480w 24v system off grid installation issues

[Mark Illingworth]

Purchased 4 panels two 12v Lithium batteries , 1500W inverter peak 3000W, 60A Charge controller. Had a faulty panel which i had replaced when I teste each panel. Have panels connected in series and parallel as instructed by seller. Also batteries in series for 24v system.
My issue is my inverter has practically exploded twice. The first after a couple of months. I assumed I wired something wrong somewhere. The second one I purchased exploded with in 10 minutes of connecting it to the batteries. Something popped inside and then the whole room filled with smoke. Returned this assumed faulty.
My concern is whether it's the charge controller causing issues with the inverter.
I'm getting 26.4v from two batteries which sounds about right as full battery is 13v ish. The second inverter I got was a larger one because I thought it may be needed so I got a 2000W 24v inverter.
Is 26v from battery causing my inverter to fail when it is a 24v inverter? Seems a little excessive. All cable connections appear ok.
The other factor that may cause an issue is my charge controller appears to be over charging battery. As soon as I connect the panels to the charge controller i get 30v showing and it gradually creeps up. So may be the charge controller is faulty but causing inverter to blow almost immediately, I'm not convinced.
Any help much appreciated!
Kind regards
Mark. I

 

[MrThisIsME]

Specs on panels and charge controller?

As soon as I connect the panels to the charge controller i get 30v showing and it gradually creeps up.

Making assumptions here, but I assume you are seeing a higher voltage (open circuit) before you connect the panels? Without all the specs, this is normal to see a voltage drop when connecting a load.

 

[Mark Illingworth]

My voltage with just the charge controller and batteries connected is 26.4v. When I connect the solar panels it jumps to 30v immediately and creeps up to as much as 35v. Battery overload light flashes on charge controller so I disconnect. At this stage I haven't connected any inverter. The last Inverter I connected fried 10 minutes after connecting it to the batteries with the solar panels connected. I'm assuming to much voltage going to the inverter and it may be a charge controller issue. However I am shocked how easily the inverter fried without any cut off mechanism when the voltage from batteries was between 26v and 30v. Can't remember what the voltage was exactly from batteries but it was likely around 26.4v.

 

[12VoltInstalls]

Well reveal what the panels are, post spec plate. That sounds like normal charging voltage for 100W 2S2P in moderately good sun.

What brand and model of inverters were they?

 

[Mark Illingworth]

The first one that fried after 2 months was a

1500W DC 24V to AC 220V Inverter from Ecoworthy​

The second that fried after just 10 minutes of connection to the battery with charge controller and solar panels briefly connected.

EDECOA 2000w 24v Pure Sine Wave Power Inverter 24v DC to 240v AC​

Obviously these cost money so I don't want to buy another one yet until I know if there is something fundamentally wrong I am doing. Plus they practically explode filling the house with smoke. Connections are tight from battery to Inverter and cables look fine.

I'm convinced it is the charge controller but I'm shocked at the results on the inverter so quickly.

Kind regards
Mark.I

 

[Pi Curio]

My voltage with just the charge controller and batteries connected is 26.4v. When I connect the solar panels it jumps to 30v immediately and creeps up to as much as 35v. Battery overload light flashes on charge controller so I disconnect. At this stage I haven't connected any inverter. The last Inverter I connected fried 10 minutes after connecting it to the batteries with the solar panels connected. I'm assuming to much voltage going to the inverter and it may be a charge controller issue. However I am shocked how easily the inverter fried without any cut off mechanism when the voltage from batteries was between 26v and 30v. Can't remember what the voltage was exactly from batteries but it was likely around 26.4v.

Hi Mark,

I don't have much of experience with solar in general. Yet, after reading this thread I've looked up about it. I've found this troubleshooting article with a lot of info on inverters.

Maybe there's something in there that might give you an idea what could be wrong with your system.

https://www.linkedin.com/pulse/common-inverter-problems-solutions-shola-peters-adegoke-itil-

It's quite an interesting read really.

Best,
D

 

[Mattb4]

My 2000w 24vDC inverters manual specifically says if input is higher than 30vDC that a buzzer will whistle continuously and the unit will shutdown with a display of Fault 3 on its LCD screen. If your inverters do not have a high input voltage cutout than you would fry them if your SCC is outputting 30-35vDC.

One other thing in my manual it says if you get a high voltage alarm that you should cease charging while using it.