Unoriginal lithium batteries on an EVT 4000e BLM

[Knallbert]

Hi.
My scooter is an EVT 4000e BLM, European version. Originally it was equipped with lead batteries, but I have replaced these with LiFePO4 batteries from Ping Battery.
Recently I have bought a Canada controller to get more speed, but I run into a problem when installing it.
When I turned the scooter on after replacing the controller the first red LED on the dashboard lit, and I got no response when turning the throttle. According to the user manual this indicates a battery pack breakdown on lithium models. When I reinstalled the old controller everything was working as intended.
The old controller are for lead batteries, and the new for lithium, but they looks the same, and even have the same model number (BLM-0299-2801). But obviously the lithium controller are expecting some signal from the BMS that the lead controller doesn’t need.
Does anybody know how to simulate the missing signal, or to turn this test off in the controller?

 

[dnmun]

no useful info. what is the battery voltage and what is the controller LVC. can you measure the gate voltage on the output mosfets on the ping signalab BMS?

 

[Knallbert]

The battery voltage was 54 volt at the moment, and the voltage range for the controller is 40V to 60V.

I doubt the problem is due to a malfunction in battery or BMS. I have been running the scooter on a daily basis for a week (using the old controller) since my attempt on installing the new one.

 

[dnmun]

i thought that you had built a new lifepo4 pack and used the ping signalab as the BMS. can you measure the gate voltage on the output mosfets of the BMS to see if it is turned on? the mosfet has legs that are gate, drain, source from left to right. measure the voltage between the source and gate. use the 20V DC scale and put the red probe on the gate and the black probe on the source.

 

[Knallbert]

If the problem was malfunction of the batteries or BMS I should have the same problem on both controllers but I only have it on the lithium controller, the lead controller are running without problems. In addition if the battery voltage was to low the first red LED would be flashing, not have a steady light.

There are two reasons why I think this has something to do with the communication between BMS and controller:
- According to the user manual the error message I got (steady light on the first LED / battery pack breakdown) are only for scooters with lithium batteries, i.e. this test are not run on lead batteries.
- The controller doesn’t have enough inputs to monitor all the cells in the battery for a battery pack breakdown it would need an external BMS for this. All it can do is check the total voltage.

In the original configuration there are signal wires going between the BMS and controller, but since I have an unoriginal controller there are no communication between BMS and controller today. The only cables between them are the power cables.

I’m pretty sure that to fix the problem I have to simulate some of the signals going between the original BMS and controller, or change the controller’s setup.

 

[mistercrash]

The specs for the EVT 4000 Lithium says the battery has a voltage of 49.4V. Is that the nominal voltage? That is a weird voltage. Just a shot in the dark here, if you're running with a 15S LiFePO4 battery from Ping and the lithium controller is made for a 13S LiFePO4 battery, there might be a HVC keeping the controller from working at 54V.

 

[dnmun]

just no idea of what he is talking about and no pictures to make sense of it. sounds like he is using two different controllers too.

 

[Knallbert]

Sorry if I hasn’t been clear. I understand the heading can be misleading it’s just that if I had original lithium batteries, and BMS, I wouldn’t have this problem.

I’m trying to upgrade the motor controller on my scooter, so yes I have two different controllers.
Both controllers are original EVT controllers, and made for the motor I got on my scooter.
The controllers are almost identical I suspect the only difference is in firm ware:
- The old controller is for lead batteries, and has a speed restriction.
- The new controller is for lithium batteries, and is unrestricted.

The Ping batteries are an old upgrade. I have been using them for over a year, without any problems, and the scooter is still working flawlessly as long as I use the old controller. The problem is only on the new one.

On both controllers the low voltage cut-off is integrated in the controller.
But the new controller has an additional cut-off function named “Battery pack breakdown”, and this function is causing the problem.
I’m pretty sure the cut-off is triggered by a missing signal from the BMS, but I don’t know on which wire this signal are supposed to be, and shorting random wires to see if it solves the problem doesn’t sound like a good idea.

So what I need is some advice on how to make my new controller work on my scooter without bying original BMS and lithium batteries.

 

[zEEz]

you should really post some pics!

have fun!