Battle Born Charging
This might answer some recent questions. The table is not accurate wrt to the BB comments--don't go by it by the table itself. Wade through the questions and answers to get the true picture. Tak...
Forum Discussion
BFL13 wrote:
Itinerant1, ISTR, said he has been operating for four years, but does not know what his battery capacity is. That makes sense. It will be lower with age/use as he has said. I wondered in that case where he got that 99% from, but he got mad when I asked that. Apparently his BMS is not the same as a BB's BMS so he can use his for that somehow. I got lost with the BMS business.
I didn't get mad I got aggravated because you want to be spoon feed an answer that it seems I'm not able to do.
I have told you but you seem to be obsessed with long drawn out absorb stage with decreasing current, which is understandable because that is the wet/ agm way.
What mobilesport posted in his charging is the same thing that happens in my pack, the difference being done by solar and there is always a load on the system.
Sure I know the capacity it's you not grasping the lfp characteristic to fully charge individual cells that make up a battery and interaction of the bms or my case cpu. A few things it does and being displayed in real time on the display connected to the CPU and can be viewed in the 5th wheel.
Battery Pack Voltage is the total battery pack voltage. This updates in real time and the numerical value is displayed below the bar. This bar will be green whenever voltage is between 3.0V x N (the number of cells in the pack). When the voltage drops below 3.0V x N the bar will turn red to indicate low voltage. The bar will also turn red when the voltage rises over 3.4V x N to indicate that the target charging voltage range has been attained. If the voltage goes outside of the range of the bar and off scale message will appear.
Battery Pack Current is the current either being drawn from the battery or being recharged in to it. Like the voltage bar this is indicated in real time and the numerical value is displayed below the bar. This bar will be green and will turn red when current is above 200A. When current is
negative and the battery is being charged this bar will turn white and “Charging” will be displayed.
Battery Pack Capacity is the battery state of charge. It works by tracking the amount of charge that goes in and out of the battery pack. It will reset to 100% during charging when the current is within a normal charging range for a battery charger and the total battery pack voltage reaches 3.52 x N (the number of cells). When the system is powered up for the first time this value will read 50%. The battery will have to be charged to full in order to reset the capacity reading correctly to 100% the first time.
As mentioned before what resets capacity...The EMS/ CPU system has a minimum recorded resolution of +/- 0.5A so any current below that level is not accounted for. The system could be setup for a finer resolution, but the shunt value would have to be reduced which reduces the systems maximum current capability.
The system will reset the capacity to 100% whenever the pack voltage reaches 3.49 to 3.52 V/cell on average and the pack current must be negative (charging) and typically under 35A and then it will set the capacity to 100%.
It's not rocket science it's just a different chemistry with different characteristics. After the parameters have been set it has really been a set and forget system with out the need to hen peck it or continuously try to out guess it.
