A2B Metro - Constantly shows Low Battery

[Lr_defender]

Hello

I'm new here as I've just come by my first electric bike. It's an A2B metro gen 2 16" wheels with key switch / speedo on the handlebars . I got it as a project as it wasn't running - and still isn't !

Issue is that when powered up the bike runs through startup on the screen as you would expect, but then the orange low battery light comes up along with one flashing block on the battery meter. I've read the low battery section in the gen 2 manual, and have tried the bike with 2 non- genuine batteries both reading 37-38 volts.

As I cant find a gen 2 service manual anywhere, I've used the Service manual from the gen 1 to label / check the wiring as best I can given the gen1/2 wiring differences , check the brake switches, ignition switch, relays etc which all seem good but no joy. Lights work !

I've checked/cleaned /labelled all the connections and retested to no avail. I reached out to A2B who suggested checking connections and also asked for photos as and I quote "The state of charge wiring on the Metro went through some changes over the years and adds to the complication." Any ideas what they mean by that ?

"Rats Nest of cables " thats precisely what had happened to the bike - It must have been stored in a rodent infested shed as the EPOCH grip shift rubber, cable casings and in some instances the cable itself on the rear light, motor and torque sensor had all been nibbled, so i soldered in new sections of wire where appropriate.

As for battery, the Bike didn't have either the A or B pack with it. I am temporarily having to use a lead acid pack that I cobbled together which is holding a steady 38 volts, If I can establish that the motor runs well then I dont mind spending more on it for a proper battery . When I got the bike, the vendor demonstrated the fault using an 18650 pack (showing 40 volts) from his other bike.

Is there a way that I can test the motor directly to prove it runs ? there are so many connections in the motor 3 phase socket and then at least I'd know that my efforts were worth continuing with !

Any suggestions gratefully received !

 

[Deleted member 4366]

I have it at the back of my mind that Ultramotor used CANBUS in that battery, in which case, you can't use an alternative one. To confirm that, you need to follow the wire from the battery connector to see how many cables are in it. If it's only 2, you can use any battery, but if there's more than 2, you'd need to replace all the electrical components except the motor. Try sending a message to member Pdarnett. He did some interesting modifications to a bike like yours and he knows how they work.

 

[Lr_defender]

I have it at the back of my mind that Ultramotor used CANBUS in that battery, in which case, you can't use an alternative one. To confirm that, you need to follow the wire from the battery connector to see how many cables are in it. If it's only 2, you can use any battery, but if there's more than 2, you'd need to replace all the electrical components except the motor. Try sending a message to member Pdarnett. He did some interesting modifications to a bike like yours and he knows how they work.

Thanks d8veh - Unfortunately I dont have either original Battery pack to examine for connections. Power Connectors on the Switch module side only have 2 12awg wires. The lead running to the B Battery pack connector does appear to have 2 additional wires (yellow orange in pic) going to it that i cannot identify from the limited pics /diagrams I've managed to locate.

I have managed to find an EU ultramotor controller diagram (page 2 attached) which shows a female display connector (Top left) which includes at position 20 an 41V-31V SOC (State Of Charge) signal port but dont know if decision that the battery is low voltage is being made by the controller or is being made in the display ? If I was to test the socket what do people think I would expect to find ? is there any way I can use this to fool the bike into running ?