YAMAHA EASY.. Old pedelec ebike but the 24v mid drive unit has potential

[Beach Thorncombe]

Dissection of motor parts to trace wires while in situ seems challenging / impossible at present.

Motor is stamped with "X07 - A0 9 4 S".

Can glean no further info anywhere.



I must focus on main objective of deducing which wires, (from some new battery I might construct with 18650s), would go where, (in relation to the three pins described earlier), and at what voltage?

Either that ... or I'd haver to fully dismantle / remove unit from bike ... (not a prospect I welcome right now) ... especially with that process offering questionable guarantees of resolving the puzzle.

Please help with further suggestions for identifying the mid drive unit / testing the motor / deducing the voltage parameters / offering advice re likely controller / OFF ON ECO voltages.

Thanks.

 

[Beach Thorncombe]

Last, left-field, thought of the morning ...

OK. We know that old fashioned nimh batteries didn't require BMS, (Battery management systems) which suggests there may be scant or zero exotic circuits in the battery pack?

That might mean that there could be only 2 potential voltage factors to consider ... with 12v and 24 volts being the two voltages to ponder.

24 volts connected to the black and red wires?

12 volts connected to the thinner ,controller' wire?

Unless, (unlikely?), a lower voltage 'controller' wire picked up the voltage of just one nimh cell?

That is unlikely ... isn't it? And fiddly and 'more work' and complication during the manufacturing phase?

I'm thinking / writing these thoughts out loud to, perhaps, nudge a reader into, maybe, recalling their own observations while tinkering with similar battery case setups.

Sure. There could be some titchy little electronic circuit in a battery case but ... is there? Has anyone knowledge of the inner workings of a nimh battery (case) setup?

 

[anotherkiwi]

Don't you have a 24V battery handy? I would connect temporarily to the thick black and red and try turning the bike on.

Could the thin red just be used for the LEDs showing the battery level on the handlebar?

I think that maybe you might have to drop the motor to get at a hidden screw for the controller cover if it isn't budging.

 

[flecc]

Hi Beach Thorncombe. I only had a brief passing acquaintance with the original Yamaha PAS model, though all three were very similar. They were only on the UJK market for about three years from 1999 since the Giant Lafree from 2001 on was far more popular with our e-bikers.

However, the Yamaha models were much more popular in France and ran there from 1999 to 2006, so it's likely that there will be much more information available there. So I'd suggest you join the French pedelec forum and ask there:

This is the entry link to join where you accept their terms and conditions by clicking J'accepte:

http://e.bike.free.fr/forum/register.php

That takes you to the page where you enter your details, you'll probably be able to decipher what is wanted to answer each question, but if not use Google Translate or similar or a French-English dictionary to check a word meaning. I've added translations below as a footnote:

The good news is that the page has a drop-down option where you can choose to use English instead of French in your posted questions!

Footnote

The questions in French you need to answer are your name and a password with password confirmation, which I'm sure you can decipher.

Then you are asked these:

Saisissez une adresse de courriel valide, that is your email address.

Then there's an anti-spam question which changes all the time, so ask Google Translate what the question means.

Then there's your time zone which is by default GMT.

Then the French or English language drop-down choice for your postings.

Then there's the choice of whether you want your email address to be shown to others. The three options in this order are in English:

Display your email address.

Hide your e-mail address but allow the form to send email. (This is the default)

Hide your email address and forbid the email sending form.

Finally the last question is whether you are remembered between visits. It's checked by default and they recommend that.

Hope this helps you to find some answers, they have listed forums for some named bikes and also one for "Other Makes" which will include the Yamaha.
.

 

[flecc]

P.S. The third battery connection on NIMH batteries are for the NTC thermistor that's in the NIMH pack. It's not needed when using a lithium battery.
.

 

[Beach Thorncombe]

Hi anotherkiwi,

I had tried connecting 12 v and doing exactly as you said ... but got no response when I turned on.

I was aware that there might have been a low voltage protection circuit and that 12v might not have been enough to even wake the system up ... but I've been rather coy about experimenting with any voltage at all until I had investigated most options prior ... for obvious reasons.

You are correct in suggesting it might be worth having a try with 24v though ... and now, with me being a bit more familiar with things, I guess I could pursue your suggestion ... and, ... possibly ... it might actually burst into life.

So ... OK ... yes. I'll give it a go presently.

The thin red wire won't be for LEDs because the machine has rather basic controls. (See below)

 

[flecc]

See my two posts above your last response.
.

 

[Beach Thorncombe]

Good morning, Flecc

I will pursue the website you kindly provided comprehensive details for and, hopefully, will be able to glean more Yamaha mid drive info.

Thank you for providing the link.

