Kilovault hlx+ for UPS

[65NW]

Repurposed my kilovaults for a on grid ups/backup for home heating system.
Doing wiring, sitting here and just realized that with no current on them, they are going to shut off and will not be available when the lights go out and the victron multiplus ii tries to pick up the load.
Any thoughts? (Besides predicting when the power goes out by 30 seconds, I already thought of that!)

While we are at it, what exactly does the CAN port on the KVs do? It doesn't talk with victron as per kV support and they never (as far as I can tell) finished making the hlx bridge for pack balancing.

Can a "keep alive" message be sent over CAN?

Probably not the right batteries for this task...

 

[65NW]

as expected, the kilovault hlx's shut off after reaching full charge off the charger/inverter. once ac power is lost, they do not come back on. the only way to turn them on is push the button on each battery.
used my multiplus on another system and pulled an old growatt 3k out for this. same thing...

"would be nice" features.
1) a toggle/setting in kilovault app that keeps batteries on when they are above x% SOC. like "when above 90% SOC: stay on"
2) CAN message from an external controller to stay on
3) external contacts which power a fet or relay to keep bms powered up.

since those dont exist, I though of a few work around but will probably not implement any.
1) put inverter in solar,battery,grid priority setting where it basically cycles the pack using AC power (and recharge) when soc hits a low point, then runs off battery until it returns to the charge point. great way to use up battery life...
2) ac timer: every 30-60 minutes, turn off the ac power to the charger and force it into UPS mode for a few seconds/minutes. this would not use much battery life but will shorten the life of the contactors/relays in the inverter/charger which I hear clicking every time this transfer happens.
3) dc load timer: set the battery charge current to be very low, then every 30-60 minutes, turn on a large dc load to pull the dc bus down. forces the batteries into discharge for a few moments before they go back into charge, then standby.

these are all rather silly workarounds. probably will be getting some lead acids for this and deal with off gassing in a boiler room.

I have had the HLX+'s shut off in this same way under certain lighting conditions when they were my primary solar batteries. came home several times to a cold house after the BMS's saw no load (provided all loads from the MPPT for several hours) and then went to deep sleep. had to push buttons to get them back on. not thrilled about this aspect of the HLX+'s.

 

[65NW]

Update.
Got it working, kind of.



-Switched the Multiplus out for a 24v 3kw growwatt.
-Running the growwatt disconnected from grid.
-Using a drok ac to DC converter to charge/run the batteries. This is the key.

The drok allows me to set charge current so it it just below peak demand. When the boiler fires, it briefly pulls 9A, which is more than the drok supplies (8A). This pulls 1A from the batteries every 30 min and keeps them from going into hibernation mode. They spend 98 pct of the time in standby, 1pct in discharge and 1pct in charge. So far they have never shut off all the way. Even had a short power outage during a snow storm the other day and it never even knew.

The two Kilovault hlx+ 1200s in series runs boiler, circ pumps, zone valves and radiator unit for just over 12 hours at -15F outside. plenty long to get a generator setup and keep the house warm.

 

[65NW]

Its basically space bar heating the BMS. ?

Workflow

xkcd.com