question

Simon Coram avatar image
Simon Coram asked

Excess solar diverting

I’ve just fitted a Cerbo GX to my boat. My set up is 780w solar panels, 100/50 Victron MPPT, multiplus inverter which hardly gets used as the boat is mainly a 12v set up and a smart BMV 712..

I’ve fitted a 300w 12v element to my hot water tank which works well, it’s wired in by a manual switch that I have to switch on and off.

is there a way of getting any excess solar load to heat the water when the batteries are at 100%.

Possibably to be able to trigger it remotely via the cerbo when we are going to the boat to arrive to a tank of hot water.

Thanks

MPPT Controllerscerbo gxHot Water Diversion
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.

Rob Duthie avatar image Rob Duthie commented ·
Hi

As per Kevin Windrem post, this is what i do and it works perfectly using the relay assistant.

1) Use primary programmble relay

2) Set relay off

3) when SOC lower than 95%

Regards

Rob D

NZ

1 Like 1 ·
5 Answers
Simon Coram avatar image
Simon Coram answered ·

Bringing this back up.
Does anyone have any ide?


Thanks.

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.

Kevin Windrem avatar image
Kevin Windrem answered ·

The hard part would be determining if the solar panels could power the heater. Once the batteries ready 100%, the solar current will drop to zero since there is no where for the power to go.

You could use a relay assistant in the Multi to activate at 100% SOC and deactivate at say 95% SOC. So if there's no solar you'd drain off 5% SOC but then the heater would turn off.

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.

Alexandra avatar image
Alexandra answered ·

@Simon Coram

This post has some interesting thoughts on using the bmv.

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.

Rob Duthie avatar image
Rob Duthie answered ·

Hi All

Up date on the Victron Multiplus aux relay for a hot water diverter or other loads at SOC setting. using the Aux relay assistant. Test to date OK 10/12/2022. in the past this did not work that well? updated assistant may be?

Note: i used a lo-ran wireless link to make the connection.

programmable relay (size:30)

*) Use primary programmable relay.

*) Set relay on

*) when SOCHigher than 100%.


programmable relay (size:30) 1

*) Use primary programmable relay.

*) Set relay off

*) when SOClower than 98%.


Regards

Rob Duthie

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.

Kevin Young avatar image
Kevin Young answered ·

Hi,
I'm relatively new to Victron kit but am trying to do something similar (I think!)

I have 48V boat installation with 10kW Quattro, 3kW PV (3 x 150/35 Mppts), MG 1120Ah Li-Ion bank, plus Genset, all connected via CerboGX set to use DVCC & VRM access. I'd like to use excess solar to heat water via immersion heater (on Quattro AC2-Out ??) when SoC is >99%. I have all latest firmware (using 'Sustain' mode on Quattro) and MK3-USB.

I'm trying to learn how to best setup/configure the logic to acheive this. Where to read and use the SoC info to switch the AC2 out relay? etc Currently using one relay in CerboGX to auto-start generator. Any help very welcome!

Tia

Kev


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.