I am testing/trying the settings of my new Daly 4s 250A smart BMS. So far, I found that all those end/over/under voltage protection settings work. However, I found that the errors in the discharge current reading in the PC App (Sinwealth) are large.
- No discharge current is displaced (when the battery is in fact discharging via the BMS) until the current goes above 2.3A (then the PC App jumps from 0 to 2.1A, a -10% error)
- When the discharge current is 50A, the PC App shows 51 to 52A up&down (+4% of error)
- when the discharge current is 100A, the PC App shows 107 to109A up&down (+8% of error)
I have been following up with Daly support/engineer for over a week regarding the large current reading errors and they asked me to send them videos, asked me to do the discharge current calibrations....etc and finally they asked me to do the calibration at exactly 30A discharge current. All these didn't help to lower down the error rate.
Today, it seems that they gave up and just simply replied me that 10% of error in discharge current reading is normal!
Are such large errors in discharge current reading really "NORMAL"? Is it a common problem for all brands of BMS? What were your experiences?
The primary function of the BMS is to protect the battery from being over charged or over discharged. An added value is that it can display the countdown of the "RemainingCapacity" which is calculated from the discharge current readings. When the discharge current reading has such large non-linear error, the "RemainingCapacity" displayed is not that useful.
I don't have too much hope on Daly engineers/support and am thinking installing an energy meter to count/check the Ah discharged.....but why can't this be done properly by the Daly BMS when it has such built in basic feature that I already paid?
PS Large error also occurs in the charging current readings but I don't have too much concern on this.
- No discharge current is displaced (when the battery is in fact discharging via the BMS) until the current goes above 2.3A (then the PC App jumps from 0 to 2.1A, a -10% error)
- When the discharge current is 50A, the PC App shows 51 to 52A up&down (+4% of error)
- when the discharge current is 100A, the PC App shows 107 to109A up&down (+8% of error)
I have been following up with Daly support/engineer for over a week regarding the large current reading errors and they asked me to send them videos, asked me to do the discharge current calibrations....etc and finally they asked me to do the calibration at exactly 30A discharge current. All these didn't help to lower down the error rate.
Today, it seems that they gave up and just simply replied me that 10% of error in discharge current reading is normal!
Are such large errors in discharge current reading really "NORMAL"? Is it a common problem for all brands of BMS? What were your experiences?
The primary function of the BMS is to protect the battery from being over charged or over discharged. An added value is that it can display the countdown of the "RemainingCapacity" which is calculated from the discharge current readings. When the discharge current reading has such large non-linear error, the "RemainingCapacity" displayed is not that useful.
I don't have too much hope on Daly engineers/support and am thinking installing an energy meter to count/check the Ah discharged.....but why can't this be done properly by the Daly BMS when it has such built in basic feature that I already paid?
PS Large error also occurs in the charging current readings but I don't have too much concern on this.