Battery voltage sense fault?

[jmktexas]

Finally got radian up and running and all panels are up. Had a strange event occur. “Battery voltage sense fault” then one second later “battery voltage sense ok”. Not sure what that means. Batteries had charged to 100% and had minimal load maybe .3 kw. Do I need to be worrying about something or is this some lifepo battery thing? Manual says this event means battery was under 8v or over 72v. Pretty sure that hasn’t happened.

[mahendra]

I had the same even today .
Was looking at the forum for an answer but found none

[mahendra]

I noticed you experience this since in March.
Did this reoccur?

[jmktexas]

No I’m pretty sure that problem is a battery bms issue. I added another battery and that problem went away. If I recall you have a bunch of those eg4ll batteries too. Their bms has issues, in my opinion. I only live about 25 miles from signature and I know some of them personally. They are not bad/crooked folks but their stuff is mostly entry level and they don’t/can’t do hybrid inverter systems. At least at from my last conversation with them. Entry level may be too harsh but it ain’t Outback. If you pile enough batteries on the eg4ll can handle what we need, but did we save any money?

I’ve moved on to different problems

[mahendra]

Yes. True I swapped out their bms with some overkill solar bms .
But I am still not satisfied with the performance.
I am now thinking that their cells have issues too.
I did other outback systems (vfx ,other radians )with overkill solar bms but haven't had these issues.
Just to share the other cells are Calb,Eve ,Rept and Catl.

[jmktexas]

I’m not smart enough to change out bms. Wouldn’t even try. But I did talk to the guy that owns signature today and he agreed (sort of) that the bms was way “conservative “ for what I was doing. My response was “specs are specs right?”

The batteries themselves seem to perform properly to me. The bms seems to shut everything down too quickly. Certainly not smart enough to know how to fix that. Bms simply will not take a surge it is rated for.

Hey but they were cheap right!

[mahendra]

That's is true .
Upon removing the bms built looks great but I am suspecting as other have identified its a software issue.
When I mentioned the performance I was comparing to other cell within the same price range.
The cells seem to be out of balance and I don't think the SS bms nor the overkill can compensate for it JK bms seem to be the best solution for SS bms.
The problem is outside I'd SS reach since all of this is coming out of China.
I miss admitted its still not a bad buy

[Ampster]

I use a 2 Amp JK Active Balancer on a 42 kWh pack of EVE cells. It has worked well. I also have the Overkill BMS on some smaller pack and it just took longer for the cells to be balanced.

[carman3]

Just adding another experience to this thread..

I've had issues with battery sense on a new install testing two different Radian units. The firmware was updated immediately upon installation so we're not sure if the issue occurred on the older firmware.

Both inverters intermittently exhibited the Battery Sense fault, as we swapped the two in testing, with barely any load on the system (400W load on 8048A). If we factory reset the units, they do NOT exhibit the issue. It was only after the "Low Battery", "High Battery" and "Battery Charger" settings on the Radian was adjusted to handle LFP batteries that the unit drops the output load and displays the Battery Sense error.

Support was less than helpful however, with a lot of trial and error, I've come to some conclusions.
1. There is something in those three above settings that the Radian does not like. The unit can be on AC power (Grid) or battery when it drops output and then pulls a load on the batteries like the inverter was just powered off and back on.
2. The battery sense fault is a poor description. The batteries are not causing the error. The Radian is dumping the capacitors to the output load. The unit then 'recharges' the capacitors like its initially powered on again which pulls the startup inrush current from the battery to which the Mate3 reports as a 'Battery Sense fault'.
3. If we factory reset a Radian and changed only the low battery cutoff (raising it for LFP batteries) the unit would exhibit the issue at random times. We're trying variations of settings now between battery charger and Low Battery Cutoff to see what combination we can find to make the unit stable.

I mention the Low Battery Cutoff, but the batteries never drop below 51v unless the startup current is drawn so that setting should be irrelevant. I read on a previous post someone mentioned 'fragile' settings for which support is unaware of the interactions with each other and from my limited experience troubleshooting this issue, that is exactly my experience as well.

[raysun]

2. The battery sense fault is a poor description. The batteries are not causing the error. The Radian is dumping the capacitors to the output load.The unit then 'recharges' the capacitors like its initially powered on again which pulls the startup inrush current from the battery to which the Mate3 reports as a 'Battery Sense fault'.

I'm curious, how is the capacitor discharge and recharge being measured?

[mahendra]

Just adding another experience to this thread..

I've had issues with battery sense on a new install testing two different Radian units. The firmware was updated immediately upon installation so we're not sure if the issue occurred on the older firmware.

Both inverters intermittently exhibited the Battery Sense fault, as we swapped the two in testing, with barely any load on the system (400W load on 8048A). If we factory reset the units, they do NOT exhibit the issue. It was only after the "Low Battery", "High Battery" and "Battery Charger" settings on the Radian was adjusted to handle LFP batteries that the unit drops the output load and displays the Battery Sense error.

Support was less than helpful however, with a lot of trial and error, I've come to some conclusions.
1. There is something in those three above settings that the Radian does not like. The unit can be on AC power (Grid) or battery when it drops output and then pulls a load on the batteries like the inverter was just powered off and back on.
2. The battery sense fault is a poor description. The batteries are not causing the error. The Radian is dumping the capacitors to the output load. The unit then 'recharges' the capacitors like its initially powered on again which pulls the startup inrush current from the battery to which the Mate3 reports as a 'Battery Sense fault'.
3. If we factory reset a Radian and changed only the low battery cutoff (raising it for LFP batteries) the unit would exhibit the issue at random times. We're trying variations of settings now between battery charger and Low Battery Cutoff to see what combination we can find to make the unit stable.

I mention the Low Battery Cutoff, but the batteries never drop below 51v unless the startup current is drawn so that setting should be irrelevant. I read on a previous post someone mentioned 'fragile' settings for which support is unaware of the interactions with each other and from my limited experience troubleshooting this issue, that is exactly my experience as well.

Hi it would be nice to know if you have an update on what caused the battery voltage sense fault
Old firmware or the setting you mentioned