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

[Danidl]

Season of good will. (As they say).

I apologise, D8veh …

I might reflect … NO. I do reflect, (and admit), I should not have been so pedantic in reading too much into your ‘wasting time’ comment … and should have just appreciated the sentiment of your observation regarding the simple task of, (hopefully), just getting the job done …

And … forum experts?

Sure. I was posting on the technical forum so should have appreciated that, unlike some social forums I am used to, it would be quite normal to expect ‘matter of fact’ advice, (delivered in a practical way), rather than in emotive, expressive prose!

Yes. I conceed, it was ungracious of me to be so prickly.

I’m sorry …

I must have got out of bed on the wrong side!

John H is yet to furnish me with any resistors and, in another flashback of hindsight, I might have just ordered a few online … because John’s busy schedule has meant he was unable to get to me over the, (past), weekend.

No matter.

I imagine the resolution of the motor test, (either by using forum suggestions or other means), may not happen for a few days but I will report back any progress. (or success), as soon as I have any news to offer. (For the benefit of anyone else addressing similar issues in the future).

I’ve taken on board all the additional suggestions and thoughts posted in the last day or so and the collective mass of that information will, hopefully, eventually get the issue(s) resolved.

I don’t wish to fall out with anyone, (more than I already have), and will endeavour to try my best not to be so precious in the future.

Regards,

Beach x

P.S

Shemozzle. Yes. It would be useful to gain such info re the resistor spec but I'm not sure I'd be brave enough to milk that seller for such information or request they perform such a test!

Danidl. An excellent addition to the thread, especially the positive 'good news' deducing, (hopefully), that the system appears to be healthy in working well enough to even have the LED flashing.

I've absorbed the other points you have raised ... and welcome them.

... and I understand / acknowledge your final sentence.

Like Scrooge, (in a Christmas Carol), I think I have had time to reflect on the error of my ways!

EDIT. Oh. Forgot to add. I used two, (fully charged),12v, deep cycle, SLA's, (in series), to perform the 24v test so would anticipate they were adequate in replicating the power required to emulate the original, (missing) nimh cells. (Battery).

You are a gentleman at heart, Happy Christmas

 

[Beach Thorncombe]

OK, Flecc. I'd appreciate that ... and will pop into two of the several local charity shops in my town tomorrow, (A hospice one and an animal one) and make a donation in a "pay it forward" manner to acknowledge and pass on your own good deed. (I'll mail you, in a minute, with my personal details).

Thank you for that.

I'm pleased you returned to the thread, Danidl, and am warmed by your positive, friendly comment.

Very much appreciated also. x

 

[flecc]

OK, Flecc. I'd appreciate that ...

Going in the post box tonight, but we only have an afternoon collection so will probably be Friday delivery to you first class.

Thank you for the kind donation, my best wishes for Christmas and the New Year to you and yours.
.

 

[Beach Thorncombe]

Brilliant!

Thank you.

Seasonal greetings, Flecc. Wishing you and yours evry happiness for Christmas and the New Year.

 

[shemozzle999]

Hi Beach,

Cheapest German Yamaha Easybattery pack re-celler:

https://translate.google.co.uk/translate?hl=en&sl=de&tl=en&u=http://www.rakuten.de/produkt/vac-akkude-akku-fuer-yamaha-easy-fahrrad-ebike-akkus-24v-90ah-nimh-380030436.html?pt=4&pb=box1

It gives an indication of the internal space available via the cell dimensions if you want to convert to Li-ion / Lipo cells.

p.s.

I believe it is a brushed motor under the plastic top hat and would require a brushed controller if the original is faulty which causes problems as most are only throttle controlled.

 

[Beach Thorncombe]

Another good link, Shemozzle - and a brilliant idea. Thanks.

Yes. I can calculate the physical volume occupied by the nimhs in the photo and construct a DIY 18650 clutch of cells, (to replace them), accordingly.

If any members / readers have already done similar, (or can reveal how many 18650's I might be able squeeze into such a space ... please dont tell me!!

