Victron blue solar controllers

[Dod42]

I have 2 x Bluesolar MPPT 100/50 solar controllers attached to 2 separate arrays. I also have the Bluetooth dongle attached to both so I can monitor what is happening. The concern I have is that the controllers both report higher battery voltage than there is in reality. They charge a LifePO4 bank so I monitor them make sure all is good. The problem started with the controllers showing the battery voltage as being at 14.14 and 14.20 volts. Both above what I wanted and as they where the only charge source I couldn't see what was going on. When I put a meter ( and yes I checked this with 2 meters) the voltage across the battery terminals on the Bluesolar controller both showed 14.04. So it seems that one is reading 0.1 volts higher than reality and the other 0.16. I originally thought I had a voltage drop across my cables but seems to be an error with the voltage sense on the controllers.

I have emailed Victron support who are usually very good but have had nothing back. So the problem is, besides they don't report the correct voltages, is what charge settings should I set them to? Do I set them to 14.05 that I want or do I take the 14.05 and add the variance, and then do the same for the float voltage. I'm not sure yet but they seem to drop into float before what I think they should ( as float is almost off due to LifePo4). This would be due to them reading the battery as being higher voltage than reality. This makes me thing it's reading wrong all through the scale.

Anyone else had issues with this?

Btw I have upgraded their firmware to 1.16


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[mcarling]

There is no reason to charge LiFePO4 batteries at any voltage higher than 13.8V (except when performing an initial balance). I use 13.6V.

I would configure the charging voltage such that the charging voltage measured at the battery is what you want.