Controller or battery issue

[Matt hignett]

Hi all,

Firstly, as a newbie to the site I’d like to say what a wonderful community and resource this is! I wish I had found the forum/website a few years ago after getting my offroad handbike converted by ‘electric bike conversions’.

To give some background information action. I have a handbike And as I’m a full time wheelchair user, struggled to cover any significant distance. After the conversion it’s given me the opportunity of cycling around with friends and family exploring the British countryside. With Coronavirus taking grip it has been a lifeline to get some daily exercise outside.

Unfortunately around two weeks ago an intermittent issue arose whereby there was a complete loss of power either under throttle or whilst pedal assist was active. The LCD display would go blank and a ‘power switch on‘ was necessary. Sometimes this would last another minute or two, Sometimes significantly less. Occasionally I could even run just off throttle for a couple of minutes before another shutdown. My initial thought was an overheating issue but the controller doesn‘t feel ridiculously hot. As far as I can tell, the battery life is around the same as when first purchased and unlikely to have seen more than 350 charges in its lifetime. The conversion company is longer in existence and I'm unsure If it’s worthwhile purchasing a new battery from, for example ebay, or if I should attempt find a suitable controller to replace the current one. I believe the current controller in a Lishui but I am by no means certain. After spending some time no wires from the controller look damaged. I have not opened the controller box open as of yet

I was hopeful on drawing on the knowledgebase you all have, if the intermittent issue is likely to be a controller, battery or both? If it’s worthwhile trying to acquire a like for like controller or upgrade (if so what to), and generally any sound advice.

attached is photos of the controller box, lcd, battery and motor. Hopefully you guys can help!

 

[Nealh]

Powering off is a battery connection issue if it occurs without assistance, with assistance it is usually battery or controller at fault.
If the fault occurred straight away with PAS I would suspect controller as
yours is the latter whilst In use I would presume battery. Charge the battery and check the output/discharge voltage with a meter directly after charging and at rest a few hours later dependent on the value of the reading we can suggest possible tests to see if the battery is at fault.

 

[Matt hignett]

Powering off is a battery connection issue if it occurs without assistance, with assistance it is usually battery or controller at fault.
If the fault occurred straight away with PAS I would suspect controller as
yours is the latter whilst In use I would presume battery. Charge the battery and check the output/discharge voltage with a meter directly after charging and at rest a few hours later dependent on the value of the reading we can suggest possible tests to see if the battery is at fault.

Hi Nealh,

thanks for the response, excuse my ignorance but what do you mean by PAS?

the power shut off occurs when using the throttle and/or when pedalling. When pedalling it may take longer before the first power loss than when just using throttle.
I’ll charge the battery and run the tests as I have a multimeter to hand Then report back.
thanks!

 

[Nealh]

PAS = Pedal assist sensor. I assume although a hand bike a PAS set up will still be used as well as the throttle.
With PAS use what assistance level do you use when it cuts out ?

 

[Matt hignett]

PAS = Pedal assist sensor. I assume although a hand bike a PAS set up will still be used as well as the throttle.
With PAS use what assistance level do you use when it cuts out ?

Ah thanks for the explanation. Yes indeed it has a PAS setup as well as throttle. I never take the assistance level out of level 1 (of 5). If I do it’s maybe once a month just for 30 seconds to see if it’s still working. just waiting for the battery to charge before getting some readings. In fairness I’m happy to buy a new battery and controller if they can be sourced in the UK. The money aspect isn’t of concern as I’m a avid mtb rider albeit on the handbike.
thanks for the assistance!

 

[Nealh]

Level 1 is low current draw so if the battery cut's out at that level then it is in poor shape,

 

[Matt hignett]

That

Level 1 is low current draw so if the battery cut's out at that level then it is in poor shape,

that‘s really interesting as the lcd screen frequently (and always has done) displays 700/ 750w when in assist level 1 going uphill. Albeit the sticker on the rear wheel indicates 500w.

maybe it’s a 750w setup, I honestly cannot remember is they installed a 500w or 750w setup.
I’ll post the battery results when they’re done, but I can’t thank you enough for your assistance.

 

[Nealh]

What is the controller current rating ?

 

[Matt hignett]

What is the controller current rating ?

The controller box states:

max current 22a
rated current 11a

I’ve attached a couple of photos highlighting the box/label

 

[Nealh]

The motor wattage doesn't have an affect on the bike power output, it is the controller that matters. Yours indeed is 22a rated max, if you are seeing 700w in PAS1 then it must use speed control over current control.
If you have ever tried it does each assist level have a differing max speed set ?

 

[Matt hignett]

The motor wattage doesn't have an affect on the bike power output, it is the controller that matters. Yours indeed is 22a rated max, if you are seeing 700w in PAS1 then it must use speed control over current control.
If you have ever tried it does each assist level have a differing max speed set ?

To my knowledge there is no max speed set for each PAS, but I honestly haven‘t ever tried top speed in each PAS. I know PAS2 is quicker in both terms of acceleration and top speed compared to PAS1.

also, I have tested the battery at full charge immediately after 7nplugging from the charger. It was at 41.2v! After 2 hours (moments ago)! It tested at 41.1v. I’ll test again in two more hours.