I want the small pleasure of recreating the current nimh battery set up within my favourite 3D drawing / rendering program, (Bryce), and will probably create the model tomorrow evening.

Yes. It is true, I could just measure the physical volume of the battery case inside 30 seconds but, for a hobby and for pleasure, I tend to create and manifest most of my real life projects into my Bryce 3D worlds prior ... just as some folk enjoy assembling traditional jigsaw puzzles!

As for actual cell assembly / battery construction, I'll have a choice to either use, lego like, plastic snap together cell holders from China OR, (by avoiding above mentioned cell holders), may gain extra space by staggering 18650 cells diagonally, (and snugly), before securing with hot glue.

Ideally, I'd seek to squeeze a BMS, (battery management system), card in the space also.

I've generally, in the past, used the chinese cell holders to allow for a little ventalation / cooling around the cells but, on this occasion, (with it being a modest sized experimental cell / battery build), I might opt for the more tightly packed, slightly riskier, (heat wise), diagonal arrangement.

Obviously, the above 3D initiative will only be a theoretical exercise ... to calculate the number of 18650 cells it may be possible to squeeze in, (using various configurations I shall experiment with), but it will also be giving me the potential a/h capacity of any new lithium based setup I might create.

I'm excited actually because I've never experienced, (or ridden), a mid drive crank / gear driven machine before though I do believe the efficiency of such a setup makes up for the, otherwise, modest capacity I could shoehorn into an original battery case.

According to my homework, the Yamaha Easy, (aside from dealing with hills extremely well), is capable, (was capable), of up to 25 miles range ... despite running from 24v and only having a 6 - 8ah nimh battery pack.

I'm hoping the lighter, newer 18650 cell technology I introduce, matches or exceeds those figures.

Most of the hundreds of 18650 cells I possess are recycled from dead or poorly laptops connected with my business although I also have several square / oblong / rectangular gel like lithium cell packs rescued from laptops using that alternative construction method.

I haven't investigated or done my homework as to how best to make batteries using cells like that but they might have some use somewhere also.

I doubt I could safely or robustly connect such gel packs in series or parallel to power a motor but I could use such packs, (descretely hidden), to power USB charging points, (for my cameras and gadgets), my angling night lights and / or cycle lamps.

Incidently. All of the above thoughts and musings are just enjoyable aspects to ponder along the way and, even if I later discover that some of my hopes, ideas ... or expectations ... fail to match my mental mechanations, I, (mostly), enjoy the experience ... and learn from the process.

(Pause)

Back down to earth ...

Actuallly getting the motor running remains the, overall, main objective for the moment.

Without that piece of the jigsaw resolved, there will be no puzzle to complete!

 

[flecc]

According to my homework, the Yamaha Easy, (aside from dealing with hills extremely well), is capable, (was capable), of up to 25 miles range ... despite running from 24v and only having a 6 - 8ah nimh battery pack.

That's reasonable, the Giant Lafree crank drive of the same period delivered 20 miles for most riders from 24 volts 6.5 Ah of NiMh.
.

 

[shemozzle999]

P.S

Shemozzle. Yes. It would be useful to gain such info re the resistor spec but I'm not sure I'd be brave enough to milk that seller for such information or request they perform such a test!

.

You could try and contact the OP in this thread via a Conversation ( PM) as it appears he has a battery and could measure the resistance of the thermistor:

http://www.pedelecs.co.uk/forum/threads/yamaha-easy-battery-re-cell.25278/

 

[Beach Thorncombe]

Good to know, Flecc though, I confess, I think that any lithium based battery replacement project, (using the original battery case), is not going to deliver me any significant improvement over the original setup, (capacity wise), though the new system may save me a few grams in weight.

This revelation doesn't actually matter because I will still be delighted to have bought a classic, early mid drive crank geared pedelec, (capable of 20+ miles range), for the princely sum of just £35!

