Aili battery monitor resets to 100% when battery shuts off (dies)

[CamGuerilla]

When my LiFePO4 batteries go too low, the BMS shuts them off. As you would expect. But when that happens, my Aili battery monitor resets to showing 100% full. At this moment, the batteries are, of course, at basically 0% so the monitor is inaccurate until the point when the batteries are once again actually charged to 100%

Is there any way to prevent this from happening besides not letting the batteries discharge to the shut-off point?

 

[sunshine_eggo]

If there is, it would be in the manual.

The Victron shunts behave the same way by default. One has to disable the "starts synchronized" feature. When disabled, "---" is displayed until the unit syncs again OR you manually enter a SoC.

Can the Aili be programmed manually - an arbitrary SoC you can enter?

Best option moving forward in any case is to ensure the battery never gets so low the BMS has to cut it off.

 

[timselectric]

Pretty simple solution.
Don't let the battery go that low.

I told the doctor that it hurts when I do this.
The doctor said "well, stop doing that ".
It hasn't hurt since.

 

[chrisski]

When my LiFePO4 batteries go too low, the BMS shuts them off. As you would expect. But when that happens, my Aili battery monitor resets to showing 100% full. At this moment, the batteries are, of course, at basically 0% so the monitor is inaccurate until the point when the batteries are once again actually charged to 100%

Is there any way to prevent this from happening besides not letting the batteries discharge to the shut-off point?

I have the Ali shunt on a solar generator and have twice had my batteries drain so much the BMS shuts the off. The Ali shunt has no power to it, so it has no display. I don’t understand why your Ali display shows 100% If the BMS has tripped the batteries. I can only guess is because it is still light out and the SCC is delivering power with little load, which doesn’t make sense because my Ali shunt tracks amps in and amps out, not charge state based off voltage.

I have found my batteries discharged on cloudy days after returning at night with no display, and I left them hooked up without a load to charge the next day, that I came back and the batteries were at 100% after a good day of charging.

Pretty simple solution.
Don't let the battery go that low.

A former president once said their are simple solutions, but not easy solutions.

As in my case, I use the cheap Daly low amperage BMS to cook in a crock pot while I’m at work. If the weather says it will be good in an area where there’s not a clue in the sky 300 days a year, I expect my 900 watts of panels to deliver enough power for the 230 watt load. Usually they do, but sometimes the weather is cloudy, or I’m held at work after sunset. Can’t really help those if I’m gone all day and want to use this solar stuff ‘I spend so much time on.

 

[timselectric]

I have the Ali shunt on a solar generator and have twice had my batteries drain so much the BMS shuts the off. The Ali shunt has no power to it, so it has no display. I don’t understand why your Ali display shows 100% If the BMS has tripped the batteries. I can only guess is because it is still light out and the SCC is delivering power with little load, which doesn’t make sense because my Ali shunt tracks amps in and amps out, not charge state based off voltage.

If I'm reading between the lines correctly.
Their shunt resets to 100% on power up. (After shutting down)

 

[CamGuerilla]

If there is, it would be in the manual.

The Victron shunts behave the same way by default. One has to disable the "starts synchronized" feature. When disabled, "---" is displayed until the unit syncs again OR you manually enter a SoC.

Can the Aili be programmed manually - an arbitrary SoC you can enter?

Best option moving forward in any case is to ensure the battery never gets so low the BMS has to cut it off.

Thanks Sunshine... I don't think you can enter an arbitrary SOC. The desired behaviour would be for it to remember the SOC when the battery went offline and then start at that point once the battery is being charged again.

 

[CamGuerilla]

If I'm reading between the lines correctly.
Their shunt resets to 100% on power up. (After shutting down)

exactly.

 

[CamGuerilla]

Pretty simple solution.
Don't let the battery go that low.

I told the doctor that it hurts when I do this.
The doctor said "well, stop doing that ".
It hasn't hurt since.

Thanks for taking a moment to reply Tim. I understand that this is a legitimate option as mentioned in my original question. when I said "besides not letting the batteries discharge to the shut-off point" However, I was wondering if the monitor could be made to remember the SOC at the point of the battery going offline so that when the battery comes back online it would start again at that point. The monitor does have some sort of persistent memory because I've set the "battery full" parameter to 200Ah and when it comes back online again, it is still set to 200 Ah. It would be nice if it could use that same memory to store the SOC at the moment it goes offline. However, I have not found anything in the manual to indicate that. I thought someone here may have found a hidden option of some sort.

 

[timselectric]

Thanks for taking a moment to reply Tim. I understand that this is a legitimate option as mentioned in my original question. when I said "besides not letting the batteries discharge to the shut-off point" However, I was wondering if the monitor could be made to remember the SOC at the point of the battery going offline so that when the battery comes back online it would start again at that point. The monitor does have some sort of persistent memory because I've set the "battery full" parameter to 200Ah and when it comes back online again, it is still set to 200 Ah. It would be nice if it could use that same memory to store the SOC at the moment it goes offline. However, I have not found anything in the manual to indicate that. I thought someone here may have found a hidden option of some sort.

I doubt that it's an option. As far as memory. It's much easier to remember a setting, than it is to monitor a moving target. And remember what it was right before the power is lost. The same power that is needed to write the data into memory.
But, I will wish you good luck.

 

[CamGuerilla]

I doubt that it's an option. As far as memory. It's much easier to remember a setting, than it is to monitor a moving target. And remember what it was right before the power is lost. The same power that is needed to write the data into memory.
But, I will wish you good luck.

Oh at this point I'm no longer looking for a fix. It's just a limitation of the unit. As far as writing to memory, an update every minute or so would probably be sufficient. Not looking for pinpoint accuracy. Would only be a problem if it was updating the moment the power went off.
Oh well... on to the next thing. ;-)

 

[chrisski]

If I'm reading between the lines correctly.
Their shunt resets to 100% on power up. (After shutting down)

That could be. I’ve never been able to watch it recharge to see if it does that.

 

[timselectric]

That could be. I’ve never been able to watch it recharge to see if it does that.

Not during charging.
It defaults to 100% on first power up.
Every time the BMS shuts down, the shunt has no power. When power is restored, the shunt is experiencing a first power up.

 

[chrisski]

Not during charging.
It defaults to 100% on first power up.
Every time the BMS shuts down, the shunt has no power. When power is restored, the shunt is experiencing a first power up.

I never noticed that with the AiLi shunt. Nice to know.

 

[timselectric]

I never noticed that with the AiLi shunt. Nice to know.

This function can be disabled on Victron shunts.
Not sure if it is an option for the ali ones.