Recent content by Peter.bp

It seems to me that this one is 8S4P configuration. It is visible 8 BMS wires on top, missing BMS wire for most negative contact (B0 or B-). B1 BMS wire is black one and B8 (or B+) is red. Definitely not 48V.

Here's 20S BMS: The 6.2R/2W resistors are mounted on bottom of Al bar (50*5*250mm). The BMS has been tested with 16S/8A charger and 200W 24VDC halogen light bulb (inrush current >30A), no problems found even in communication. As this BMS is to deliver away, everything is additional isolated...

If it is LiIon/LiPo it's probably at the end of its' life, but this is not the case for LiFePO4 batteries. Only way is to measure individual cell voltages at end of charging (with charger still connected) and after it dies under load. - If all cells have similar voltage - the pack is at the end...

Nope, it is 0.02cm3. 10x10x0.2mm is 20mm3, in order to convert to cm3, you have to divide this figure by 1000.

Most important detail is missing: balancing current. I'd be surprised if your BMS has balancing current above 100mA, it is probably around 60mA or even less...

It's even worse: have you observed the connections? Between bus bar and crimped lug is inserted a nut, which is not brass, as well as the screw??? Maybe guy knows how to solder, but he definitely needs some education for wiring... :roll:

About connecting optocoupler to charger: do you have any electronics repair service in your neighbourhood? Most electronic techs can solve this problem quickly...

Take care about balancing current first. Check these 16 resistors close to balance connector, which value is written on them? Usually such BMSes have low balance current (~60mA) and thus it is not advisable to use couple cells for light... In addition, it is advisable to check standby current...

You did not connect yellow wires to plus pole of the battery... Plus pole for charger and for controller should be connected there (+ pole of the battery) too.

Do you really believe that it is possible to put almost 10Ah into 18650 case??? My advice: forget any Ultrafire cells.

If you brought that cell to only 3.0V before putting the battery on the charger, it is highly probable that that cell is still flat. It is important to check the voltage on that cell when your charger stops charging the battery. Before you replace faulty cell, try to charge it to 3.7-3.8V after...

It looks like most positive cell triggered LVC as it has only 3.4V and LVC has been set to too high voltage... The BMS still can be good enough... As I see, other cells are also almost flat as their voltage is between 3.5 and 3.6V... Try to charge the pack (it is almost empty) and check cell...

As the BMS will cut out on low voltage, it is obvious that the available energy will not be same at e.g. 0.05C discharge and at 1C discharge rate due voltage sag... In addition, the delivered energy is also reduced by losses on internal resistance of the battery. In other words, the Ah ratio of...

Maybe this picture helps: In the bottom diagram the battery current is shown in orange colour and the phase current is shown in orange and green colour. The phase current is 120A and the battery current is only 30A... Usually phase current is limited through peak current (in this case ~143A)...

B-, then sampling wires (push in the connector first negative side), then (if exists) B+ and after that the rest.