While older tech, the nimh's populate the case virtually entirely, (as far as my Bryce 3D modelling exercise is concerned), whereas, the newer but 2nd hand tech of the 18650s currently only allow me a 7S2P arrangement ... with space to spare ... though, as I write, not enough space to squeeze in a further 7 cells to up the capacity via a 7S3P arrangement.

Just For Fun

The following is just me playing.

I can make lithium based battery packs to suit any and every occasion and don’t normally need to compromise myself by having to work to within specific sizes or dimensions but, for fun, I’m taking the info Shemozzle provided in the link above and am attempting to design the best, most efficient, (space wise), cell deployment that the battery case of the Yamaha Easy would offer.

Here’s a 3D pic representing the challenge in hand.



A. Original image showing 20 cell nimh Yamaha battery from Shemozzle’s link. B. My own 3D object representing that image of the nimh pack. C. An nimh C cell and an 18650 cell for size comparison. D. Depiction of Chinese ‘lego style’ cell holder complete with ONE 18650 cell installed. E. An arrangement of NINETEEN 18650 cells capable, collectively, of being accommodated within the original battery case.

Size

Chinese cell holders are far too space hungry! As can be seen, object D, the chinese cell holder, (complete with one green 18650 for comparison), shows that only 10 18650s could be fitted upright in such a space.

I’ll need to gain space by staggering cells, as depicted in object E, to ensure I achieve a diagonal, space efficient, arrangement. As you can see in object E, (if my 3D depiction is accurate), I can fit 19 18650 cells in the same space as the 20 x nimh C type batteries occupying the original case.

Thing is … 19 cells would only make a 7 series, 2 parallel, (7S2P), 24v battery setup – with space for 5, (not 7), cells left over. Such an arrangement would only deliver me 4ah based on my collection of recycled cells averaging 2000mah each. (Not acceptable).



Original nimh arrangement on left. Space hungry cell holder option in middle. (Accomodates only 10 upright 18650s). More compact staggered 18650s arrangment on right. (17 of 19 cells visible - with 2 tucked below).

However, having created the 3D model, I can play with certain perimeters and experiment and attempt to sneak a further couple of cells into the assembly, hopefully then being able to achieve the 7S3P battery setup that would, (given the size constraints), deliver 6ah like the original nimh once delivered.

Here's what I've come up with.



I settled for removing the two fatter 18650 cells lying under the main pack of cells and replacing them with three thinner but taller 17670 cells PLUS I think I can squeeze a further 17670 cell in the middle band of 18650s in the main pack. (17670 cells highlighted in yellow).

This will acheive the 7S3P ... or will it?

Thing is ... will the 17670 cells, (often used instead of 18650s within laptops), be compatible and happy being surrounded by 18650? And will they take a charge the same way and be protected by the BMS. (Rhetorical question I ask myself)

Such an arrangement makes the best use of space available, gives me the 7S3P capacity I seek and also allows room for a BMS motherboard to lay in the bottom of the battery holder.

PING!

A penny has just dropped! If there were problems with my percieved solution, (mixing lithium cell types), I guess I could construct a whole battery using those slimmer, taller 17670 cells and definitely fit more in and up the overall capacity despite the limited space available.

OK. Yes. Perhaps the 17670s specs hold a charge / voltage / resting characteristic different than 18650s? Stuck here completing this, I can't look online to check at the mo but I'd be grateful for information confirming or dismissing the fact that I can, (or shouldn't), mix the two types.

Your thoughts are welcome ...

Hi Shemozzle. For the moment, I'm happy to wait for Fleccs envelope to arrive. It will contain the resistors he has gifted me. I will then try the method that D8veh recommended. (Installing the 1K resistor ... and trying a 10K one if the 1K resistor doesn't do anything).

I won't bother anyone else before Christmas but may follow up your suggestion in the New Year if still wrestling with the task of getting the motor running.

(Hopefully, I won't have to).

 

[D8ve]

The crank drive makes up for some of the issues in low power hub drives when near stalling the efficiency rapidly drops so power disappears as heat without speed. The crank setup avoids this. And new hubs use more power to stay in a more efficient zone meaning more range less heat.
It's a nice bike though.

