Bubbling sound with new AGM battery bank

[off.the.grid]

Or disabling temp comp if the system permits that.



Yep. Higher voltage when cold, lower voltage when hot.



Agreed.



Agreed.



Show us.

Temp comp is expressed as a total or a per cell value. You sometimes have to do the math to get it right.

My Trojans were -.005V/°C/cell

I had 24 cells, so I had to enter, -.005 * 24 = -0.12V/°C or -120mV/°C as the Victron MPPT wanted to see it.

The epever controller specifies per cell I think (mv/degrees C/2V) default is -3mv.

Datasheet is here.

https://waveinverter.co.nz/wp-content/uploads/2014/01/E2-270-2018.jpg

Says temp coefficient is -30mv /degrees C

I'm assuming that would be per 12V so would that make it -5mv that I set the controller to?

 

[sunshine_eggo]

The epever controller specifies per cell I think (mv/degrees C/2V) default is -3mv.

Datasheet is here.

https://waveinverter.co.nz/wp-content/uploads/2014/01/E2-270-2018.jpg

Says temp coefficient is -30mv /degrees C

I'm assuming that would be per 12V so would that make it -5mv that I set the controller to?

Yes.

 

[off.the.grid]

Ok sweet, so given these settings are within spec. I should just leave it as is and just walk away and forget?
Still feel uneasy about bubbling, but if it's within the specs as per temperature, etc then I shouldn't need to worry and just consider it as normal.

 

[sunshine_eggo]

Ok sweet, so given these settings are within spec. I should just leave it as is and just walk away and forget?

Yes.

Still feel uneasy about bubbling, but if it's within the specs as per temperature, etc then I shouldn't need to worry and just consider it as normal.

Yes.

 

[off.the.grid]

Sounds good, should hopefully get it all going this week

 

[off.the.grid]

Well I got everything switched over yesterday and all seems like its working OK.
However, there is still some unbalancing between the batteries, despite them all been left in parallel to charge over the last week.
Seems to be about 0.3 V difference between all the batteries.
2 batteries are reading in the 12.6V range, one is in the 12.7V range and another is in the 12.4V range. (these were taken after they finished charging at night)
They dont appear to be making much noticeable bubbling while charging, unless I put my ear right up to them.
I might need to invest in a battery balancer perhaps, but is 0.3V too much difference? Ive lowered the voltage a bit to make it a bit safer for the time being.
Ive read that one way to balance the batteries is to put them on float voltage levels for about a month, but i dont know how effective that is.
Ive already charged them individually for a a whole day each prior, so I dont know if i can get it any better or not.