Daily leisure battery capacity loss

[Arnoud64]

What is causing the daily leisure battery capacity loss?
When parked without sun on the solar panel, according to the BMS data, I lose almost 4 Ah per day from my two 100 Ah SuperB Epsilon LiFePO4 batteries with nothing switched on in the camper. See the picture for the continuous 0.2 A power consumption from each of the two batteries.
With a modest power consumption of 20 mA for the Victron SmartSolar 75/15 and 5 mA for the Eyon GPS tracker that makes only 0.6 Ah power consumption per day that I can explain.
Does the controll panel consume that much power?
For a California T6.1 with the standard AGM batteries and a usable capacity of 75 Ah this must really be noticable in a couple of days.

 

[Roger Boeken]

don't worry too much.
you are looking at the limitations of the BMS.
Precisely measuring small currents is not straightforward.
Epsilon 100 battery specifications : 190A discharge current continuous
To measure discharge current 190A with 0,2 A accuracy you need 0,1% accuracy !
I believe the app can only show +/- 0,2 A(resolution) and accuracy is probably even less.
The same story for original VW AGM batteries and control panel : some show 0A others always show -1A with no consumers switched on.
your estimation of discharge :
power consumption of 20 mA for the Victron SmartSolar 75/15 and 5 mA for the Eyon GPS tracker
I believe during readout with app Bluetooth increases consumption of victron MPPT.
Epsilon 100 self discharge < 3%/month =>0,1Ah/day
This adds up 0,7 Ah/day discharge.

 

[Arnoud64]

don't worry too much.
you are looking at the limitations of the BMS.
Precisely measuring small currents is not straightforward.
Epsilon 100 battery specifications : 190A discharge current continuous
To measure discharge current 190A with 0,2 A accuracy you need 0,1% accuracy !
I believe the app can only show +/- 0,2 A(resolution) and accuracy is probably even less.
The same story for original VW AGM batteries and control panel : some show 0A others always show -1A with no consumers switched on.
your estimation of discharge :
power consumption of 20 mA for the Victron SmartSolar 75/15 and 5 mA for the Eyon GPS tracker
I believe during readout with app Bluetooth increases consumption of victron MPPT.
Epsilon 100 self discharge < 3%/month =>0,1Ah/day
This adds up 0,7 Ah/day discharge.

View attachment 146498

Thanks for your reply! But that does not explain the 1-2% SOC loss per battery, according to their BMS, on heavily overcast days or when parked indoors when there is no solar charging.
So I'm still wondering what makes a California T6.1 consume more power than our previous T5.

 

[Roger Boeken]

Does your BMS tell you 1 or 2 % loss SOC or do you conclude this from the discharge current the BMS shows in the screenshot you showed before ?
What current shows the control panel of the cali ?
T6.1 is full of sensors and control units all taking a little current.
BMS itself is also using power.
But I agree, if your batteries really loose 2% SOC each every day , this is more than expected.