First E bike A2B need help.

[Gwest]

Hi Everyone: first post, I decided to buy a A2B Metro and get my feet wet in the E-Bike community.

I bought a used A2B Metro from a Guy for $300 and he said the thing just Quit. No other info other then it just stoped running.

I got her plugged in and charging. I wanted to ask what’s the first thing you guys Recomend testing. Thanks for your reply’s in advance.

 

[amberwolf]

Wires and connections are the most common failures of any system.

After that, the batteries and/or BMS. There's several A2B threads that discuss the batteries (and other systems).

If yours is one with the Ultramotor hubmotor with internal controller, that could've failed. (see my Stromer Mountain 33 hacking thread for how to wire it up for an external controller instead, if so).

Could even just be an ebrake lever switch that's stuck "on".

 

[Gwest]

I will try to post a pic.
Yes it has the Stock UltraMotor hub motor.

 

[markz]

Internal controllers are not good to have.

$300 is a great deal for an A2B! Something simple is all it is, more then likely.

 

[Gwest]

Thanks for the Reply:
What would be your recommendation first steps in trouble shooting.

 

[E-Glider]

Thanks for the Reply:
What would be your recommendation first steps in trouble shooting.

As you are new to messing around with E-bikes, simplicity is best!

1). Charge battery and see if it holds a charge OK.

2). Check tighness & fit of main power connections to motor.
These are 'bullet' type connectors.
One in the wires from the battery to the motor - positioned under the rear wheel frame arm and a couple under the plastic frame-cover where the battery is.

3). Check throttle cable connector too - in similar position under rear frame arm.

4). Check fuse - usually a 40A unit - in relay switch box under same plasitc cover below in-frame battery.

5). When you turn frame key switch to 'A' you should hear a little 'click' noise as that relay switch engages.. of no 'click' then either the switch or the relay or the battery or the connectors may be faulty.

6). If you can source a separate 36v DC supply, disconnect the connector to the motor under the rear frame arm and connect your 36v supply, with correct polarity, directly there. That should tell you whether the motor works or not anyway?

Let us know how you progress initially anyhow.

 

[wturber]

Wires and connections are the most common failures of any system.

While not specific to ebikes, my years in telephone/communications installation and repair showed the same thing. Failed or marginal wiring and connections of various sorts dominate as causes.

I've only trouble shot one failed ebike and that turned out to be wires that had corroded internally due to poor storage conditions. Everything "looked" good, and the bike sorta worked but would cut out under load. The wiring tested fine under simple continuity testing, but the corrosion kept it from passing the full current needed.

Anyway, given the number of possible fail points on an ebike and that an ebike is subject to a lot of vibration and weather, wiring should be a good place to start once you've established basics like that the battery is holding a charge and delivering a proper voltage.

 

[fechter]

On my A2B, I had one of the bullet connectors for the main battery fail. These are prone to getting loose. You have to turn it over and take off the cover under the bottom bracket to access. I unplugged mine and used a pliers to slightly squeeze the female part to make it tighter and plugged it back in.

Also won't hurt to unplug the connectors going to the motor and plug them back in.

See attached service manual. Look at page 7-1, it shows the connectors. It won't hurt to unplug and reconnect all of them. See if they feel tight and look at the contacts.

 

[E-HP]

On my A2B, I had one of the bullet connectors for the main battery fail. These are prone to getting loose. You have to turn it over and take off the cover under the bottom bracket to access. I unplugged mine and used a pliers to slightly squeeze the female part to make it tighter and plugged it back in.

Also won't hurt to unplug the connectors going to the motor and plug them back in.

See attached service manual. Look at page 7-1, it shows the connectors. It won't hurt to unplug and reconnect all of them. See if they feel tight and look at the contacts.

After a couple of these loose connection trouble shooting issues, I started using Deoxit on all of my connectors, hoping to avoid future issues. I don't see it mentioned much on the forum, but it might be helpful for cleaning up the contacts and then preventing future problems.

 

[wturber]

After a couple of these loose connection trouble shooting issues, I started using Deoxit on all of my connectors, hoping to avoid future issues. I don't see it mentioned much on the forum, but it might be helpful for cleaning up the contacts and then preventing future problems.

I've used that on low voltage stuff like marginal/intermittent micro USB connectors and it works very well. Haven't used it on any ebike stuff though. But for the lower voltage stuff it would be worth looking into. For the higher voltage power stuff I would think that normal cleaning methods would be more than adequate.

 

[E-HP]

I've used that on low voltage stuff like marginal/intermittent micro USB connectors and it works very well. Haven't used it on any ebike stuff though. But for the lower voltage stuff it would be worth looking into. For the higher voltage power stuff I would think that normal cleaning methods would be more than adequate.
[/quote]

Yup, definitely for cleaning a good scrubbing works best, but just to keep any oxidation building up over time is where it might provide benefit. Might be good for throttles as well.

 

[Gwest]

Hey Thanks for the reply’s. I took the battery out of the bike. To test it any take a look around. All the connections seem good. I do have some De-Ox and can try that.

So the battery has 38vts.
When I turn the Key from Off to (A) or (B)I get no click or sound or lights Nothing?

What should I check next?