 

[Beach Thorncombe]

Hi D8ve,

Yep. I understand that crank driven machines utilising the gears, aids the motor in running very efficiently.

I'm looking forward to riding the Yamaha.

Oh. Guess what I've just found in one of my outbuildings?

a 24v nimh battery pack. Well ... the cells that make up the pack.

I collected a wheelbarrow load of old drill packs and other recycled batteries from my recycle centre last year and ... when I went out, (just now), to find an old nimh cell to measure to enable me to add it to the 3D drawings, (above), I came across this.

A 24v pack ... with a thick red wire, a thick black wire and a thinner (thermistor) wire!



24v. 20 x nimh cells. Just like the arrangement of the official Yamaha Easy battery ... though in a squarer format.

Red wire is on left. Black wire is on right ... with thermistor wire in middle.

There must be some way I can use this thing. Right?

Apparently, unless I had the official charger for it, any alternate charger would need its thermistor changed to match the battery, (or was it the other way round?) ... Advice I recall from elsewhere ... though, goodness knows why I remembered that!

Does anyone know any 'bush repair' that might get the cells charged ... without me dismantling / unconnecting the cells? (I have the self harming urge to just introduce the two 12v lines to a 12v car battery charger ... for 45 minutes or so ... but I'm sure it isn't that easy, is it?)

OR ... I have an Imax B6 charger, That thing is intelligent and always knows what lithium cells it is connected to.

Would an Imax B6 help me?

It would be fantastic to be able to charge this block of cells. It would give me a Plan B style alternative method of tinkering with things!

I'm being light hearted. I'm not suggesting we divert attention or dilute the thrust of the thread by going down this particular rabbit hole but ... well ... who knows ... if I sent out a search party, I might even find the charger this thing plugs into!

 

[shemozzle999]

Or a pouch cell solution:

https://www.alibaba.com/product-detail/lithium-polymer-battery-cell-3-7V_512737659.html

 

[Beach Thorncombe]

Hi Shemozzle,

The real issue is the business of actually getting this mid drive unit tested ... to see if it even works at all.

I'll make my own, permanent, battery / batteries for the machine once I have established it is a runner.

I doubt I would ever purchase cells / batteries made up already ... not when I get so much pleasure making my own.

 

[Beach Thorncombe]

Have now also found a couple of, (nearly new), unused 5ah/20hr SLA's that were never used on a Chinese folder I tinkered with before getting my first proper ebike back in 2013.

Funny enough. Sizewise, the footprint of those two 5ah SLA batteries look almost the same size as the original Yamaha Easy's battery pack.

If the 1K / 10K resistor does its job, at least I could hook up the two SLAs and, (probably), get 15 miles range out of the Easy while testing it.

... AND, with Fleccs confirmation that 6ah capacity should do approx 20 miles, (at least), if all goes well, I could knock up a 14a - 18ah lithium pack and create myself a 'long distance' pedelec machine capable of 60 - 70 miles or more subject to rider input, economy mode, an organised route ... and a fair wind.

Ha ha. I've now loaded so much into the anticipation of getting this thing working!!!

 

[Beach Thorncombe]

I've located a charger for a 24v nimh pack. I'm not recommending this particular link or product but adding the link here just for reference.

http://www.powerstream.com/nimh-pst-n100-24v.htm

(Personally, if I need such a product, I'd source a similar unit for a quarter the price in China).

 

[flecc]

I've located a charger for a 24v nimh pack. I'm not recommending this particular link or product but adding the link here just for reference.

http://www.powerstream.com/nimh-pst-n100-24v.htm

(Personally, if I need such a product, I'd source a similar unit for a quarter the price in China).

I can recommend these having bought them, as have other pedelecs members. The original Panasonic charger supplied with the Giant Lafree NiMh bikes suffered many failures and this was a better replacement. In addition its thermistor was the correct value for the Lafree, being 10k, B = 3950.
.

