question

Hi there. Yes, SPS (not SBS) mode is a new operating mode for the batteries - and we're all learning the ropes in terms of implications for associated energy systems.

In terms of the 'Low Battery Alarm', there are a few aspects of the answer to your question - with apologies for this reply being fairly long as a result.

By default the BMS only sends the SoC value for batteries in the normal 'run' mode, and that calculation doesn't include batteries in SPS mode.

You can include SPS-mode batteries in the SoC calculation with a setting change on the BMS:

Go to the 'Configuration->CANBus' page on the BMS and change the drop-down setting called "State of Charge" to be "State of Charge (SPS)" instead of the default "State of charge(all)" ( see screen shot below).

This will result in the SoC sent by the BMS, and reported by the GX, now including the SPS batteries. So the SoC will show up as 'more than 0%' - and (in your site) will then be 'what you expect'.

Ok, while that's good - unfortunately it will not actually remove the Low Battery Alarm being reported to VRM by the GX system.

That's because the Low Battery Alarm report is not based on SoC. Instead, it is generated based on DC bus voltage being low. As well as when SPS is enabled, this issue (undesired Low Battery alarms) also occurs on a single-battery Redflow site when that battery is performing its periodic maintenance cycle.

Now lets look at that Low Battery alarm in a bit more detail. It turns out that it is evaluated and reported independently in two distinct places in an overall Victron Energy system.

The first place it is evaluated and reported is on the screen of the GX directly. The GX will pop up a Low Battery alarm when the DC voltage falls away. This on-screen GX alarm can be disabled, (and with Redflow batteries, it should be).

The instructions to disable this on-screen GX low battery alarm are included in the standard Redflow integration advice here:

https://redflow.zendesk.com/hc/en-us/articles/360025202052-Installation-guide-to-connecting-a-Redflow-battery-array-to-a-Victron-Energy-system

The second place a Low Battery alarm shows up - as you have noted - is in VRM, where it is bundled up with a lot of other alarms you will want to know about.

Unfortunately the Low Battery alarm reported by VRM is not suppressed when the on-the-GX alarm is turned off... and in general there is no apparent way (that I have found!) to disable the VRM's version of the Low Battery alarm.

.

Perhaps someone from Victron could comment on whether they might be able to change the VRM portal code so that if the Low Battery Alarm is disabled on the GX, then that alarm is not reported on the VRM portal.

That would seem to be a logical and reasonable way to operate here... i.e. as a general statement about alarms ... if a given alarm is disabled directly on the GX, I would think it would be both logical and useful for that alarm type to not be reported up to the VRM portal.

In this regard (alarm reporting) - I feel that consistency would seem to be a good thing in general -i.e. I think it'd be great if the VRM portal only reported alarms that are enabled on the GX itself, and didn't report alarms that have been directly disabled on the GX.

Regards,

Simon Hackett

(for Redflow)