I'd forgotten entirely the 'thing' regarding the thermistor. I had been aware that it was, often, important to change a thermister if recelling with nimh batteries but hadn't realised the third pin fed the thermister.

With that being the case, it would seem I just have a routine, regular two pins to introduce to the battery after all. (That would warrant a great big HURRAY if it was to be the case).

Your P.S, therefore, (and anotherkiwi's nudge to try connecting 24v to the red and black wires), might confirm that all I need do is connect a 24v battery to the correct wires and BINGO! I might find myself the owner of a working mid drive Yamaha Easy!

Have I been looking too deeply into things OR have I been wise to resist tampering and experimenting ... until I had sufficient knowledge to confidently attempt to connect wires? (I would have done the latter ages ago ... but for that third pin ...)

We'll, perhaps, have the answer in the next 45 minutes!

 

[Deleted member 4366]

The LEDs will be under that battery symbol. As Flecc said, the third wire is most likely a thermistor. It could also be a charge wire if the charge socket is remote or an on/off switch wire for the battery if it doesn't have a key-switch in the battery.

The controller will almost certainly have a low voltage control in it.

You can't do anything until you drag the motor controller out into the open. There you can apply 12v directly to the motor wires to test it.

Here's the wiring for an Aprillia enjoy, which is very similar, except it has a 12v tap for the lights, horn and indicators. It has a third wire for the thermistor on both the charge connector and discharge one. I'm not saying that your bike is the same. Never jump to conclusions. Get the controller out in the open.

https://endless-sphere.com/forums/viewtopic.php?f=28&t=18505&start=350

 

[Deleted member 4366]

I'd forgotten entirely the 'thing' regarding the thermistor. I had been aware that it was, often, important to change a thermister if recelling with nimh batteries but hadn't realised the third pin fed the thermister.

With that being the case, it would seem I just have a routine, regular two pins to introduce to the battery after all. (That would warrant a great big HURRAY if it was to be the case).

No. If it is indeed a thermistor (might not be), the controller would be reading the signal on that wire and won't give power unless it sees a value in the correct range.

 

[Beach Thorncombe]

OMG!

Apologies!

The "simple" controller does have LEDs!!!

Red ones!!!!!!!!!!!!

(Haven't attempted to fire up the motor yet and suspect I'll need to turn bike on its back to be able to start the pedals rolling first... but ... watch this space!

 

[Beach Thorncombe]

Ah. OK D8veh. I'll not count my chickens yet then ...

Looking at the diagram now. Thanks for the link ... and the info.

 

[Beach Thorncombe]

Well ... With 24v connected to appropriate pins, (and pedals pedalling), the motor remains serenely quiet ... so, yes, it appears that third pin, (the thin pinkish wire), requires electrical nourishment!!!

But what voltage do we think it requires?

Unless there are faults / failures elsewhere in the system or motor?

 

[Beach Thorncombe]

Incidently ... the LED flashes once a second constantly ... though I have a healthy 24v feeding the machine.

Is the LED flashing some diagnostic comment to me?

 

[Beach Thorncombe]

Also ... Remember? The actual barrel assembly for the lock on the battery back is entirely missing. Is that also an 'ignition' key? Do I need that assembly replaced, (or overridden), to complete some missing circuit?

 

[Beach Thorncombe]

No. The barrel lock thing appears to simply be a mechanical device ...

 

[Beach Thorncombe]

If the third, (thermistor) pin is not required, the 24v powered bike should be functioning ... UNLESS ... I have some actual fault?

 

[Beach Thorncombe]

Just for the record ...

With the bike system receiving 24v IN on the first two pins, the third pin, (thinner pink wire) is sending 5.1v OUT.

 

[Deleted member 4366]

Try grounding it through a 1k resistor. My guess is that there's a pull-up resistor in the controller to stop the voltage floating when nothing is connected. You can probably connect it directly to ground, but the 1K resistor will ensure no damage if it turns out that it's connected directly to the 5v rail in the controller, though I'd say that that's not very likely.

 

[Beach Thorncombe]

Do you think so, D8veh?

I appreciate the thought and follow the logic, (and may try adding a 1K resistor down the line), but I'd really / rather hope to try a few other intuitive things before tinkering or modding what I have got.

For example ... What is the chance of locating an original battery case / box OR sourcing a similar / identical one that might be branded under a different, Giant?) or similar name?

Sure. The tech is 13+ years old but ... are there any contemporary style ebikes, (only half that age), that might still have spare parts / battery cases on a shelf somewhere?

I take your point though, D8veh. I'll, perhaps, give myself 48 hours or so and then consider the resistor option ... if I haven't resolved or sourced a fix.