 

[2WheelsMovesTheSoul]

Look at page 7-1 of the manual.

That relay control box should be clicking when you turn the key. The 2 big square bits. Put a finger on each of them and try the key.

 

[fechter]

There's a fuse in there somewhere. Also the key switch wire could be loose. The key switch pulls out.

 

[E-Glider]

Position 'B' on the frame switch key is for activating an auxilliary rear battery pack only.

You may need long nose pliers to extract & check the 40A blade fuse on the relay board.

If all connections etc appear good, I would next suspect the BMS board - there may also be a 'reset' button there, I can't accurately recall?

Also worth trying @ 6). above.
x3 12v DC batteries wired in series to give you 36v.. if the wheel turns, at least your moral will be boosted!

 

[fechter]

No reset button as far as I know.

Another test is to try measuring the battery voltage while turning on the key (position A). Sometimes you can measure voltage on the battery when the BMS is tripped but it drops to zero with a load.

 

[Gwest]

Well early trouble shooting.
The 40 Amp fuse on the Controller is good.
The Fuse that’s on the BMS board is good.

I need to test the Key Switch and the Brake switches next. Question If I need a new key switch for this bike where can I get one? Thanks

 

[Hillhater]

What age is this bike ?
There are various versions....early ones had the controller in the motor, with a 2 wire (+ve, -ve) 36 v connection to the hub.....later ones the controller is in the frame with the relays, and there are 3 phase wires to the hub.
Simple to see the difference , but some of E-gliders checks (above) only work on the early models.

 

[Gwest]

Im not sure what year my bike is. But my bike has a 2 connections 1 is a 2 Wire battery connection coming from the hub to the switch module And a round 4 pin connector coming from the hub to again the “switch module” located where the battery is.
To better help identify my bike here is
My serial # is F909F223

P.S anyone know why the photos I’m loading don’t show up?

 

[Gwest]

Hillhater: after re reading your post, I’m guessing I have a later modle with the controller in the frame.
I’m guessing that’s what it is. All my connections from the hub connect to the black box with the Realys your talking about. This is the same black box that holds the 40amp blade fuse.

 

[Hillhater]

I suspect you have the original version with the motor controller in the hub.
The clue is the “2wire” power cable to the hub.
With the power on check that cable connector to see if you have 36v coming from the “frame” area going to the hub.
If no voltage there,..go back and work through E-Gliders check list above .

 

[E-Glider]

I need to test the Key Switch and the Brake switches next. Question If I need a new key switch for this bike where can I get one? Thanks

Well done so far!

The round 4-pin connector is your throttle feed to the in-hub controller.

Hopefully cleaning/tweaking switches/connectors etc works for you.

Re. new replacement Key Switches, if you do need one, it depends if you are keen to keep the machine in 'original' condition or not. If so, you could try contacting: <danial.morris@heroeco.com>
Hero Eco Ltd,
Unit 16, Bessemer Industrial Park,
250 Milkwood Road,
London SE24 0HG.
He successfully tracked down an orig frame switch for me in Germany last year, which was then shipped to a local dealer here in Aus.

Otherwise, almost any generic/2nd hand orig 'on/off/on' key switch would probably get you out of trouble if you can secure it in the existing frame-hole OK:
https://electricscooterparts.com/keyswitches.html
Obviously, if you do not ever intend to fit a 2nd rear battery pack, then a simple 'on/off' key switch would also suffice.

Yes, those brake switches can be 'pesky'!
Again, if you want to keep it original, here is a complete (RH) unit on eBay atm:
https://www.ebay.com/itm/A2B-Metro-Right-Brake-lever/183782274351?hash=item2aca46f52f:g:kNAAAOSw0SJbAOQq&frcectupt=true
- (Probably the actual switch, if you do need it, would fit either your LH or RH lever assy?).

Otherwise, a suitable generic or 2nd hand A2B brake lever/switch unit would get you going if nec.

Hope this helps a bit, should you require this course of action.

(Edit: Maybe the pictures you tried to post here were too 'large' - there seems to be an upload size limit of around 0.5Mb?)

 

[E-Glider]

PS.

No reset button as far as I know.

You are probably quite correct - as is usual!

- I only took a quick look at my original dead frame batt/BMS before replacing the whole lot with Lipo packs & external 'smart' charger/balancer etc.

However, this is the 'button' I alluded to:

Do you know, out of interest, what it's purpose/function actually is then please?

 

[fechter]

Do you know, out of interest, what it's purpose/function actually is then please?

I've never noticed that before. Could be a reset button. I think I have a BMS board lying around somewhere I can take a look at to see if it's the same.

Another test for OP is to pull the key switch out of the hole and see if there is voltage across the wires when it's turned off. I've never had to replace a key switch, but if I did, I think I would just use a standard DPDT toggle switch with on-off-on configuration in series with a SPST key switch which is readily available. Key would just kill the B+ going to the switch.

 

[2WheelsMovesTheSoul]

My old Gen. 1 Metro BMS has that same little button. Not sure what it does.

Still have a box of old metro parts if you need some replacements. Converted motor with Honeywell halls and FF. Original "in wheel" controller, BMS, charger, relay box and a few other bits.