Battery not recognized on my EasyMotion Evo Street

woodenski

New Member
I have an EasyMotion Evo Street urban electric bike - 2015-2016. Until a few days ago, it as has worked perfectly.

Now, when I turn on the handlebar controller, it starts up normally, but shows the battery at zero level. In this state, I don't get any pedal assist, and cannot change the pedal assist from anything but 1.

The battery seems to be charging normally, the lights on the charger operate normally. On the battery itself, pushing the battery test button shows five green lights.

So, I think the battery is okay, something in the cables or controller is not working right.

I have carefully wiped all the contacts that I can find. I have unplugged and replugged all the cable connections from the handlebars.

Anyone have any suggestions for me?
 

J.R.

Well-Known Member
You're going to have to check the battery with a volt meter first. My first thought, by your description, is possibly the BMS (battery management system) within the battery might be faulty and not allowing current to flow to the bike.

When a battery is very low, 5 or 7% the only assist the bike and battery allow is PAS 1. But you should get assist in level one unless the BMS is telling the bike your battery is at zero %. In which case the bike would still go into PAS 1, but you would get no assist. If the lights on the battery show full and using a volt meter shows a low voltage, something like 42v for a 48v battery or 28v for a 36v battery (I can't remember the exact number, but in that range) the low voltage cutoff would be tripped to protect the battery. It also could be the 5 year old battery just doesn't hold enough current anymore. The confusing thing with that is the 5 LED are lit. That's why I think it might be the BMS. It doesn't sound like the controller.

You don't mention the condition of the battery. Miles, use, how well you took care of it. Did it sit for long periods at full charge or low charge. Both are bad for a pack. I have a 5 year old BH battery that performs well.
 

woodenski

New Member
The battery was probably not stored too well. I inherited the bike from a friend. The bike has only a few hundred miles.

I will see if I can find a friend who can help with the multimeter too check the battery voltage.

I think I may have found a potential issue. The plug section on the battery is very loose, and moves around. Like the mount inside the battery is broken. This is probably stopping it from getting a good connection with the charging plug. So it may not be charging properly.

Thanks for the reply, will keep working.
 

dcasali

New Member
I have an EasyMotion Evo Street urban electric bike - 2015-2016. Until a few days ago, it as has worked perfectly.

Now, when I turn on the handlebar controller, it starts up normally, but shows the battery at zero level. In this state, I don't get any pedal assist, and cannot change the pedal assist from anything but 1.

The battery seems to be charging normally, the lights on the charger operate normally. On the battery itself, pushing the battery test button shows five green lights.

So, I think the battery is okay, something in the cables or controller is not working right.

I have carefully wiped all the contacts that I can find. I have unplugged and replugged all the cable connections from the handlebars.

Anyone have any suggestions for me?


By coincidence, I just dealt with this problem on a friends EVO, which had a BH-03 48V battery that self reported (pushing the battery charge level button) that it was charged, yet when connected to his bike would only light up the display which reported 0% charge — and ain’t goin’ nowhere.

Friend‘s wife had an identical bike which made it easy to determine the problem was with the battery (it didn’t work on her bike; hers worked on his bike).

Measuring the battery voltage gave 54V (full charge) and I was able to power a load (100W bulb) for more than an hour, which reduced the charge by 1 battery indicator level. Charger charged it back up. I opened the battery and reset the BMS by disconnecting the battery Negative connection to the board and reconnecting it. (Don’t do this unless you have a charger on hand; I had to connect it to his charger to get the BMS back online.)

All to no avail when I put the battery back on the bike. Display reports 0%; bike no go.

So, to the Internet. I learned that If you examine the EVO battery connector you will find two large brass blades, which are battery positive and negative. There are also five small pins which mate with five ~1/8” round flat pads on the bike side of the connector. Four of them are mysteries and have insignificant voltage on them. The fifth one, which is closest to the negative battery terminal, is the key. It has a voltage proportional to the charge level. On my friends battery, it read a bit over 9V at full charge; around 5V at level 3 charge.

