Category Archives: lithium battery

if your lithium battery with BMS or not

Posted by on March 13, 2025 No comments

Does your electric bike battery has BMS function, if with BMS function,had better to always make this red button to be “down”(Don’t be up)… (After testing, LCD-008HU is no problem for working with the battery without BMS function.)

This red button be “up”, when ride, press brake lever,it will reverse charging battery.

It is necessary to confirm whether the lithium battery has BMS function. If the electric bike battery has BMS function, if the battery is full, use the reverse charging function of the controller, and the battery protection will not absorb. Then the reverse current of 70V, 80V and 110V will be reverse charged to LCD and controller.

The controller has a large capacitance, which can absorb the counter current. But LCD does not have a large capacitance, it will act on the LCD switching power supply and burn the switching power supply.

Other LCD-003 use resistance step-down power supply, reverse charging, resistance can step-down, will not damage the switch.
But for the LCD with USB port, the USB module will be burnt if the counter charging exceeds 70V
Because there are a lot of things that need to be lit for this color screen instrument. It uses the switching power supply. If the reverse charging exceeds 70V, the switching power supply will be burnt out

If your lithium battery has BMS, can’t make that red button to be “up”(three button switch). (red button should as “down” as below picture)
Had better Not use this red button. Thanks.

Error 4 stop hub motor working

Posted by on March 10, 2025 No comments

Q: I bought a hub motor few months ago. Display error 4 is your brushless controller LCD? And I have a problem in the moment, because I install it and when I start to move the quad appears all the display the error 04 and a symbol of a tool, I had seen at the forum what’s the error meaning, but I think it’s something different because it had full charged electric bike battery pack.

A: How long did you use this electric bike battery pack ?

Q: It’s new. I have used ones for test the hub motor. It start full at the display but 100 meter later appear the error, hold on, then when appears the error, 10 minutes later in the display appear again full the electric bike battery that I use is a 4 lead batteries of 12V 45 Ah

A: Is your electric bike battery is 48V? That’s correct. The issue is battery. Do you have volt meter?

Q: Yes. I can find one.

A: Ride this bike and use volt meter to test the voltage of electric bike battery. If the voltage will drop down. The problem comes from electric bike battery. If the voltage drop down to 42V, the error will appears. If you don’t ride, the will display appear full.

Q: I’m trying to start the hub motor without any load. It works for 6 hour more or less.

A: How many current does your electric bike battery can offer? 10A , 20A or larger. You should use volt meter to measure the voltage when you load this hub motor.

Q: I bought 4 batteries of 12 V 45 Ah

A: Sometimes new electric bike battery is in stock for a long time. Even if No use. Also can need this issue. If you don’t load our hub motor, is there no error display?

Q: No, if it start to work freely, it work for 6 hours. How I use the volt meter to measure the electric bike battery? Working the hub motor ?

A: Connect red, black wires of volt meter to the positive and negative when the engine works,
watch the voltage on volt meter.

Q: Let me prove it, so I have to connect the positive of the battery to the positive of the engine and as well to the positive of the volt meter, and the same thing whit the negative ones, then star to work the quad watching the volt meter and if the voltage goes down the issue is in the battery.

A: Connect wires as before. Just add two wires from voltage meter. Red wire of voltage meter is connected to the positive of battery. The black wire is connected to the negative of battery. Make sure it on the VDC voltage position (=200VDC or ..)

Q: How volts it has to show to work properly? More than 48V ?

A: 42-60V

Q: Ok, so if the battery is full it has to show around 60V?

A: No, that depends on what type of battery. If LiMn2o4 is about 54V, LiFepo4 is about 58V. Lead acid is about 54V. When you test, the voltage will drop down. This electric bike battery is not good.

Q: I let you know if something different happen.

issue about electric bike kit battery

Posted by on March 10, 2025 No comments

We purchased an electric bike kit including motor controller, hub motor wheel, throttle, brake lever and with 36V 10AH bottle style Lithium Ion electric bike battery that used for testing 36V solar charger from one supplier, not from leaf motor. After charging this electric bike battery for 10 hours by better solar power, full charged, we rode the bike, but hub motor wheel only run about 8km.

We use a ampere meter in series to electric bike kit system, powered on and rode it. We got the current is about 5A. The speed is 257RPM.We use 26” hub motor wheel.

