LiFePo4 batteries - DIY BMS.

 

What could possibly go wrong...

The disclaimer: There is no expectation that this will (or will not) work and be safe in the real world, if it does then great, doubt it though - imho an emotional attachment to success can be dangerous, if it doesn't behave rock solid then an off the shelf BMS will be purchased. The journey is the destination. If anyone blows themselves up following anything in this post - not my fault! 😊

Overview:

Already on the web there's an awful lot of information about LiFePo4, no point going too deep here but a few points are very important for charging & general use.

• Don't let any cell go above 3.65V
• Don't let any cell go below 2.5V
• The cell voltages should all be very similar

The cells were bought from DocanTech and Jenny Wu was just great every step of the way, very reassuring. Total cost delivered to Portugal was  $591.68. Shipped 25th Feb, received 10th May. No local tax. 

Cell datasheet below. 

Measuring the cell voltage