rocky yeung
Member
Bike model : 2018 Specialized Turbo Levo FSR COMP 6 Fattie battery
Problem : battery cut out at 4th LED, 1st LED being the red lowest one.
Repair warning : At your own risk. Careless mistake may short circuit that may cause sparks, fire and then explosion if ignored.
How it happens :
Pre condition : I left the battery in fully charged status seperated from the bike for a few months due to fork repairing work that is waiting for spares.
What happens : Power on shows 9 LED. Top it up to 10. Test ride : battery cut out at 6th LED. I thought it might be bad contact but no luck.
What next : clean and exam contacts, or any wire damages, no luck. So recharge the battery for another test ride, it started up again. Happy for a ride until it cut out at 4th LED. Repeat the same examining steps, no luck. Only recharge the battery can start up the battery again. This is the first time I learn after battery cut out, you must recharge the battery to reactivate it again. (I confirm I charge it just for 3 mins it can restart again, I don't expect it will drain to the red LED. In fact it cuts out after a short distance ride.)
Headache now : Why it cut out while still shows green LED indicating it has power. I start to think there must be some battery problem inside. Experience tells me some batteries are in low voltage inside the battery module such that it refuses to be discharged. However not this case because I can charge it. I decide to contact the factory and bike shop that I brought it from trying to get some clue. I have no LBS to handle EBIKE. Battery is 1.5 years old still within two years warranty. Till I have fixed this problem and today I still receive no reply, not any initial reply, from these two sources !!!
What can I do : 1. keep using the battery in this unstable condition. 2. buy a new one. So without any original manufacturer's help I decide I will not ride with this battery in an unexpected cut out status, you know it is very unpleasant to ride up hill to get back home in a very hot day while it suddenly cuts out. So I pull apart with reference to this The Battery Doctor video.
What found : Total 40 batteries divided into 10 groups in series makes up 37V or peak 42V.
Measurement immediate : Total 35.5V. All groups 3.5V except one group 3.1V
Recondition : Use Li-ION battery charger to charge this group up from 3.1V to 3.5V is OK but it is quite difficult to justify the exact 3.5V as other groups. So I charge every group individually to maximum until the charger stops. This makes sense that every group stays at the same level.
Finally : I put back everything and charge it with factory charger.
Test ride : I climb up 900M hill with minimum foot work. Before the fix, it can only climb 650M. My intention is to burn out all the charge. Yes, it does go back to one RED LED now. Did another two power burns and same results. I am happy with this condition now so it is all done.
Battery health : before recondition is 95%, after fix is 90%. Don't care about this as I don't know how it calculate the health value. May be a combination of voltages and internal resistance whatever.
Conclusion : Due to battery management system BMS kicks in to protect the battery from dropping too low voltage, it cut off the supply at around 3.0-3.1V though other groups still may have 3.5V. That is why it still shows high voltage but will not supply any output in my case. I don't know if this situation is caused by these reasons : I seldom ride the battery to flat and then charge it back up; I left the battery too long, a couple of months. Well I suggest you occasionally flat the battery just to check it goes all the way down to RED level.
Some extra battery operation :
You can use the Mission Control apps to read the bike and battery information. Without the battery connect to bike motor, you can read battery only. Otherwise you can read both.
Power on battery, you can measure the battery terminals. It is exactly the output voltage. My battery reads about 0.2V in power off status.
If you are this battery expert, may I ask you some questions here.
1. Could you tell me how to read the little red LED on circuit board. Before the fix, this LED fast blinks around 9 times in 3 seconds and then 29 times slow blink in power on mode. Stop blinking after a long time idling. Very long time means may be hours later.
2. There is a small push button next to this red LED, how does it use. (Reset ? Diagnosis?)
I have been busy, I may not have time to read and answer your questions. Sorry for that.
Many thanks.
Hope this information may give someone help if it happens the same to you.
Cheers,
Problem : battery cut out at 4th LED, 1st LED being the red lowest one.
Repair warning : At your own risk. Careless mistake may short circuit that may cause sparks, fire and then explosion if ignored.
How it happens :
Pre condition : I left the battery in fully charged status seperated from the bike for a few months due to fork repairing work that is waiting for spares.
What happens : Power on shows 9 LED. Top it up to 10. Test ride : battery cut out at 6th LED. I thought it might be bad contact but no luck.
What next : clean and exam contacts, or any wire damages, no luck. So recharge the battery for another test ride, it started up again. Happy for a ride until it cut out at 4th LED. Repeat the same examining steps, no luck. Only recharge the battery can start up the battery again. This is the first time I learn after battery cut out, you must recharge the battery to reactivate it again. (I confirm I charge it just for 3 mins it can restart again, I don't expect it will drain to the red LED. In fact it cuts out after a short distance ride.)
Headache now : Why it cut out while still shows green LED indicating it has power. I start to think there must be some battery problem inside. Experience tells me some batteries are in low voltage inside the battery module such that it refuses to be discharged. However not this case because I can charge it. I decide to contact the factory and bike shop that I brought it from trying to get some clue. I have no LBS to handle EBIKE. Battery is 1.5 years old still within two years warranty. Till I have fixed this problem and today I still receive no reply, not any initial reply, from these two sources !!!
What can I do : 1. keep using the battery in this unstable condition. 2. buy a new one. So without any original manufacturer's help I decide I will not ride with this battery in an unexpected cut out status, you know it is very unpleasant to ride up hill to get back home in a very hot day while it suddenly cuts out. So I pull apart with reference to this The Battery Doctor video.
What found : Total 40 batteries divided into 10 groups in series makes up 37V or peak 42V.
Measurement immediate : Total 35.5V. All groups 3.5V except one group 3.1V
Recondition : Use Li-ION battery charger to charge this group up from 3.1V to 3.5V is OK but it is quite difficult to justify the exact 3.5V as other groups. So I charge every group individually to maximum until the charger stops. This makes sense that every group stays at the same level.
Finally : I put back everything and charge it with factory charger.
Test ride : I climb up 900M hill with minimum foot work. Before the fix, it can only climb 650M. My intention is to burn out all the charge. Yes, it does go back to one RED LED now. Did another two power burns and same results. I am happy with this condition now so it is all done.
Battery health : before recondition is 95%, after fix is 90%. Don't care about this as I don't know how it calculate the health value. May be a combination of voltages and internal resistance whatever.
Conclusion : Due to battery management system BMS kicks in to protect the battery from dropping too low voltage, it cut off the supply at around 3.0-3.1V though other groups still may have 3.5V. That is why it still shows high voltage but will not supply any output in my case. I don't know if this situation is caused by these reasons : I seldom ride the battery to flat and then charge it back up; I left the battery too long, a couple of months. Well I suggest you occasionally flat the battery just to check it goes all the way down to RED level.
Some extra battery operation :
You can use the Mission Control apps to read the bike and battery information. Without the battery connect to bike motor, you can read battery only. Otherwise you can read both.
Power on battery, you can measure the battery terminals. It is exactly the output voltage. My battery reads about 0.2V in power off status.
If you are this battery expert, may I ask you some questions here.
1. Could you tell me how to read the little red LED on circuit board. Before the fix, this LED fast blinks around 9 times in 3 seconds and then 29 times slow blink in power on mode. Stop blinking after a long time idling. Very long time means may be hours later.
2. There is a small push button next to this red LED, how does it use. (Reset ? Diagnosis?)
I have been busy, I may not have time to read and answer your questions. Sorry for that.
Many thanks.
Hope this information may give someone help if it happens the same to you.
Cheers,
Last edited: