BMS1040A Manual Load Mode Issue (Shutdown on battery fully charged)

1 month 4 weeks ago #29535859 by Mak601
Hello,
Firmware v1.5 May 29, 2020 (Lower version same issue also).
8s Cells LiFePO4 60 Ah
If use in manual Load switch mode. (^SWMAN 2 1)
Whenever battery charge is full (cell over voltage) and BMS is cutting off the charger same moment Load cut off also (No matter !SWS is still 1).
So robot is just shutdown on the moment battery is fully charged. 
Tested on 3 items. Issue is stable and appear every time.

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1 month 4 weeks ago #29535862 by mike
I had this same issue with I think almost the exact same set up. I thought it was something to do with a cell voltage spiking as it got close to fully charged.  I ended up using a microbasic script to check the voltage on each of the cells while charging and if any exceed 3600mV, stop charging. One thing I only worked out after that I was doing wrong is under battery pack parameters and custom chemistry settings in roboBMS I was adjusting the cell high limit, but I had left the cell chemistry type on LIFEPO4 rather than custom so it probably had no effect. It may be possible to fix the issue by using the custom chemistry settings to reduce the maximum cell voltage but I haven't tested this. 

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1 month 4 weeks ago #29535863 by Mak601
Hi Mike,
I didn't tried to play with chemistry settings, but suspect same will happen.
Only way how to avoid this problem at this moment is to use this approach:
When you need to On the Load, you have to set Load switch to Automatic mode (Using script). BMS will give power to Load in this case.
When Load switch in Automatic mode, there is no sudden shutdowns on the battery full charge event.
When you need to Off Load, just switch Load to Manual mode (switch off state).
In that case when robot is On, you in Auto switch mode and no shutdown issue.
When robot is off, no matter anymore its already down. 

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