 

[Beach Thorncombe]

Success

... I think!

Within minutes of Flecc's envelope arriving, I had installed one of its contents, (a 1K resister), across the required terminals and connected a fully charged 24v SLA battery.

On switching on, the first thing I noticed was a series of 3 bright red leds that lit up, acting as a battery meter. However, hand turning the pedals while lifting the bike off the ground did nothing. The motor did not engage.

Instinctively, I mounted the machine, applied pressure by pedalling properly ... and immediately found myself travelling across the studio floor under power.

A very subtle layer of power but power, none the less.

It works!

Disconcerting

The power delivery experience is alien and new to me*. I have to pedal to be rewarded with assistance and, on the flat, such assistance is, again, extremely, subtle. I mean; Yes. I feel the additional energy of the motor assisting but, really, it appears ... underwhelming.

* EDIT. I say new but my Powabyke Euros have a similar PAS. What I really mean is ... the Yamaha Easy appears far more 'needy', requiring pedal power from a rider constantly before offering any reciprocated matching power.

This feeling ... this disappointment could be more to do with my inexperience in handling a true PAS pedelec rather than any failing on the machine's part ... so I'll resist offering a view ... until I have a true view!

I'm cycling along the flat now, planning to travel down to my local (East) beach at Bridport Harbour, West Bay, (where Reggie Perrin, Harbour Lights and Broadchurch were filmed) BUT ... on approaching a test hill, (it starts easy but steepens quickly), my heart is not happy with the level of excursion the machine seems to need to navigate it. (I had a scare in the Spring and don't wish to, unexpectedly, put my body under more strain than needed).

Stupidly, I realise I was in 4th gear ... but changing down doesn't help that much.

I abandon the hill test ... giving in to waves of anxiety.

This can't be right, I muse to myself. This machine is supposed to be able to eat steep hills!

Again. I refer to my own inexperience.

Best thing I can do is abandon the test and return to the forum with these thoughts.

Incidently, ECO mode appeared to do nothing but, (It was windy, wet and miserable), perhaps, in different, calmer, circumstances, I might feel ECO mode kicking in ... if it even does!

SO ...

a) Is it merely a case of me not understanding the way the pedelec mid drive system works?

b) Is it true? You have to be exerting about the same energy you might exert in pedalling a normal bike ... to get the assistance?

c) Is it possible some part of the control system is failing or faulty?

OR

d) Should I appreciate I was testing a machine nearly 20 years old?

Final thought.

If this machine is working just fine, I confess I might actually like the way it delivers power ... in the summer ... when I tend to be engaged in more angling, walking, cycling and general keep fit because, it appears, this pedelec offers a genuine 50 / 50 partnership where it delivers about the same energy from its battery / motor as a rider may be excerting.

Fine ... and, being a tall, 700c wheeled bike, I feel it elegantly sails down the road as well.

So ... as a, kind of gym machine on wheels, it would keep somebody fit ... while offering a certain assistance.

Guess I was surprised though.

I imagined it being more of a hill climber.

Are modern Bafang crank drive units like my Yamaha Easy? Do they work in a similar way?

Thing is ... before I found the £35 mid driven Easy, I had been considering purchasing a Bafang unit.

I'm not knocking the Easy. It does pick up and support a rider ... on the flat but, hills wise?

Not so sure.

Unless it is just me! :-(

 

[Beach Thorncombe]

I can recommend these having bought them, as have other pedelecs members. The original Panasonic charger supplied with the Giant Lafree NiMh bikes suffered many failures and this was a better replacement. In addition its thermistor was the correct value for the Lafree, being 10k, B = 3950.
.

Ah. That's good to know, Flecc. That means that IF I were to renovate my, (or any other), set of 20 nimh cells, I could use that charger.

Thanks for the reassurance. It may yet become an option.

 

[Beach Thorncombe]

Thanks to all Pedelec forum members who contributed to this thread.

 

[Deleted member 4366]

You have to do hills in first gear to get the necessary torque.