 

[Nealh]

41.1v is a bit low is could be out of balance or on it's way out, lets see voltage wise what happens over night.

 

[Matt hignett]

Ok great, just checked again and holding steady at 41.1v. I’ll check again in the morning.

Thanks as ever

 

[Matt hignett]

41.1v is a bit low is could be out of balance or on it's way out, lets see voltage wise what happens over night.

Hi there,

I've just checked (so that’s 16 hours after first test) and the multimeter indicates 41.0v.

 

[Nealh]

41v is a good bit low for a 42v max charge, though 1v doesn't sound much in the bigger pics of things it is an indication of a failing battery if that is all it can manage.

It is possible cell groups are unbalanced and the only way of knowing is by opening the battery to check the 10 individual voltages, if this is the case one or two will show up being some what lower then the others. Alternatively one could try leaving it on balance charge for a whole day or even two but one should be aware of dangers that could exist so any such action should be undertaken away from the house and somewhere safer like an outdoor shed or under cover in a metal BBQ.

More likely dependent on the battery age is it needs recycling and a new one bought.

 

[Matt hignett]

41v is a good bit low for a 42v max charge, though 1v doesn't sound much in the bigger pics of things it is an indication of a failing battery if that is all it can manage.

It is possible cell groups are unbalanced and the only way of knowing is by opening the battery to check the 10 individual voltages, if this is the case one or two will show up being some what lower then the others. Alternatively one could try leaving it on balance charge for a whole day or even two but one should be aware of dangers that could exist so any such action should be undertaken away from the house and somewhere safer like an outdoor shed or under cover in a metal BBQ.

More likely dependent on the battery age is it needs recycling and a new one bought.

Thanks for the input. The battery label (see attached) indicates it’s a 36v 1300mAh battery.

is the likelihood the battery is at fault opposed to the controller then? Obviously the controller is relatively cheap to replace comparative to the battery albeit I’m happy to replace whatever is required.
thanks again for your sound advice, this forum and your good self are an amazing resource and one I’m glad to be a member of.

 

[Nealh]

No battery pic however it will be 13ah/13000mah.
The battery output charged voltage alone of 41v indicates all is not well and it has lost capacity, loss of capacity and voltage is caused by higher cell internal resistance coming to end of life.

Also the current rating of the controller at 22a and the fact you are seeing 700w in PAS 1 means the cells are under a lot of stress, the cells are likely the commonly used Samsung 2600mah cells with five in parallel to get the 13000mah rating.

I still think you have a speed control set up and a current control set up will be much better in use and for battery longevity/life.
The speed controller typically gives incremental max speed in each level often 2 or 3 mph and gives the same 700w or so of current in each level.
A current controller is the opposite max speed can be achieved in each PAS level varying the current in each level.

Because you have what I believe is speed control due to the 700w of power in PAS1 you will find a current controller very different, current control in PAS1 will only give provide about 150w gradually giving more current as you go up the PAS levels to max current in PAS5.

Temporary wire up your voltage meter or a simple £2 ebay voltage meter/readout to the battery/controller wires so that you can view the readout and go for a ride, take note of what happens to the voltage underload. The tell tale sign is the voltage collapses almost straight away and down to about 30 - 33v LVC.

 

[Matt hignett]

Photo of battery attached

 

[Matt hignett]

No battery pic however it will be 13ah/13000mah.
The battery output charged voltage alone of 41v indicates all is not well and it has lost capacity, loss of capacity and voltage is caused by higher cell internal resistance coming to end of life.

Also the current rating of the controller at 22a and the fact you are seeing 700w in PAS 1 means the cells are under a lot of stress, the cells are likely the commonly used Samsung 2600mah cells with five in parallel to get the 13000mah rating.

I still think you have a speed control set up and a current control set up will be much better in use and for battery longevity/life.
The speed controller typically gives incremental max speed in each level often 2 or 3 mph and gives the same 700w or so of current in each level.
A current controller is the opposite max speed can be achieved in each PAS level varying the current in each level.

Because you have what I believe is speed control due to the 700w of power in PAS1 you will find a current controller very different, current control in PAS1 will only give provide about 150w gradually giving more current as you go up the PAS levels to max current in PAS5.

Temporary wire up your voltage meter or a simple £2 ebay voltage meter/readout to the battery/controller wires so that you can view the readout and go for a ride, take note of what happens to the voltage underload. The tell tale sign is the voltage collapses almost straight away and down to about 30 - 33v LVC.

I semi understand/get the gist of what your saying and thank you once again. I will endeavour to get a readout whilst cycling and report back in due course.
with regards to the PAS vs w load in each PAS level. Is there a way I can reconfigure the controller in order to make best use of this? (In essence a current control setup?)

also, for speed to get back riding, would you recommend purchasing a battery post haste? I‘m still concerned that the battery operates sometime for 20 minutes before then having power loss but appreciate my knowledge is extremely limited.

I can’t thank you enough for this sound advice, your time (and patience) on the matter.

 

[Matt hignett]

Oh and if required, what controller would interface with my current setup in order to have a ‘current control setup’ opposed to a ‘speed control setup’. Please excuse my lack of technical terminology/understanding. I’m currently reading a lot of posts on the forum to try and seek knowledge as I’m keen to become knowledgable