Yosepower 350w 48v keeps cutting out - maybe related to throttle.

Hello

 

Had the above kit for a couple of years now and been pretty reliable. This morning however on riding it I found that it was cutting out. I jangled the cables around a bit and it would usually come back to life but it does appear to be getting worse (this happened a couple of times in the last few days). Interestingly it appears to be ok again until I try and use the throttle when it then cuts out but shows on the display that I am using the throttle!

 

I recently disconnected everything to change the PAS and the bag holding the controller so it might be that things are a bit loose. I am going to try and spray each connection with contact cleaner (unless I shouldn't?) but other than that I am not sure what to do. Any experience of similar from you folks?

If the display goes off then it's a battery contact issue, if the screen stays on then the cells are aging and the cutting out is bad/severe voltage collapse. The latter is a sign of the cells past their best, if the battery is some 50/60% depleted or more then the likely hood of LVC coming in to play will be greater.

Using the throttle demands max current draw from the battery, cells age and lose there ability to supply the current asked for, the voltgae collapses to the LVC then when power demand is reduced is quickly recovers to a higher level.

 

To be sure of the above wire up a voltage meter of any kind to the battery/controller feed wires and then apply the throttle, watch the voltage and see what it does.

If the display goes off then it's a battery contact issue, if the screen stays on then the cells are aging and the cutting out is bad/severe voltage collapse. The latter is a sign of the cells past their best, if the battery is some 50/60% depleted or more then the likely hood of LVC coming in to play will be greater.

Using the throttle demands max current draw from the battery, cells age and lose there ability to supply the current asked for, the voltgae collapses to the LVC then when power demand is reduced is quickly recovers to a higher level.

 

To be sure of the above wire up a voltage meter of any kind to the battery/controller feed wires and then apply the throttle, watch the voltage and see what it does.

 

Thanks Neal that is a really useful answer. I actually hadn't considered that the battery would be a factor. I bought it in September 2019 and have used it quite frequently but would probably say realistically I've charged it maybe 50 times. I have also kept it inside and made sure it is charged regularly. It was sold as a Samsung celled battery and so I am surprised it would already be showing signs of aging but then it does sound like that is the case.

 

I don't have a voltage meter but will get my hands on one (what self respecting E biker doesn't have one!) and check that out. What am I looking for when I do this?

Though Sam cells are used like a lot of branded and non branded ones they all make different varying amperage cells, because of the pricing structure the cells will be lesser amperage ones of approx. 5.2a rating. Over time even a short space of 18months use they will suffer loss of capacity more voltage sag, I can't be 100% sure that this is your issue but is most likely so.

How often is high PAS or throttle used as this will degrade the battery cells much sooner then using a lame PAS 1 as I do for longevity and range.

Although some ebike batteries may use the same type of cell a car uses and think that is good, it has to be remembered that a bike battery only have 4 or 5 cells in a parallel string where as a car will have approx. 30 or 40 cells or even more in parallel and approx. 100 of these cell groups for a 400v battery.

Though Sam cells are used like a lot of branded and non branded ones they all make different varying amperage cells, because of the pricing structure the cells will be lesser amperage ones of approx. 5.2a rating. Over time even a short space of 18months use they will suffer loss of capacity more voltage sag, I can't be 100% sure that this is your issue but is most likely so.

How often is high PAS or throttle used as this will degrade the battery cells much sooner then using a lame PAS 1 as I do for longevity and range.

 

Oh no I think you could be right. I am very lazy and use the throttle a lot on max power. I had no idea this would wear the batteries down and so did it thinking nothing of it! Adding weight to your hypothesis, I used the bike this morning with a freshly charged battery and had no issues at all! I am assuming that on full charge the loss of capacity isn't as noticeable as when it is lower in juice. I think I have noticed a correlation and certainly it had only some charge when I last used it and had significant problems.

 

I guess nothing lasts forever but I was hoping it might last a little longer. I suppose it is still functional at least and works well when charged.

When it cuts out under throttle one will have stop using the throttle and opt to use PAS1 or 2 to reduce the current load/voltage sag.

My Sam 29e's acted like yours but were a lot worse, my 14.5ah battery would do about 20 miles in PAS2 and about 40in PAS1, If I used throttle I barley got many miles. They were about six years old though.