question

bipedalprimate avatar image
bipedalprimate asked

Node Red /VebusSetChargeState to Float, Cycles Back to Absorption

Using Venus OS Large v3.13.

Created this Node-Red flow to see if I could force "Float" to 2 MPII 48/3000/32 in parallel using the Custom Control Output Node.

1708335595933.png

Watching the LED's on MPII shows them going to Float briefly, then to Bulk then back to Absorption.

Confounding factor could be that battery is under External Control via Dbus Serial Battery from Louis Van Der Walt.

MPII Absorption & Float Voltages are the same as are configured in Dbus Serial Battery. MPII Absorption Time is set to minimum 1 hour.

The only reason to do this is to ensure that the LED's match the actual battery state - Float. Plan was to monitor Dbus Serial Battery Charge Mode and set MPII to Float when Dbus Serial Battery switches to Float.

Bulk LED corresponds to Dbus Serial Battery Charge Mode but MPII LED seems to switch to Absorption a bit earlier than Dbus Serial Battery Charge Mode.

MPII LED then never exits Absorption even when battery has fallen below Float voltage.

https://github.com/victronenergy/venus/wiki/dbus mentions that using Vebus Set Charge State to 3 will Force to Float, for 24 hours.

Couple of questions:

  1. Is what I am trying to do supposed to work?
  2. Why would MPII cycle from Float to Bulk to Absorption?
Multiplus-IINode-RED
1708335595933.png (23.4 KiB)
1 comment
2 |3000
Toggle Comment visibility. Current Visibility: Viewable by all users

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

derrick thomas avatar image derrick thomas commented ·
The battery is 'externally controlled' using dbus-serial battery driver. As such the multi will remain in 'absorption' mode (not really, but that's what it shows because it doesn't have an led for external) and listen for the driver to tell it what to do. Even though the driver might be in 'float' mode, the multi is still in 'external' mode.
0 Likes 0 ·
1 Answer
jan-bolecky avatar image
jan-bolecky answered ·

Dbus Serial probably interferes with your control i tried this, i dont have any external control only the classic ESS assistant and when i send msg to control node /VebusSetChargeState "2" it goes into absorption if i send "3" it goes to float.

2 |3000
Toggle Comment visibility. Current Visibility: Viewable by all users

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.