Daly 250A, current (amperage) reading jumping/inaccurate/inconsistent

[Lt.Dan]

This is normal behavior for most current-measuring devices when there's an inverter involved. I don't know the Daly settings but are you able to set the cutoff delay for when the max amperage is exceeded? e.g. > 150 amps for > 5 seconds or something?
I've seen the variation in Chargery, Victron Shunt (yup!), and Orion BMS (both the "instant" and "average" values), as well as some other threads on this forum about the same phenomenon. It's not noise. It's the 120HZ waveform induced into the DC system from the Inverter.

Interesting. Is there anyway to filter out this waveform from the DC side?

There is no time delay for the Daly BMS, but I have a 200a model, with the overcurrent protection set to 400a, and I've never hit it.

 

[cinergi]

Interesting. Is there anyway to filter out this waveform from the DC side?

There is no time delay for the Daly BMS, but I have a 200a model, with the overcurrent protection set to 400a, and I've never hit it.

I’m too lazy to find it lol but there’s a thread about using a low pass filter on the shunt. Hell it might be part of my build thread. Haha

 

[Martijn]

This is normal behavior for most current-measuring devices when there's an inverter involved. I don't know the Daly settings but are you able to set the cutoff delay for when the max amperage is exceeded? e.g. > 150 amps for > 5 seconds or something?
I've seen the variation in Chargery, Victron Shunt (yup!), and Orion BMS (both the "instant" and "average" values), as well as some other threads on this forum about the same phenomenon. It's not noise. It's the 120HZ waveform induced into the DC system from the Inverter.

My Victron shunt seems to work fine, very steady.

The BMS reports a widely different value every second though, not just 5-10%, just all over the place, although it seems to increase when the current is larger.

If this is 'normal', shouldn't nearly all drop in replacements in RVs suffer from this?

 

[Daddy Tanuki]

I experience the same issues but mine is even more interesting. while charging via solar and discharging via inverter at the same time my Daly tell me it is jumping from 50 amps charging to 30 amps discharging (other higher values have been as high as 100 amps charging to 40 amps discharge). intuition tells me this is a sampling rate issue... its sample rate is so slow that it jumps back and forth. My Magnum BMK (shunt based) as shown a steady draw the entire time. My Morningstar solar charge controllers charge center shows a steady charge current.

so two of them say everything is normal, and one says "i have no clue whats up and bounces back and forth like like a crack addict after trying heroin for the first time.

I put my money on the magnum and the morningstar readings. and write it off to a slow sample rate and cheesedick software. the BMS performs flawlessly other than this so I live with it.

 

[cinergi]

My Victron shunt seems to work fine, very steady.

The BMS reports a widely different value every second though, not just 5-10%, just all over the place, although it seems to increase when the current is larger.

If this is 'normal', shouldn't nearly all drop in replacements in RVs suffer from this?

Some BMSs are better than others. My Chargery saw the same size variations ... 5 amps, 60 amps, 30 amps, etc ... all over the map. Completely unreliable. The Victron varies, but not nearly as much.
drop-in batteries may/may not have the same issues - depends on the BMS they're using and the BMS configuration. I set the Chargery to delay 5 seconds before disconnecting so issues like the wild variation didn't cause problems.

 

[Martijn]

I got a firmware update with a software attempt to a fix, but the update failed several times and ended up in a completely dead BMS.

 

[Martijn]

I got a firmware update with a software attempt to a fix, but the update failed several times and ended up in a completely dead BMS.

Well, the firmware update destroyed my BMS and HEYO BMS store told me "too bad". Then after going back and forth for a bit, they told me I would get a large discount on a new purchase, I would have to tell me the order number before payment and they would adjust the amount to pay. So I did. But after I told them the order number they changed to "we'll refund you via a dispute once you ordered" ... which is a order of steps I don't really trust. Too bad.

Prices for these (Daly rebranded) BMSses went up the last few months, so I got the JK 8s BMS instead, even though that's 200A instead of the 250A Daly variant I had.

 

[john44066]

Well, the firmware update destroyed my BMS and HEYO BMS store told me "too bad". Then after going back and forth for a bit, they told me I would get a large discount on a new purchase, I would have to tell me the order number before payment and they would adjust the amount to pay. So I did. But after I told them the order number they changed to "we'll refund you via a dispute once you ordered" ... which is a order of steps I don't really trust. Too bad.

Prices for these (Daly rebranded) BMSses went up the last few months, so I got the JK 8s BMS instead, even though that's 200A instead of the 250A Daly variant I had.

What did you end up doing with that bricked BMS? I could use it for parts and would be willing to pay you for it!

 

[Martijn]

What did you end up doing with that bricked BMS? I could use it for parts and would be willing to pay you for it!

Still have it, but I'm based in The Netherlands, Europe, I thinking sending it to you would be rather costly.