Daly BMS gone crazy..Update Opinions

Here's some steps we took to get our Daly BMS working much more efficiently that may prove helpful to some.

We purchased a 200a Daly Smart BMS 4s about 3 mo. ago (Mar 2021 production date). Discovered very quickly a large number of factory presets must be adjusted and calibrated to enable the Daly to generate much more accurate current/voltage (and SOC) data. Accurate voltage/current data is essential to effectively protect your cells. Unfortunately, the Smart BMS BT app only offers very limited capability in terms of adjustments & calibrations, so Sinowealth (Windows app) must be used.

Highly recommend calibrating the voltage. Our Daly was reading almost .1v low. Not good. Hard to believe, but our Daly was also displaying discharge current as charge current and vice versa. The polarity was reversed. This caused dramatic voltage drops and heat (MOSFETS subjected to reverse current). We corrected this by calibrating the Work Current with the proper polarity. This can be done using either a known load value or clamp-on ammeter (calibrations be accomplished using either charge or discharge current). As for SOC, the low-voltage discharge cut-off and high-voltage charge cut-off values determine the zero and 100% SOC set-points and work hand-in-hand with the Voltage Capacity values. Voltage Capacity values for 10-100% SOC must adjusted significantly different from Daly's default values. You *must* charge to 100% SOC and discharge to the low-voltage cut-off at least two times in order for the SOC meter to establish accurate set points. Another critical adjustment to get the SOC and current readouts to display accurately is the proper adjustment of the Dfitter current. This value should be adjusted to the lowest value possible (ideally <=100mv) without incurring random readouts under zero load conditions. A zero load calibration must be accomplished after every dfitter adjustment. If the dfitter and zero load values are not adjusted properly it will effect both the realtime current readout (especially at lower power levels) and skew the SOC readouts significantly over time. Lastly, make absolutely sure when you're doing any current calibrations that you use (-) neg values for discharge and (+) pos values for charge.

After quite a bit of trial and error we finally got all these preset values dialed in. Our BT Smart BMS SOC display is now very accurate. Current readouts are accurate down to .1v. Important since erroneous current readings can skew the SOC readout very quickly. We also purposely exceeded the most important voltage, current, and temperature thresholds to verify all BMS protections are operating at their proper values. All is good.

If you're willing to take the time to get all these values dialed in, IMO the Daly has the potential to be an awesome BMS that will offer excellent protection and operate at its rated maximum current with minimal heat output. If you're wanting more of a plug & play experience, I would definitely not recommend a Daly--lol!