Faulty Battery or Charger or both ?

[Sherlock349]

Hi All, new to forum, living on the beach in Belize.
I had a 36 v Chinese Ebike front wheel conversion for 4 years, completed about 2K miles on it without problems.
Battery started to lose charger, shorter distances so decided on new kit.
I got a 48v 1000watt kit from ebay, front wheel conversion.
Everything assembled correctly, completed 125 miles. Battery now wont charge and not holding charge (zero on multi meter). Charger not putting out charge according to multimeter (about 15v)
Battery was discharging progressively more quickly between charges.
If I connect 36v charger that puts out 42v the battery charges and shows holding and putting out 42v
Connect battery to bike controller will not come on.
If I connect charger to bike controller comes on an motor works.

At the limit of my diagnosis, could the BMU/controller be the problem.

Any advice thoughts help appreciated

 

[Sherlock349]

These are images of battery and charger labels

 

[www.recumbents.com]

Sounds like the charger died to me. It should be putting out about 50V.

 

[fechter]

42v would be correct for a 36v (10s) battery. If the charger can run the motor, it sounds good (at least the 36v one)

Many chargers have a safety feature that will prevent output until it "sees" battery voltage.
You could try measuring the voltage across the charge connector on the pack.

If the controller lights up when the 48v charger is connected but not when it is disconnected, it points to something in the pack, like a bad cell. You may need to take apart the battery to measure individual cell voltages to tell.

 

[docw009]

The 48V charger should be at 54.6 volts open circuit. If you only have 15, it's busted. WHen your bike runs off charger, you mean the 36V charger?

The 36V charger should be at 42.0 volts open circuit. Connected to your battery, it is correct that it stops at 42 volts.

Your new controller probably has its low voltage trigger right around 41-42 volts. I recall that my BBS02 mid drive kit, set for 48V battery will trigger a low voltage alarm if I connect a fully charged 36V battery. Tapping the throttle shuts it down. So I am not surprised that your relatively simple 1000W kit does what it does.

Try another 48V charger.