48V only showing 14.4V

[backwoods_hiker]

This morning I went to take off on my bike my with a fully charged 48V15AH Ping. I got just a little bit of power and then nothing. Checking my battery it was only showing 14.4V so I put it back on the charger hoping it needed to balance or something. I take it off and it says around 58V okay I try again and same thing happens little power then nothing. I test the battery I get 14.4V back on the charger for only 1 minute take it off and test it around 59V try the bike again same results if I leave it on for an hour or a minute I get the same results. It's a 5A charger and a high rate BMS

 

[Rassy]

I had a similar issue with a 3 year old 48V 15AH Ping. I replaced the BMS and all is good now. See this thread:
https://endless-sphere.com/forums/viewtopic.php?f=14&t=80244&p=1187555&hilit=Ping#p1187555

 

[backwoods_hiker]

I took all the tape off and put the battery on the charger and all the BMS lights are lighting up.

 

[Rassy]

I expect that exactly what has gone wrong with your battery/BMS and what was wrong with mine may be different, but this quote from 999zip999 convinced me to go ahead and replace my BMS:

Buy new Ping BMS. This can save a battery.

As can be dug out of my thread, my battery/BMS was working perfectly except right at the full charge point which I could control by "manual manipulation" of the BMS.

If you wish to determine that it is a BMS problem before purchasing a new one I recommend the following procedure:

Cut the large black negative wire between the BMS and battery. Also cut the large black negative wire between the BMS and the controller. (you will need to do this to install a new BMS anyway). Install bullet connectors (or whatever) where you cut the black wires, such that you can plug the wires back together. Make a jumper wire that allows you to bypass the BMS by plugging one end of the jumper into the wire coming from the battery and the other end into the wire going to the controller. Now you can use the battery in bypass mode to see if it works properly, but also plug the original wires back together for charging purposes.

If the battery works properly when you bypass the BMS you have effectively proved that the BMS needs to be repaired or replaced.

Edit: You may not need to make a separate jumper wire if there is enough extra wire such that you can connect the wire from the battery directly to the wire going to the controller. You need to install your bullet connectors (or whatever) so that the male and female ends mate properly.

 

[backwoods_hiker]

I unplugged the BMS and plugged it back in and everything is working fine again. Rode around the block in the dark with no lights. I hope it cured my problem. Thanks ES and Rassy Good Luck with yours.

 

[999zip999]

Always do ez free things first. On a Ping pack its easiest to buy Ping singalab bms. Ping has always been a good man. His batteries have a power rating if followed they will last many years.
Let us know how it works out.

 

[dogman dan]

FWIW,, for other readers, what was going on was the plug for the small bms wires was loose, or somehow had a bad connection.

I thought he was going to find a bms wire broken at the solder to the tab of a battery.