question

terbonium avatar image
terbonium asked

Charge Current Limit does not compensate for DC Loads when charge from Generator/Grid.

When charging from the generator-AC1(battery saver selected) or grid-AC2(keep batteries charged) the ESS profile attempts to charge the batteries to 100%. It honors the BMS restrictions of Charge Voltage/Current limits. As the lithium batteries reach 100% the BMS CCL approaches 0. When charge power is coming from an AC source the charge current from the Quattro matches the Charge Current limit, however it does not compensate for additional DC loads. ie, CCL=20A, DC Loads=14A, the resulting charge current is 6A. However, when charging strictly from solar via MPPT controllers, CCL=10A, DCLoads=6A, SolarYield=16A.


The compensation for the Solar/DC Loads only happened recently. Does this need to be added to the AC Charger as well?

ESS
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2 Answers
mvader (Victron Energy) avatar image
mvader (Victron Energy) answered ·

Hi @terbonium, correct: the GX Devices do not compensate for DC loads when applying the charge current limits. Leading to the system charging with less current than its allowed to.

This is a limitation of the implementation, and I'm afraid that it might take quite some time before we get around to fix this.

I did add it to the manual: https://www.victronenergy.com/live/ccgx:start, then go to chapter 4.4 and see Particular #3, about about DC loads.

My apologies that this was not in the manual yet.

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terbonium avatar image
terbonium answered ·

Thank you for the answer. Can you confirm that it appears the solar controllers compensate for the DC loads?


Here is what my system looks like after the bank has charged. What's interesting here is that the solar controllers are applying about 8A( 105W ) (full sun is available at the time, charge current could be as high as 60A). DC loads are 113W, CCL is 1.1A( 14W ) It appears the system is trying to balance the DC loads.



screen-shot-2019-06-20-at-44744-pm.png (170.0 KiB)
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