Short distance folding ebike to put in the boot of my EV

[Jon Matthews]

Can you weigh yourself twice for each?

With and without holding the battery and deduct for the difference.

With and without holding the bike and ditto.
.

I'll call in at the vets on Monday and use theirs, they won't mind as I spend a small fortune there.

 

[guerney]

I hung mine from a ceiling hook and digital luggage scale. I don't think my measurement was accurate - I got different readings each time, depending on how well the bike balanced.

 

[Jon Matthews]

I have a couple of those scales but not tried that yet. My Engwe C20 Pro has a few problems, one that didn't surprise me and two that did. So the one that doesn't surprise me is the wheel bearings were too tight, easy fix. The next problem was when I'd fully charged the battery overnight and off the bike, the display showed two bars out of five, like the battery wasn't charged. I checked the battery off load and the charger off load and both read 41 volts, this doesn't really give you the SOC but it's indicative. So I thought my best course of action would be to factory reset the bike. That made no difference at all, so that was one surprise. The second surprise was when I deflated both tyres to add sealant. I inflated the rear first on the bike with my small electric pump, which can deliver high pressure but low volume. The innertube pushed the tyre bead off the rim at about 15 PSI and made a massive bulge. I have never seen that before, its like the tyres too big for the rim. I did the same on the front off the bike and exactly the same happened. I deflated them both and put 5 PSI in them with my pit pump and checked the tyre rim bead was seated properly. I then got brave and managed to get them both up to 20 PSI. The tyres are 20" x 3" and some Chinese brand I've never heard of.

 

[guerney]

The next problem was when I'd fully charged the battery overnight

I avoid charging any lithium battery unattended, unawake!

 

[Jon Matthews]

I avoid charging any lithium battery unattended, unawake!

It's in my garage.

 

[guerney]

The second surprise was when I deflated both tyres to add sealant. I inflated the rear first on the bike with my small electric pump, which can deliver high pressure but low volume. The innertube pushed the tyre bead off the rim at about 15 PSI and made a massive bulge. I have never seen that before, its like the tyres too big for the rim. I did the same on the front off the bike and exactly the same happened. I deflated them both and put 5 PSI in them with my pit pump and checked the tyre rim bead was seated properly. I then got brave and managed to get them both up to 20 PSI. The tyres are 20" x 3" and some Chinese brand I've never heard of.

 

[Jon Matthews]

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That's very interesting, do you have a conclusion based on the limited info I've posted? I'll have another look at the tyres tomorrow as I'm just taking my dog for a walk at the moment. Thank you.

 

[guerney]

That's very interesting, do you have a conclusion based on the limited info I've posted? I'll have another look at the tyres tomorrow as I'm just taking my dog for a walk at the moment. Thank you.

I have never seen that before, its like the tyres too big for the rim.

You may be right about the tyres being too wide for the rims - measure the rims? Even 15psi could be too much for some fat tyres?

The next problem was when I'd fully charged the battery overnight and off the bike, the display showed two bars out of five, like the battery wasn't charged

I'd demand a refund ASAP, if the battery looked in any way suspect. One of our resident battery experts may advise.

 

[guerney]

The next problem was when I'd fully charged the battery overnight and off the bike, the display showed two bars out of five, like the battery wasn't charged

do you have a conclusion based on the limited info I've posted?

I think you may have a duff battery.

 

[Nealh]

Check the battery voltage with a meter, it wil soon tell you if there is an issue.

 

[Jon Matthews]

Have a read further back in the thread Neal. The battery was measured at 41 volts off load after charging.

 

[StuartsProjects]

I checked the battery off load and the charger off load and both read 41 volts, this doesn't really give you the SOC but it's indicative

A voltage of 41 volts suggests the battery is (close to) fully charged.

What you dont know is its capacity in Ahr.

 

[guerney]

I checked the battery off load and the charger off load and both read 41 volts,

3,086 km ago, my battery charged higher than it's currently charged 41.5V - why is your charger only providing 41V?

I used to get 43 zero effort miles from my 19.2Ah battery at 100% "Keep current" (it's a firmware setting on the bbs01b) at 15A.

 

[Nealh]

41v is a bit low for the charger, unless they use a custom BMS that balance at less then 41v.

 

[Jon Matthews]

Mysteriously after playing with the settings today and riding about 4 miles the display ended up showing all 5 battery bars, no idea how that happened. In the back of my mind I seem to remember someone saying on a YouTube video that the battery indicator didn't read properly until you had a few miles on the clock. I did 9 miles today and it took one bar off the battery. I also found out the tyre's are lethal when it's damp

I'm also struggling with wheel diameter selection (Ld). I should be able to select between 8 to 26 inches, 700C, or 28 to 30 inches. I seem to have a scale from 50 to 1000 inches so I've set mine to 200 inches which makes no sense.

 

[AntonyC]

Some cycle computers want circumference so you could try around 65". Given 41V from your charger it's worth comparing your voltmeter with another, a few of my cheapies vary that much from the calibrated one.

 

[Jon Matthews]

Thank you very much Antony, that makes sense. I have now got another problem as I have an error 3 code which I can't reset. I'm going to have to deal with the supplier, hopefully they will assist, watch this space.

 

[cyclebuddy]

I'm also struggling with wheel diameter selection (Ld). I should be able to select between 8 to 26 inches, 700C, or 28 to 30 inches. I seem to have a scale from 50 to 1000 inches so I've set mine to 200 inches which makes no sense.

Fiido use Yolin displays on their bikes too, some appearing to be modified to Fiido's own spec.

On my own Fiido wth Yolin display, the convention is 160 = 16" wheel, 200 = 20" wheel, 260 = 26" wheel and so on. So it's 20.0 inches, not 200 inches.

I think that's not a bad way of doing it: If you change tyres to a taller or lesser profile (as I did) you can tweak the setting in 0.1 increments to make your speed/ODO/trip more accurate (eg: compared to GPS), so you may for example use 198 (19.8) for a 20" wheel with a larger/taller tyre, or maybe 201/2/3 for a low profile tyre.

 

[Jon Matthews]

Fiido use Yolin displays on their bikes too, some appearing to be modified to Fiido's own spec.

On my own Fiido wth Yolin display, the convention is 160 = 16" wheel, 200 = 20" wheel, 260 = 26" wheel and so on. So it's 20.0 inches, not 200 inches.

I think that's not a bad way of doing it: If you change tyres to a taller or lesser profile (as I did) you can tweak the setting in 0.1 increments to make your speed/ODO/trip more accurate (eg: compared to GPS), so you may for example use 198 (19.8) for a 20" wheel with a larger/taller tyre, or maybe 201/2/3 for a low profile tyre.

Interesting but irrelevant now for me as it's going back to the supplier.

 

[cyclebuddy]

I'm not altogether surprised. On paper it seems a good deal, but looked at closely it just seemed to me to be too good to be true. I like a bargain as much as the next man, but superficially there's just too much on offer for the £1000 being asked - there'd have to be compromises somewhere if not everywhere.