How did the CADC get changed?
What is CADC?
CADC Gain =
Current
Amps
Direct
Current Gain.
The BMS has a built in shunt for metering both current and for tracking AH in/out of the battery. Shunts need to be calibrated.
There is another calibration parameter called CADC Offset.
Y=Mx+B. In this case CADC Gain = M and CADC Offset = B. Plug in (typically 50 or 100 mv) reading from the shunt (x) and you calculate for actual amps
If CADC Gain is inverse, then discharging (positive Y) and charging (negative Y) are seen backwards; in other words, the BMS was set to limit current to 100a during charging, however since this number was reversed, and he was discharging, the BMS was trying to hold back current.
Thanks to Dexter at currentconnected.com for his help
Even though I ended up not needing the replacement, good to know currentconnected stands behind what they sell.
It truly was a pleasure to have you as our customer, because you really wanted to work with me to find the root cause. You helped us improve our process, solve the problem and now we can prevent any other customer from experiencing the frustration you had.
To bring everyone up to speed; we were told these units were all coming identically programmed and individually calibrated from the factory, which has proven not to be the case. From now on, we are serializing, testing, and tracking each and every BMS unit that we touch. We are also verifying calibration with 6 1/2 digit NIST certified equipment. We are also now checking every single parameter in the configuration because we cannot have issues like what OP experienced, it isn't good for business. If it takes an extra 20 minutes per BMS, then great. It saves 2 days of troubleshooting, and then the customer is out of a BMS and has to delay their project which is unacceptable practice for our company.
Continuing on, Daly has a reputation for these types of programming issues, so we should have already been checking everything that we are now...My fault. Lesson learned. I know Daly has BEEFY bms units, that really can take some abuse, I've taken them apart. I've run over 400a through a 200a BMS MULTIPLE times without damage or issues. However, a negative sign is causing a dumb issue as we've seen in this thread and ruining the daly brand.
If what it takes to sell a good product is the final QC I listed above, then I absolutely will do it without question, everytime. It's worth it when things arrive at a customer's house in GOOD WORKING ORDER AND PROPERLY PROGRAMMED, so then the customer can carry on with building their projects.
I can't drive home any further that our business is not about just selling a part (in this case a BMS). We are selling my customers solutions, and if a BMS arrives and is not properly functioning, we have failed at our job. No matter what it takes,
@OTRwSolar bought an "all inclusive kit" from us, we owe him exactly that; a properly functioning and designed, all inclusive kit!
EDIT: This BMS that experienced issues is still covered by my warranty - If any issues arise, we will replace it, no questions asked. We already shipped a replacement but OP returned it to us because the original wasn't appearing defective after he fixed the CADC gain...But even then, if we have to ship another replacement, we STILL take care of our customers.
