Pendleton ebike Demeter battery issue

[Erch007]

Hi everyone Im new to the site and would like some help if this is ok? I bought my wife a Vic Pendleton ebike a few years ago and its been sitting in the garage for a while after a house move and has not been on charge. I have searched youtube and online and have made some progress:
When the battery was plugged into the charger it only had the red and green light showing - not charging.
When I disconnected the battery from the charger I didnt have any lights showing any charge. I opened up the battery to check for any corrosion - none evident. I then noticed when I plugged in the charger lead that I got an arc and the battery charger was then showing 2 red lights. Mmm charging I thought??
When I pressed the battery test light I got all green lights except for the 20% light which was red. I disconnected the charger when the light went green / red and again no lights.
I have opened up the battery again and checked for voltage and I do have 40.2v on the BMS from the VP and VG connections. When I check for voltage again at the DSG and VP connection I dont get any voltage. Im assuming there is a problem with the BMS??
Can anyone help please?
Its a DEMETER 36V battery

 

[saneagle]

Hi everyone Im new to the site and would like some help if this is ok? I bought my wife a Vic Pendleton ebike a few years ago and its been sitting in the garage for a while after a house move and has not been on charge. I have searched youtube and online and have made some progress:
When the battery was plugged into the charger it only had the red and green light showing - not charging.
When I disconnected the battery from the charger I didnt have any lights showing any charge. I opened up the battery to check for any corrosion - none evident. I then noticed when I plugged in the charger lead that I got an arc and the battery charger was then showing 2 red lights. Mmm charging I thought??
When I pressed the battery test light I got all green lights except for the 20% light which was red. I disconnected the charger when the light went green / red and again no lights.
I have opened up the battery again and checked for voltage and I do have 40.2v on the BMS from the VP and VG connections. When I check for voltage again at the DSG and VP connection I dont get any voltage. Im assuming there is a problem with the BMS??
Can anyone help please?
Its a DEMETER 36V battery

If it's entered sleep mode, you need to leave it on charge for about 10 minutes to wake it up. Did you try that?

 

[Erch007]

Thanks for the reply, yeah Ive tried that. When I plug the charger in the status lights on the charger dont change to 2 reds.

 

[Ghost1951]

I had one of these with an identical problem some three years ago now. We bought it for about £350 as needing a new battery. The bike had barely ever been used and had spent a winter and more unattended in a garage.

I cured it by very very carefully charging it for about ten minutes on its output port.

There are people here who still hate me for advocating doing this. It would obviously be VERY dangerous to charge a battery like that for a long time and going away and leaving it unattended, but it worked for me and it has worked for other people too.

ONLY A FEW MINUTES and measuring the voltage on that port as you do it. You ought to see the voltage on the output port rise to something like 35v. Then try it by the proper charging method. You will need to rig up some wires to make the connection between the charger and the port. You sound like you know what you are about so will be able to do it. If not - don't.

It still even now will run for well over 25 miles.

 

[Erch007]

I had one of these with an identical problem some three years ago now. We bought it for about £350 as needing a new battery. The bike had barely ever been used and had spent a winter and more unattended in a garage.

I cured it by very very carefully charging it for about ten minutes on its output port.

There are people here who still hate me for advocating doing this. It would obviously be VERY dangerous to charge a battery like that for a long time and going away and leaving it unattended, but it worked for me and it has worked for other people too.

ONLY A FEW MINUTES and measuring the voltage on that port as you do it. You ought to see the voltage on the output port rise to something like 35v. Then try it by the proper charging method. You will need to rig up some wires to make the connection between the charger and the port. You sound like you know what you are about so will be able to do it. If not - don't.

It still even now will run for well over 25 miles.

View attachment 62780

Hi I saw your suggested fix on another thread. I wasnt overly confident of doing this as I dont undserstand what you meant by the output port. Is it like back charging and py-passing the BMS? Ive also just found out that the fuse holder had some dirt in it and was not showing voltage at the battery connectors it is now after cleaning it up

 

[Nealh]

Depress the battery button for 30 secs to see if it will wake up and charge.
Or
If one has the battery open disconnect the BMS multi wire/ribbon connector , then reoconnect it to see if the battery then wakes up.