# Switch Load output MPPT SmartSolar on/off from Cerbo **URL:** \ **Category:** DIY\ **Tags:** vehicles, cerbo\_gx, victronconnect, mppt\_controllers, diy\ **Created:** [7 June 2025 08:55 UTC](https://community.victronenergy.com/t/switch-load-output-mppt-smartsolar-on-off-from-cerbo/34969 "2025-06-07T08:55:14Z")\ **Posts on this page:** 9\ **Page:** 1
**Author:** ![HPHeuer](https://dub1.discourse-cdn.com/victron/user_avatar/community.victronenergy.com/hpheuer/32/8671_2.png) [@HPHeuer](https://community.victronenergy.com/u/HPHeuer)\ **Post date:** [7 June 2025 08:55 UTC](https://community.victronenergy.com/t/switch-load-output-mppt-smartsolar-on-off-from-cerbo/34969/1 "2025-06-07T08:55:14Z")
Since there is no “manual mode”-option for the Load output of the MPP 100/20, it seems that I can’t turn it on/off by software. Any solution? I’ve already tried all the operation modes, to disable VictronConnect control. ---
**Author:** ![Les](https://avatars.discourse-cdn.com/v4/letter/l/db5fbb/32.png) [@Les](https://community.victronenergy.com/u/Les)\ **Post date:** [7 June 2025 11:09 UTC](https://community.victronenergy.com/t/switch-load-output-mppt-smartsolar-on-off-from-cerbo/34969/2 "2025-06-07T11:09:48Z")
Will toggling between always on and always off not work? I do not have any loads connected to my unit but I just took a peak at my units output settings on Victron Connect and that appears as though it would work? ---
**Author:** ![HPHeuer](https://dub1.discourse-cdn.com/victron/user_avatar/community.victronenergy.com/hpheuer/32/8671_2.png) [@HPHeuer](https://community.victronenergy.com/u/HPHeuer)\ **Post date:** [7 June 2025 11:23 UTC](https://community.victronenergy.com/t/switch-load-output-mppt-smartsolar-on-off-from-cerbo/34969/3 "2025-06-07T11:23:04Z")
I need to switch by software, depending on some condtion, which I can request from another Victron device ---
**Author:** ![Les](https://avatars.discourse-cdn.com/v4/letter/l/db5fbb/32.png) [@Les](https://community.victronenergy.com/u/Les)\ **Post date:** [7 June 2025 11:34 UTC](https://community.victronenergy.com/t/switch-load-output-mppt-smartsolar-on-off-from-cerbo/34969/4 "2025-06-07T11:34:31Z")
Ahhh. Sorry, I misunderstood your question ---
**Author:** ![HPHeuer](https://dub1.discourse-cdn.com/victron/user_avatar/community.victronenergy.com/hpheuer/32/8671_2.png) [@HPHeuer](https://community.victronenergy.com/u/HPHeuer)\ **Post date:** [7 June 2025 16:54 UTC](https://community.victronenergy.com/t/switch-load-output-mppt-smartsolar-on-off-from-cerbo/34969/5 "2025-06-07T16:54:12Z")
So far, I tried everything, but there seems to be no way to control the load output from the Cerbo. The MPPT 100/20 attribute “/load/state” is read-only. Any workaround? Why would this be important in an RV? If you use the load output to trickle charge the starter battery (via Votronic Standby Charger), problems come up, when you start the engine: The alternator would start ot charge the the RV battery with 14.2v (via Orion XS). This would partially go back to the trickle Charger, and then you have a loop. Maybe not fatal, but not nice. The D+ signal should turn off the load output of the MPPT. And this seems to be impossible… I don’t like the idea to buy a Votronic Standby-Charger PRO and wire some cables, when it could be done by software. ---
**Author:** ![Les](https://avatars.discourse-cdn.com/v4/letter/l/db5fbb/32.png) [@Les](https://community.victronenergy.com/u/Les)\ **Post date:** [7 June 2025 18:21 UTC](https://community.victronenergy.com/t/switch-load-output-mppt-smartsolar-on-off-from-cerbo/34969/6 "2025-06-07T18:21:43Z")
Could you put a diode in the charge circuit to prevent back feed. I’m still not sure I fully understand if you are looking for an automated system or a system that you can manually control remotely? When you state that the load state is read only are you talking about VRM or Remote Console or Victron connect? There are differing levels of control available in each. In Victron Connect - Devices you can definitely control the output manually but there are only pre-defined logic options for automatic switching ---
**Author:** ![HPHeuer](https://dub1.discourse-cdn.com/victron/user_avatar/community.victronenergy.com/hpheuer/32/8671_2.png) [@HPHeuer](https://community.victronenergy.com/u/HPHeuer)\ **Post date:** [7 June 2025 19:14 UTC](https://community.victronenergy.com/t/switch-load-output-mppt-smartsolar-on-off-from-cerbo/34969/7 "2025-06-07T19:14:58Z")
The load output should be turned on and off fully automated, depending on conditions (alternator running or not). The /Load/State is read only with d-bus commands from the console and from node-red. Manual switching with VRM or VictronConnect is no problem. In VictronConnect I tried all configurations for the load output, but still not writable. There is already a diode in place to prevent back feed. But things are more complicated with modern alternators, which have changeing voltage depending on demand AND an Orion XS is controlling alternator power for the RV-battery, which is connected to the MPPT and the load output. Situation (there are more): - Orion XS is in bulk mode, output 14.2V to the RV-battery. - The smart alternator from the engine changes voltage to 12.8V (or much less) - The load output from the MPPT tries to trickle-charge (I have a 4 Amp delimiter) the engine starter battery with 13.5V (0.7V less because of the diode) - this is a bad loop! - Now the engine electronic is totally confused about the unknown source of electrical power and may try to regulate the alternator. - It’s good luck, when the alternator controlling system of the engine stays calm Therefore: when the engine (alternator) is running, this trickle-charging needs to be turned off. The same applies with shore power-charger and engine running. Votronic has the StandBy Charger Pro with a special disable input (they know about the problem!). But I don’t like to add a black box to my wonderful blue boxes. Isn’t there any Software solution? ---
**Author:** ![HPHeuer](https://dub1.discourse-cdn.com/victron/user_avatar/community.victronenergy.com/hpheuer/32/8671_2.png) [@HPHeuer](https://community.victronenergy.com/u/HPHeuer)\ **Post date:** [15 June 2025 14:48 UTC](https://community.victronenergy.com/t/switch-load-output-mppt-smartsolar-on-off-from-cerbo/34969/8 "2025-06-15T14:48:46Z")
With the help of the AI “Claude” (Claude.ai) I found a solution to control the load output: My MPPT is connected via VE.Direct and a USB-Adapter (USB2) to the Cerbo. Sending the Hex-code for the load operating modes over the VE.Direct-bus does the job: # always on echo -e “:8ABED0000B5\r” \> /dev/ttyUSB2 # always off echo -e “:8ABED0004B1\r” \> /dev/ttyUSB2 … # user defined algorithm 2 echo -e “:8ABED0006AF\r” \> /dev/ttyUSB2 ---
**Author:** ![system](https://europe1.discourse-cdn.com/victron/original/1X/21a9a7b5db7c6339715f993568736a7053199995.png) [@system](https://community.victronenergy.com/u/system)\ **Post date:** [29 June 2025 14:49 UTC](https://community.victronenergy.com/t/switch-load-output-mppt-smartsolar-on-off-from-cerbo/34969/9 "2025-06-29T14:49:36Z")
Closed on 29 June 2025 14:49 UTC This topic was automatically closed 14 days after the last reply. New replies are no longer allowed.