Can you explain exactly what youre doing with the test? You set quite a high voltage on the psu but as its max current out is 40A it only drives at 7v, then if the module is bad it can't absorb power for long (high internal resistance?) And the psu starts increasing the voltage to maintain 40A? Im currently capacity testing modules with a 5A tester. Its very slow and also im not seeing the bad modules im expecting to see! Great work. Thanks for any advice!
In each brick there are 2 cells that max out at 4.2V each and therefore 4.2V x 2 is 8.4V at the top. Most of these cells were about 10-20% charged at around 3.5V-3.6V. If the capacity of a cell is good, it will take the 40A charge and slowly increase the voltage. Inversely, if the capacity is poor, you will see a spike in the voltage. Think of it this way. Using a fire hose, you fill up a pool which represents a good cell. You turn it on and it can take pretty much whatever you throw at it. The bad cell is represented by a bucket. Very shortly after turning on the fire hose the bucket is full because it has very little capacity. In a battery pack like mine, the constraint of overall capacity is determined by the cells with the least capacity. The BMS software monitors the top and bottom voltages to turn the inverter off at those levels. If my overall battery is at 10% and the inverter starts charging it up with solar production, once the bad cell reaches 4.15V (my BMS limit) the BMS will tell the inverter to stop charging, leaving me with a battery that might only be 15% full overall. While these cells do have some degradation, you want them all to have a similar capacity because you are limited by the weakest one.
Hi, please help with information , I have the gen 2 batteries but on 6 X bricks , I am getting at best 49.2 volts . 8.1v per brick . For safety. I have had to go to 7 X bricks to total 56.7v please help me get over 9 volts per brick , so I can reduce weight and space. Thank you this is very exciting news 🙏. Regards Colin.
You can not increase or decrease the limits of the cells. 4.2V is the very top of the cells, I would suggest staying under this at a top of 4.15V or 8.3V for you setup. If you have only 6 cells, you won't have the right voltage for 48V applications. My minimum pack voltage is 42V, and max is 58V.
No, actually what I said was 6 bricks in Parallel and 7 sets in series. Putting cells in series (a chain of positive to negative) increases the voltage, therefore (7 x 2) x 4.15V is about 58V.
@@jdsolarandev2591 I just went back and checked, 7 setts X 6 bricks in series =42 6 bricks in series = 50 volts . Not 57volts 'ish Plus you removed my comment s. So Rather than correct your mistakes and save a posible over charge fire 🔥 . some poor person will lose there house. To A battery bank bursting into flames . They may have children and there parents at there home ? The truth will Save an amateur losing everyone and every thing dear to them. Because you will not edit your video. Wow. Wow 🤪
When watching a friend disassemble a LEAF pack to salvage the cells, he was wearing electrical insulating gloves. You seemed a little cavalier when handling the bus bar while aligning the stack. Is there no danger of shorting terminals to cases? Maybe not in that alignment step, since only one set of terminals is involved, but as you are adding the other bus bars, isn't there a point where it becomes dangerous?
