Battery not charging / no spark

[vinylfix]

I took my daughter to the playground today when a toddler knocked over my converted Tour Easy (thank you very much). Upon inspection the only damage I noticed was the bent faring and side mirror, not a huge deal, I was more bothered by the nonchalant attitude of his mother. However, later as I tried to charge the battery (48V 30AH twin Ping battery pack) the controller wouldn't turn on. I check for any torn or damaged wires but everything looks normal. I didn't think the fall was hard enough to damage the battery plus it didn't take a direct hit (it's also in a metal case). I've noticed there's no more spark when connecting the Anderson connectors to the charger cables. How would I go about trouble shooting this?

Any help is greatly appreciated!

 

[dogman dan]

First thing to look at, do you see any voltage at the charge plug on the battery.

If yes, then do you see any voltage on the charge plug of the charger?

In other words, make sure the plug does not have a broken wire, where the plug solders to the wire, before digging any deeper.

It could easily be totally random, and nothing at all to do with the bike falling over. In fact, if there is no visible damage, I bet it's not that tip over that caused it.

Once I had a ping battery fly over my head, landing in the dirt 30 feet ahead of my bike. It was fine, but was protected some by a plastic box, and must have not landed on a corner too hard. It should take a lot more than a tip over, to make the bms stop working, and not allow a charge. But your bms could have failed, with the charging fet dying, just from many charges. If it's not the plug, then look next at the bms. See if one of the fets looks all toasty. Look for the obvious, like any wires with poor looking solder where they connect to the bms.

Take good pictures if you actually unwrap the bms. They will help the really smart guys, like Dnmun. I just know simple stuff, like hey, that hole melted in the bms shrink might mean something.

 

[dnmun]

you seem to have the battery split in two pieces so the sense wires run from one side to the other and i suspect that one of them or more could be either damaged or maybe the wire pulled the sense wire plug out of the socket.

you can check if the BMS is functional by measuring the voltage on the gate of the output mosfets. i doubt if your charging mosfet is turned off since you don't have high voltage on any channel because you had not been overcharging it already. so check the source/gate voltage on the output mosfet.

if you can find a S/G voltage there then the BMS should be ok and you should look for an open connector somewhere else.

legs on the mosfet are gate drain source. measure with the 20V DC scale.

 

[vinylfix]

The voltage at the connectors read:

Anderson connectors from Battery pack: 113 volts
Anderson connectors from Charger : 123 volts

This is a split pack with sense wires. I disconnected all the wires according the Ping's wiring guide and reconnected them making sure they're tight - still nothing happens when connecting to the charger. This is a newer battery, about 2 months old with 45 cycles on it. The battery seems to work fine, I was riding all day yesterday with no issues at all, only when I tried to charge it did I notice a problem.
I'm assuming I'd have to take the BMS apart in order to measure the Source/Gate Voltage.

many thanks for the tips,

Marc

 

[vinylfix]

I just realized I had the meter set to AC, the correct readings are:

from battery 51.3
from charger 53.9

 

[999zip999]

Sometimes just one sense wire gets pulled out the housing.

 

[vinylfix]

You were right Dogman Dan, it was totally random! Turns out the charger is bad, the charging voltage should be between 59.5-60.0V. I suppose I was just too convinced it had something to do with the fall - we live and learn 8)