Power cuts out as soon as load increases

[Nealh]

Standard KT Sm (non waterproof ) connectors then.
Yes the 9 fet are 22/25a but you can reduce the current, controller are a bit larger.

 

[Parsons]

I'm sure they do pswpower controllers on AliExpress

 

[Nealh]

6 fet KT.

Page Not Found - Aliexpress.com

 

[Chris Maluszynski]

I'm going to revive this thread, as I just made some new observations.

Apparently, if I switch "gear" (power level on the LCD) from the maximum (5) which I used before, to 4 or 3, the behaviour of the controller is different.

Using the throttle, there is no difference: I can still get it to run if I increase super carefully, and it still cuts out if I push a little too far.

But using only PAS, power does NOT cut out. Even on steep hills, when the load is definitely very high. I should add, at 4 it still occasionally cuts out, but at 3 it doesn't at all. If I use a combination of PAS and throttle it cuts out again (even at 3).

Does this narrow down the problem somehow?

Thanks again

Chris

 

[Parsons]

You have a simular problem to me no power cut out but use 1to 5 on pedal assist works fine but throttle 1 to 2 OK but start of with number 3 or higher will lock the wheel up abitl with a grinding noise

 

[Nealh]

Chris the issue is still down to the battery not being able to supply the current asked of it and sags terribly when current is asked of it.
Early in the thread you mentioned the battery was stored and not use for a couple of years, although LG cells you haven't said which ones but my guess are the MG1 2850 mah cells, LG have some great cells but this isn't one of them, it is at best a low power cell.

 

[Chris Maluszynski]

Chris the issue is still down to the battery not being able to supply the current asked of it and sags terribly when current is asked of it.
Early in the thread you mentioned the battery was stored and not use for a couple of years, although LG cells you haven't said which ones but my guess are the MG1 2850 mah cells, LG have some great cells but this isn't one of them, it is at best a low power cell.

Hi Nealh
I thought we excluded the battery as voltage does not drop when power cuts out?
Also it’s apparent it can supply the current as it runs on full power up steep hills as long as as only PAS is used.

 

[Nealh]

Hi Nealh
I thought we excluded the battery as voltage does not drop when power cuts out?
Also it’s apparent it can supply the current as it runs on full power up steep hills as long as as only PAS is used.

You said PAS 3 it doesn't cut out which is about 33% current/ power, PAS 4 it occasionally cuts out which is 50% current/power. You only get the full whack of 100% current/power via PAS 5 or throttle. The battery in the upper PAS levels of 4 or 5 & throttle cannot handle the 8.5a or full 17a load asked of it.

The load under power is either the cells can't handle the current asked of it or there is a bottle neck due to the wiring not being able to carry the current. For 17a current flow you need 16 awg wiring or better.

 

[Chris Maluszynski]

You said PAS 3 it doesn't cut out which is about 33% current/ power, PAS 4 it occasionally cuts out which is 50% current/power. You only get the full whack of 100% current/power via PAS 5 or throttle. The battery in the upper PAS levels of 4 or 5 & throttle cannot handle the 8.5a or full 17a load asked of it.

The load under power is either the cells can't handle the current asked of it or there is a bottle neck due to the wiring not being able to carry the current. For 17a current flow you need 16 awg wiring or better.

Thanks Nealh for explanations.
I must have misunderstood earlier as I was about to order a replacement controller (There was mention of FETs failing as a potential cause of the problem.)

It seems to me like the bike is pulling at its max capacity (or near it) up hills even though it’s only on PAS 3.Maybe it has to do with the motor being a standard 250w bafang, and it can't pull all of the 17a?

The theory of failed cells seems likely but would they fail just like that after functioning perfectly for six months of usage?

Same with the bottleneck/wiring. Nothing has changed (unless some wires have become damaged suddenly). So would it occur suddenly from one day to another?

Should I then not order the replacement controller then?

And is it worth looking for the damaged cells? Or how do I proceed?

thanks again and sorry for being such a noob