We calculate the speed is about 32Km/per hour.
See below formula:
（3.14×26”×0.0254）× 257RPM × 60 minutes ÷ 1000 (m-Km)=32km

If this is 10Ah battery, per hour lost 8ah.We can use 1.25 hours.
See below formula:
10Ah ÷ 8ah/per hour= 1.25hours

We think full charge this electric bike battery per time, the hub motor wheel can run about max 40 km. 32km/per hour × 1.25 hours = 40 km

There is definitely a problem with this electric bike battery, I’m not sure whether electric bike kit is because of the solar charging or our testing, or if it has a fault. But I need a replacement electric bike battery asap, because we don’t have any more 36v electric bike battery, and we sold 1 set of electric bike kit with lithium battery last week. I think BMS inside this electric bike battery no problem. The problem comes from the li battery cells. Maybe this electric bike battery had stayed in warehouse for a long time and haven’t charged it. It will make the electric bike battery cut down the achieve distances and use life.

So if solve this problem and let my hub motor to work asap, only replace all cells or replace new electric bike battery.

The issue about electric bike battery for bike kit

Posted by on March 8, 2025 No comments

We purchased an electric bike kit including motor controller, hub motor wheel, throttle, brake lever and with 36V 12AH Lithium Ion electric bike battery that used for testing 36V solar charger from one supplier, not from leaf motor. After charging this electric bike battery for 10 hours by better solar power, full charged, we rode the bike, but hub motor wheel only run about 8km. Then we use 110-230Ac charger to charge this electric bike battery and full charged it. After test, we found this hub motor wheel is still lasted for around 8km.

We use a amp meter in series to electric bike kit system, powered on and rode it. We got the current is about 5A. The RPM is 257RM. We use 26 inch hub motor wheel.

We calculate the speed is about 32Km/per hour.
See below formula:
（3.14×26”×0.0254）× 257RPM × 60 minutes ÷ 1000 (m-Km)=32km

If this is 12Ah battery, per hour lost 8ah.We can use 1.5 hours.
See below formula:
12Ah ÷ 8ah/per hour= 1.5hours

We think full charge this electric bike battery per time, the hub motor wheel can run about max 48 km. 32km/per hour × 1.5 hours = 48 km

There is definitely a problem with this electric bike battery, I’m not sure whether electric bike kit is because of the solar charging or our testing, or if it has a fault. But I need a replacement electric bike battery asap, because we don’t have any more 36v electric bike battery, and we sold 1 set of electric bike kit with lithium battery last week. I think BMS inside this electric bike battery no problem. The problem comes from the lithium battery cells. Maybe this electric bike battery had stayed in warehouse for a long time and haven’t charged it. It will make the electric bike battery cut down the achieve distances and use life.

So if solve this problem and let my hub motor to work asap, only replace all cells or replace new electric bike battery.

We are angry with our supplier, sent them many emails and no any reply.
Thank you, leaf motor. Help us found the electric bike battery ‘s problem. We are going to order leaf’s products in near future.

Hub motor, electric bike battery, electric bike kit supplier: Leaf Motor Technology Co.,Ltd

DIY kit with electric bike battery

Posted by on March 8, 2025 No comments

Q:I bought DIY electric bike kit unit and a lithium electric bike battery and installed on my bike a couple of weeks ago since I had gotten one of the a couple of days ago and I wanted to use my bike as soon as possible. I have driven the bike for a while without an issue. However, after 2~3 charges, the battery does not get charged anymore. When I plug the charger to the battery, I noticed that the charger LED still remains green. When it charged, it turned to red before. Would you please guide me how to resolve this issue?

A:The LED on your charger turn green quickly or can’t change color,it just means your electric bike battery doesn’t need to be charged.
Could you use a volt-meter to measure the voltage of your battery?How is the voltage?
Q:I measured electric bike battery:DC Voltage 30V.
This is what happened:
I fully charged the electric bike battery over night and went to work on bike next day.
On my return to home, when pushing down thumb throttle all the way down,hub motor was running for one second and down for two seconds and repeat. So I thought the electric bike battery was low.
A:If the voltage of your electric bike battery is 30V that means your BMS inside your battery have been protected.
You should take off all load,for example:headlights,led throttle,horn etc.Then the battery will return normal.
Could you disconnect all wires from your battery,then measure the voltage of battery again?
Q:Actually I measured 30V directly from the electric bike battery outlet. So there was no load when I measured it.
Is there anything I should check?I checked the output of the charger and confirmed that electric bike battery has output of 40V.
So upon plug it into battery, if I still have green LED, then there is a open circuit in the battery?
Is there anyway I can check this electric bike battery at the charging inlet or power outlet without opening the battery package?

battery level

Posted by on March 8, 2025 No comments

Q:small detail. lights of the twist is on but i run motor until battery come dead then the lights all together come off there is no color change when battery get lower

Answer 1:
yeah,seems it can’t display correct.
My 26″ rear wheel 48V 1000W electric bike kit,48V twist throttle with gauge
Power on 48V li battery,three leds(green,yellow,red) be on.
I ride for a long distance last time.Three leds still be on together.I thought it still could run more.After ten minutes later,green led was off.Only yellow and red leds be on and climb a steep hill,the bldc motor stopped.Turn off,then turn on,still can run.But it would stop at once.

