Solar Battery Bank (lithium cells)

thingiverse

Living in Wales can at times be like living on the dark side of the moon. Therefore, when the sun comes out I have to make the most of it with my solar set up. The problem with lead acid batteries is that they take a long time recharge. So, I set about experimenting with secondhand lithium laptop batteries. The pack shown here was designed to replace my water pump battery (12v 5Amp/hr mobility scooter battery). The circuitry allows the output voltage to be controlled, so that the pack can be used to charge a variety of other things apart from just running a 12v pump. The pack proved successful in trails, charging much faster. However, after a couple of recharges the last cell in the series died. It did this twice in a row. I know that there circuits available that ensure each cell is charged equally, however I do not think that is the issue here as all the cells were from the same laptop and stated off equal. I am going to try some band new cells, as the laptop I got the trail cells from was very old and I think the battery was shot to start with. I will update this accordingly.