The display controller does not measure the actual battery voltage; instead it uses the voltage on this fifth pin to determine % of charge. IF THAT PIN DOESN’T HAVE A VOLTAGE ON IT, OR DOESN’T PROPERLY PRESS AGAINST THE CORRESPONDING BIKE CONNECTOR PAD, YOUR DISPLAY WILL ASSUME YOU HAVE 0% CHARGE AND REFUSE TO ENABLE THE MOTOR. In our case it was a pad to pin issue.

I found that if I pressed down on the battery and wiggled it slightly, the display would go from 0% to actual, and the bike would operate normally.

The pin to pad connection is flimsy as hell, and I’m not sure how we are going to effect a permanent fix. A replacement connector would be great, but... Open to suggestions. It has occurred to me that a simple voltage divider (two resistors in series of appropriate value) could be placed on the display side of the circuit and create approximately the same values as the pin now reports.

So, my guess is your battery and BMS are fine; your connector, like ours, has issues.
 

woodenski

New Member
I think your diagnosis was 100% correct with the small pins.

My issue was slightly different, but exactly the same symptoms. On my battery, the plug unit had broken free from its mounts. So, it was floating around a bit in the batter unit. With the charger, I was able to plug in okay, so it was charged. But on the bike the brass blades and the pins didn't contact adequately. So it would power up, but not show any charge.

I cracked the case of the battery, disassembled the wire harness and circuit board so I could reach the plug. I tack glued it in place with superglue. Triple checked that is was aligned property, then epoxied and silicone glued it in place as well as a I could. I used two types of glue on different parts, as I was not sure which glue would work best on the plastic.

The bike works great, and the plug socket seems very solidly attached again.

Thank you for you guidance on this.

I recall on some of my old electronic projects, we used something called conducting gel. I was supposed to make for better connections. Maybe a dab of that on top of each pin would help the connection be more reliable.
 
I want to thank the folks on this thread for probably helping to fix my Lynx 6 Pro. I've been having occasional problems with the motor cutting out after a pedal strike or a compression dip in the trail - the motor would stop but the display stayed on. I am a little afraid to say it out loud, but I think it is fixed after doing three things
- cleaning the five little pins and their corresponding locations on the battery with a pencil eraser,
- adding a little dielectric grease to the contacts and
- using a small piece of plastic from a hard clam shell package as a shim underneath the contacts to push them tighter against the battery.

So far I have ridden three times for about 40 miles (singletrack) and it hasn't cut out yet. Prior to seeing this thread it would have cut out half a dozen times over that many miles. I'm keeping my fingers crossed.

BTW, the piece of plastic I used is probably about 1/32nd of an inch thick or maybe as thick as 1/16th inch. Just find something around the house that comes in that hard plastic that you have to use a razor knife to open.
 

Ebiker01

Well-Known Member
The pin to pad connection is flimsy
Have to unscrew those 2 screws that are holding the part with the 5pins , then underneath, fix the wires in such a way that they are around and not obstructing that part from underneath.

If the wires are directly underneath , the pins won't retract properly or maybe only 70% , or maybe only when reading Ebr😉...joking.
With the wiring under and not properly spaced out they will be hard to move UP/DOWN.

And fix the wires in such a way that they do not move under vibration stressors.

The pins should retract easily when pressing on each one of them with something(small plastic tool).

In the working situation, they should be fully UP, and when the pad of the bike connector contacts them , they may retract slightly but just enough to still touch.
If it's a wire obstruction, once touched by the pad they may retract too much and loose contact.

And then your ESpaceship 🚀 , won't function. So, fix those wires and then it will work.
 
I loosened those two screws with the intent to put a washer under each one but could not find a thin enough washer so I used a piece of plastic packaging cut to shape and size. It seemed to me that the pins need to protrude more to ensure that they contact the battery connection more firmly, that's why I shimmed the five pin connector.