Answer 2:
My 26″ 36V 250W bike kit with LCD display.
Though my throttle also has this battery level,I never notice it.
That LCD is really good,can display the voltage of battery,speed,mileage etc correctly.

Answer 3:
This battery level on throttle was designed as the voltage of lead acid.
1.More than 48V,green,yellow,red three leds all ON.
2.From 47V~48V,green OFF,yellow and red ON.
3.Below 47V,only red ON.

48V Battery Full charged G/OFF discharging R/ON discharged
Lead-acid 54V>48V(G,R,Y ON) 47V~48V(G/OFF) <47V(Only red on) LiMn2O4 54V>48V(G,R,Y ON) 47V~48V(G/OFF) <47V(Only red on) LiFePO4 60V>48V(G,R,Y ON) 47V~48V(G/OFF) <47V(Only red ON) When the voltage drops at 47V. 1.Lead acid still can work normal. 2.LiMn2O4 and LiFeO4 are hard to work,it can't supply large current,BMS will stop cells working.For example:the voltage of li battery is 48V,still climb the steep hill,green led will be off at once,after about 10s,yellow led will be off,only red led ON. Answer 4:
Never see this battery level.I will charge battery after running 30miles when it’s new.
Now I should charger it earlier.

Answer 5:
My bike kit works with 48V lead-acid battery,no problem.I will charge it when the green led is off.

Answer 6:
It’s a pity,this lcd can’t work with 36V 750W brushless controller.

Answer 7:
I found good led light,it can display battery gauge.

Answer 8:
My 250w electric bike kit working with lcd.

Answer 9:
Nice lcd and lights,but can’t find these lights shown on leafmotor’s website.

Answer 10:
I found a li battery on leafmotor’s website.It has gauge on battery shell.

Answer 11:
These green,yellow,red three leds on throttle only display approximately,if need to know exact battery gauge,I think had better to order LCD.

going to order leaf bike conversion kit with lithium battery

Posted by on March 2, 2024 Comments Off on going to order leaf bike conversion kit with lithium battery

Q:Going to order your 20 inch 72v 2500w bike conversion kit and will need a 72v lithium battery. Any recommendations? Like to have one built to these specs: 72v 40a BMS 1000AH

Here’s my Cargo Ebike: Eunorau G30 Orange Cargo Bike to check out the shape of the battery casing.

A: Yes,we can make 72V 18ah lithium battery.
Would you need 1000Ah?

Q: Also, on the 20″ 72v 2500w bike conversion kit, does it have Juliet connectors on all major components? Yes. I want a 1000ah pack.

A: 1000ah? It’s equal to 50 sets of 72v 20ah lithium battery. Your bike can’t carry these lithium batteries.
Your bike max use 72v 50ah.

Q: Ok. I’ll take the 72v 50ah lithium battery and it will lock in same position on the bike correct? 
And have a 40A BMS correct?(the controller in that kit is 40A max)
50ah I can ride for awhile between charges.
How many N.M. of torque does that motor produce?
On the 72v 2500w 20 inch bike conversion kit I also need a 7-speed freewheel. Will you install that as well? Eunorau G30 Orange Cargo Ebike

A: Yes.Can make 72v 50ah.But 3A charger charge battery is too slow.Also,too many cells.
We recommended 2 or 3 sets of 72v 18ah 40A lithium battery.That’s better than 1 set of 72v 50ah 40A

Q: What about 2 sets of 72v 30ah lithium battery?
I know even better 1) 72v 40ah 40a less cells and you can make it to fit in the housing of the frame .

A: Supply you frame size, let me check max can how ah.
We can customize lithium battery size as your frame.

60V 30AH electric bike triangle battery Custom

Posted by on August 26, 2023 Comments Off on 60V 30AH electric bike triangle battery Custom

Q: I’m interested in this 60v 30ah lithium battery but I have 2 questions. My controller has a max BMS of 45 and I see that this battery is rated for 30. Would that be an issue? If yes, can you guys increase it? The second question is that I like the size of this electric bike battery because it fits my frame. I was wondering if you can increased to amp hours from 30 to 35-40, without changing the battery size? I’d like to increase my range as much as possible. I don’t know if this is possible but I thought I’d ask.

A: 1. Your controller Max 45. — It’s fit for.  We can make battery’s BMS to max 40A or 50A
2. Yes, we can increased the Amp hours from 30ah to 35-40. If without changing the battery size. (Also, can supply your frame size to us. We can customize as battery as your frame.)

