question

markok12345 avatar image
markok12345 asked

AC charge current adjustment

What options I have adjust Multiplus 2 AC charging current? Is it possible to do with MQTT or API request? I think that one option is do this programming AUX port to this use using 0-5V signal. If I use this method can I use 1kHz PWM signal or must it be pure DC?

battery charging
2 |3000

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

6 Answers
Mike Dorsett avatar image
Mike Dorsett answered ·

This can be done with a hex protocol request via the VE-bus communications,

Command:
Reply:
‘S’ <Switch state> <Pot value> <Panel scale> 0x01 <Flags>
‘S’

Where the pot value changes the AC current.

Other methods may be possible.

2 |3000

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

markok12345 avatar image
markok12345 answered ·

Thank you for your answer. If I use AUX input and voltage adjustment to adjust charging current so can I use PWM signal? How much it needs current from controlling supply device?

2 |3000

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

sharpener avatar image
sharpener answered ·

It has a high input impedance but there is a 10 kohm pull-up resistor to +5V, see the pictures in this thread.

2 |3000

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

markok12345 avatar image
markok12345 answered ·

I checked the link. Have I understood right that Victron supply +5VDC itself and I must use potentiometer between AUX pins? I mean that I can't use external power supply and give 0-5VDC to Victron?

2 comments
2 |3000

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

markok12345 avatar image markok12345 commented ·
Maybe I understood wrong when I watched first time picture what you linked. When I read it again I think that I can use external power supply too.
0 Likes 0 ·
Show more comments
markok12345 avatar image
markok12345 answered ·

I tried do this today but I can't do it correctly. I configured assistant to AUX port using MK3 and VEconfiguration software. Then I sent parameters to Multiplus 2 GX and everything seems to be ok. When I tried change voltage to AUX port between 0-5VDC so nothing happens. What I have done wrong? Must I activate assistant somewhere or do other jobs?

1 comment
2 |3000

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

markok12345 avatar image markok12345 commented ·
Now it work well, but I don't know what was wrong. Previously charger was "bulk" mode and I can't adjust charge current. Then something happened and charger status change to "off". Now I can adjust charging current.
0 Likes 0 ·
hominidae avatar image
hominidae answered ·

...you can do that with MQTT, easily (if you have a GX or Rpi with VenusOS running)....I am using it all the time.

The topic in question is N/<your VRM ID here>/settings/0/Settings/SystemSetup/MaxChargeCurrent

Set it to value: -1 when you want the setting to be off (current limited by the MP2 and/or BMS reported limit)...set it to value: X , where X is the max current in DC Amps to be allowed to charge with.

remember, that the topics starting wih N/... are for reading...change a value by publishing to the corresponding W/<your topic> , so in this case:

W/<your VRM ID here>/settings/0/Settings/SystemSetup/MaxChargeCurrent

see the dbus documentation for details on how to enable mqtt on the GX

2 |3000

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