edventure said:
ihategeeks said:
Yes i have a multimeter, that is how I am taking readings , the battery won't even power the Cycle Analyst, I'll need to look up how to measure each cell.
The ping batteries have BMS's mounted inside of their heat-shrinked shell. The only way to tell the individual cell voltages would be to carefully open the heat-shrink sleeve and try to access the wires leading to the BMS since this would probably be the easiest place to monitor on these types of packs. The click seems really strange. One possibility is a cap or FET popped on the BMS board, but they usually don't click. Its more like a little pop and or fizzle. If this was a pack someone modified, they may have placed some type of circuit breaker in line with the pack, which if this was the case it should be easy to correct, but you will need to find it first. A couple questions:
The sound could have be characterized as a pop, it just sounded more like a click to me. Also, when I removed the battery from the case I noticed the BMS has a mild scent to it.
The scent was probably something on the BMS burning out. It could have also been a shorting wire causing the insulation to burn, but my first guess would be a component on the BMS.
Where did you purchase the pack?
From Ping directly in April 2013 48v15ah V2.5.
Probably not modified, this is why I had asked this question.
There are no modifications that am aware of.
Have you separated the 24V and 48V packs since this has happened and tested with them isolated from each other?
That is when this happened. I already had the packs separated. I was testing them both individually so I could see if the diodes were pulling volts when in the circuit.
I was getting the individual voltages to record any difference.
Not sure of the order here, but if the sound and smell came while the batteries were still together or even while separating them, if there was a problem with the 48V pack, "low cell" it could have been drawing an excessive amount of current through one or both of the diodes, so it is possible the smell came from the diodes. This does would not mean the diodes caused the problem, but a problem on the 48V pack may have caused them to fail. I have two 48V 15Ah packs on my bike, but decided not to place any diodes between them based on the fact that the diodes will actually cause a small voltage drop across them that will result in almost a volt lower at the motor/controller, "0.7V" Additionally this is just another component that can fail. Many people recommend them as if one pack has an issue it won't bring the other pack down with it, but I am taking my chances. Also, when I connected the pack I made sure both packs were charged to very similar voltages. In my case my two packs were only of by 15mV. The greater the difference in voltage when you connect them the greater the current flow between them. If there is a couple volt difference, you will get a spark when they are connected and if there is greater than a couple volt difference it could blow the diodes. The diodes should be of a high current value, to avoid this happening maybe someone else could recommend what they use, but if the packs were similar when connected this should not matter. As Dogman had said have you tried unplugging the BMS and measuring the voltage again? Also, are you measuring the voltage after the diodes? If you are try the voltage before the diodes too, maybe a stupid question, but I have to ask. If you have a drawing even a hand drawing of how they are connected that could help or a photo. You can also test the diodes with an ohm meter, with the negative lead on the striped side, "cathode" of the diode and the positive lead of the meter on the non striped lead you should get some high possibly 1M ohm resistance, but if you reverse the leads the resistance should be infinite. If they are measuring very low resistance in both directions they are probably bad. I would recommend to remove the diodes from the circuit before testing since there is always a danger of shorting something when in the circuit.
Did anything get warm when this happened?
No.
That's one good sign.
I have a few other things I would like to say but my wife is going to kill me if I keep going, i have three kids and we are heading out the door. i will check back in later to see if I can still offer anything. Again, good luck I know this can be frustrating. Just keep a level head and you will get it figured out.
Is it a $10 Multi-meter you are using to check the voltage? "I have seen very inexpensive multimeters fail and have very low impedance at the terminals"
Also need to be careful not to measure in resistance or current modes, because this could also cause a large current draw.
Meter is a southwire 10030S purchased from lowes for 20+ something.
Meter probably not an issue, but I just figured I would ask.
Meter was set to 600 V DC.
Meter was reading the 24 volt battery with no problems and got the same as the Cycle Analyst.