Q: I’m not quite sure which measurement is for the frame size, so I’ll just send 2 different ones, followed by a picture so you can see where I got them from. From the middle of the crank to the top of the seat it’s 17 inches, and from the middle of the crank to the horizontal top bar, it is 14.25 inches. However, I made a cardboard cut-out based on the dimensions provided on your website found out it’ll fit well. What’s the maximum amp hours that you can fit in a battery that size? 

A: We can make 60v 30ah fit for this frame.  (maybe 60v 35ah, 40ah)
If we can get actual size of this frame,then we can ask our factory to estimate max amp fit for this. 

Q: Going in a clockwise direction, the measurements are listed below:
444.5mm (across the top) X 571.5mm (bottom bar) X 279.4mm (vertical seat tube).

electric bike battery can’t be charged

Posted by on January 29, 2022 Comments Off on electric bike battery can’t be charged

Question:Ordered 1 set of electric bike battery one year ago,last night charged it for the whole night,rode it this morning,but the hub motor stopped less than 1 mile.

I found the green led on my charger always be on while charging,it can’t turn to red.

Answer:There are two leds on charger.One is green led,the other is red.
When red led be on that means it’s charging.It’s okay.
When green led be on,there are three status:
1.Full charged;
2.Charger doesn’t connected to battery;
3.Can’t charge li battery

Everyone know the first and second status.But the third status isn’t easy to identify.Above question belong to the third status.

Now we talk about LiMn2O4 battery.
1.24V limn2o4 battery:
Fulled charged:29.4V;Dis-charged:22V
Should charge battery before it drops 22V.
If voltage is less than 22V,the charger can’t charge battery because of over discharged.
2.36V limn2o4 battery:
Fulled charged,42V; Dis-charged:34V
Should charge battery before it drops 34V.
If voltage is less than 34V,the charger can’t charge battery because of over discharged.
3.48V limn2o4 battery:
Fulled charged,54.6V; Dis-charged:46V
Should charge battery before it drops 46V.
If voltage is less than 46V,the charger can’t charge battery because of over discharged.

Why li battery will be over discharged?
1.24V motor controller can work at 21V±1V;the under voltage of 36V controller is 31.5V±1V and the under voltage of 48V controller is 42V.
2.Li battery has BMS.If the voltage of 24V,36V,48V li batteries less than 22V,34V,46V.BMS will stop charging and protect cells.

We suggest charge your electric bike battery per 20 miles.
Now our motor controller works with LCD,this lcd can display battery voltage directly so that you know when you should charge battery.

electric bike battery can’t charge

Posted by on January 26, 2022 Comments Off on electric bike battery can’t charge

Electric bike battery can’t charge,how to handle it?


Question 1:Ordered 1 set of 36V/12Ah electric bike battery with charger from one supplier last March.Now the li battery can’t charge.I sent several emails to this supplier,no any respond.Angry and aspire to slove it,can you help me…

Last Monday,I charged it all the whole night,but the second day,when I rode for less than 1 mile,the motor stopped.Recharged it,found the green led always on,can’t turn red.

I DON’T KNOW how to deal with it.Need help…Thanks.

Answer 1:First you need volt-meter to measure the voltage of charger and electric bike battery.Then can find problem.

Answer 2:Full charged this 36V electric bike battery reaches 42V.
1.Use voltmeter to measure the charger can get 42V.If not,charger is broken;
2.Measure battery,output voltage:33~42V,battery is also okay.If less than 33V,can’t charge it.

Answer 3:Generally the charger can’t get trouble.The problem is always from cells.
If the electric bike battery voltage is over-low.Battery’s BMS will not allow charger to work. Can’t charge for ever.
You should remove the BMS inside ev battery and let it to charge cells directly.
When voltage of the whole cells is more than standard voltage and re-connect BMS to cells.

Answer 4:Ride e-bike about one year,never meet this problem.

Question 2:The charger output 42V,but battery is 31.5V.
Disconnected cover,found a printed circuit board.But don’t know how to handle it.

Answer 5:B- → battery – (connect the cathode of the last pack of cells)
D- → – (connect to lock)
C- → – (connect to cathode of charging point)

B1 B2….B10 connects each pack of cells.

Answer 6:Your charger can’t work normal.You should disconnect 10-pin connector.
Charge it from B- and the positive of electric bike battery,bypass BMS,directly charge cells.

Note:Generally BMS can protect cells over-discharge and over-charger.But if your motor doesn’t work,just led lights work(current is less than 1A),at this time,BMS can’t protect cells.It will over-discharged your battery and make the voltage is less than normal so that can’t charger it.

We suggest if don’t ride your e-bike for more than 1 week,please remove electric bike battery power connector.