should be set too the capabilities of your entire battery bank. If each battery can do 75A then 2 batteries can do 150A. 4 batteries can do 300A, Etc.

This is why its so important that all battery cables to the inverter are the same length so the current is split evenly when charging and discharging. 

@BrettB / @Scubadude thank you!

That makes sense. I'll adjust the settings this evening

Thanks BrettB. I am having exactly the same issue with the exact same installation. I will also be setting the discharge to 150A.