Help with 4s pack and victron 100/20 MPPT

[waiapasi2006]

Hello everyone,

I need some help please.

I've wired up this system and it was working for a few days just to check the MPPT.
I've disconnected everything to place it in a secured box and now the MPPT won't turn on.
Battery: 4s 120 amp
MPPT: Victron 100/20
See pictures below.
Voltage on the terminal are 14.3V
Voltage at the BMS from + battery terminal to C- reads 13.35V

When I connect the MPPT directly to the battery, the blue light turns on.
When the MPPT is connect with the BMS, the voltage drops to 1.15v

Any pointer to what else I can do?

 

[Q-Dog]

Are you saying the 100/20 works when you bypass the BMS?

 

[waiapasi2006]

Are you saying the 100/20 works when you bypass the BMS?

Correct.

 

[Q-Dog]

Does anything else work when you connect it to the battery?

 

[waiapasi2006]

Connected directly to the battery and reads right away. Not sure what is happening here.

 

[Q-Dog]

The BMS is shut down for some reason?

 

[waiapasi2006]

Does anything else work when you connect it to the battery?

I'm going to connect a small inverter to test right now post back.

 

[waiapasi2006]

The BMS is shut down for some reason?

I've never seen this happened before. I also noticed the discharge parameter is set to off. It will not turn on even after a reboot. Reinstalled the app .... Very weird behavior.

 

[MisterSandals]

The BMS is shut down for some reason?

+1
At 14.3V on a new battery, my guess would be cell level over volt. Did you look at the BMS thru its app to see what state it is in?


And there it is, discharge turned off:

 

[waiapasi2006]

Does anything else work when you connect it to the battery?

With the BMS connect, nothing turns on.

 

[waiapasi2006]

+1
At 14.3V on a new battery, my guess would be cell level over volt. Did you look at the BMS thru its app to see what state it is in?


And there it is, discharge turned off:

Yes, at this point 14.2v. Could it also be this culprit? Broken temp sensor....

 

[740GLE]

Can you post the screen shot of all the BMS settings?

 

[42OhmsPA]

Apply a charge with a DC power supply and report back.

 

[740GLE]

I've never seen this happened before. I also noticed the discharge parameter is set to off. It will not turn on even after a reboot. Reinstalled the app .... Very weird behavior.

I have had that happen when I changed a setting in the BMS, it then shut off discharge once I saved it, I just toggles it back on and all was good.

Can you just toggle the discharge button? Also try the overkill app, some odd reason I enjoy that one way more.

 

[waiapasi2006]

Can you post the screen shot of all the BMS settings?

 

[waiapasi2006]

I have had that happen when I changed a setting in the BMS, it then shut off discharge once I saved it, I just toggles it back on and all was good.

Can you just toggle the discharge button? Also try the overkill app, some odd reason I enjoy that one way more.

I've used the overkill app as well. I'll give it a go once more.

 

[740GLE]

Balance start voltage should be 3.4v vs 3.2v

Also disable “balance while charging” this will have the BMS balancing even after solar is done.

 

[waiapasi2006]

I've used the overkill app as well. I'll give it a go once more.

So as mentioned, I wonder if the temp sensor could be the culprit to this. See the screenshots below with the warning.

 

[waiapasi2006]

Apply a charge with a DC power supply and report back.

I did add a charge with the voltage set to 14.5v and nothing takes place.

 

[waiapasi2006]

Balance start voltage should be 3.4v vs 3.2v

Also disable “balance while charging” this will have the BMS balancing even after solar is done.

Let me try that. I've not tampered with any settings there. Those are all standard from the app using LIFEPO normal setting.

 

[waiapasi2006]

I'm going to take apart the BMS and resolder the temp sensor to see if that has anything to do with it.

 

[740GLE]

In the Overkill app I think you can disable the sensor, all the way down at the bottom.

Mine is an older 200a 4s

 

[740GLE]

Let me try that. I've not tampered with any settings there. Those are all standard from the app using LIFEPO normal setting.

Yeah it it’s t linked to your issue your seeing now, but still good practice to only balance when cells are above 3.4v

 

[waiapasi2006]

Yeah it it’s t linked to your issue your seeing now, but still good practice to only balance when cells are above 3.4v

So, I got the temp sensors back on

 

[waiapasi2006]

In the Overkill app I think you can disable the sensor, all the way down at the bottom.

Mine is an older 200a 4sView attachment 277390

I've made these changes so far. Voltage at battery terminals are 14.25v
Voltage at positive and C- = 13.25V