Battery Health Question

[dustinwiththeredbike]

Hi! I just purchased a used eBike, an American Flyer that's a few years old. It's a 48v system with a 750kW direct-drive hub motor. The bike runs at about 23mph at full charge, but speed drops to 20mph at three out of four bars on the battery meter and then down to about 15mph after that. It has a 48v 11.6ah rack-mount battery. I tested voltage at full charge: 54.6v. Haven't tested at lower charge levels yet and I'm not sure when it hits 48v or lower.

Question: Is this normal? Could the battery be worn and need to be replaced? From what I've read, the battery should drop to 48v at about 50% charge. If it drops to 48v before that, does that indicate a worn battery?

Thanks!

 

[HumanPerson]

Might have been rode hard and put away tired in its early life?
The battery could have some weak/dead cells or the BMS could be goin bad.

There are alot of determining factors...how hard was it rode....was the battery balanced or just not taken care of....
What year, make and model is it?

There is a low voltage cutoff and other settings that should be looked into...

Hopefully others that might know about your bike will chime in

Welcome to our Humble Home by the way

 

[procreator]

Check out this chart:

https://ebikesforum.com/resources/48-volt-13s-battery-voltage-chart-li-ion-batteries.37/

 

[dustinwiththeredbike]

Might have been rode hard and put away tired in its early life?
The battery could have some weak/dead cells or the BMS could be goin bad.

There are alot of determining factors...how hard was it rode....was the battery balanced or just not taken care of....
What year, make and model is it?

There is a low voltage cutoff and other settings that should be looked into...

Hopefully others that might know about your bike will chime in

Welcome to our Humble Home by the way

Thanks! Yeah, the bike's history is kind of a mystery. Got a good deal on it because some of the traditional bike components needed help—derailleur was wonky. It has about 400 miles on it. It's probably a bit worn out .

 

[dustinwiththeredbike]

Check out this chart:

https://ebikesforum.com/resources/48-volt-13s-battery-voltage-chart-li-ion-batteries.37/

Thanks! This is perfect! I'll continue to test for science, but I'll probably pick up a new battery for it.