Cyclotricity Stealth Owners thread.

[PH001]

The battery indicator on mine is the opposite to yours.....it can be nearly empty and it shows 4 bars, so i dont even bother with it now.

Just for clarification I am referring to the LCD indicator not the one on the battery. The two are almost completely opposite - the LCD often showing just one or two bars, the battery one pretty much always showing full even after the BMS has cut the power.

I do wonder if in fact this is affecting the range in quite a big way. If the battery one is the 'correct' one as cyclotricity suggest, perhaps the BMS is cutting the power way earlier than it should be because of measurement error? But then you would expect it to bounce right back up again when off load, which it does to some extent but not always enough to bring it back out of cutoff. I guess they build a fair bit of hysteresis in there to stop everything oscillating around the cutoff point.

 

[PH001]

You can use any battery. it doesn't have to be a Cyclotricity one.

d8veh - can you make any 48V recommendations?

 

[Andy Bluenoes]

Just for clarification I am referring to the LCD indicator not the one on the battery. The two are almost completely opposite - the LCD often showing just one or two bars, the battery one pretty much always showing full even after the BMS has cut the power.

I do wonder if in fact this is affecting the range in quite a big way. If the battery one is the 'correct' one as cyclotricity suggest, perhaps the BMS is cutting the power way earlier than it should be because of measurement error? But then you would expect it to bounce right back up again when off load, which it does to some extent but not always enough to bring it back out of cutoff. I guess they build a fair bit of hysteresis in there to stop everything oscillating around the cutoff point.

Right, sorry..I thought you meant battery.
The LCD on mine seems to realte to the load the battery is under, but again, its a bit of a chocolate teapot.

Battery appeared to be struggling at the end of my 15 mile run this morning, so pretty sure its not going to be good enough for 20 miles.

Ive emailed Cyclotricity this morning to see if I could also use the 48v 12 ah pannier rack on it....hopefully with an easy swap of leads when the first has drained....Only problem there is its another 350 on a bike that I may well end up replacing come June or July

 

[Deleted member 4366]

They're all a direct swap. What is it - 2 screws holding the receiver to the frame?

 

[Deleted member 4366]

When you take a big current from the battery, the voltage sags down. As the battery wears out, that gets worse.Range is reduced becayse the BMS shuts off the power when you reach the low voltage limit. You can often carry on a bit further by switching the battery back on and using a lower assist level, so less sag.

Which battery to get depends on how far you want to go and how you ride the bike. Key words in your search should be 30Q or GA cells. Alternatively, speak to Jimmy at BGA Reworking. His Boston cells look pretty good.

 

[PH001]

Good tips d8veh. There is also volt drop on any associated wiring from the battery to wherever the sense point is. I suspect the BMS senses battery volts in the FET block (but that's a guess) so the wiring from the battery to the FET block is important. I have to say it looks a little on the thin side on the Stealth for 1000W. I suspect the peak current is much higher than 20A.

 

[PH001]

The LCD on mine seems to realte to the load the battery is under, but again, its a bit of a chocolate teapot.

...that's because there is volt drop which shouldn't really be there. Cyclotricity labelling this as some kind of inverse 'load' indicator is a little creative to say the least!

 

[Andy Bluenoes]

They're all a direct swap. What is it - 2 screws holding the receiver to the frame?

I guess... but if i could get one with the same frame, I could still use both batteries

 

[PH001]

This looks very similar Andy... can't say for certain if they would be interchangeable on the same caddy though..

https://www.pandaebikes.com/shop/batteries/10-4ah-48v-dolphin-type-downtube-battery-lithium-ion-samsung-cells-uk-charger/

 

[Andy Bluenoes]

Cheers..it does look very similar...but its only 10 ah

 

[PH001]

Yep, I noticed that. I think the std is 12Ah although I've never measured 576Wh in practice.

Hmmph..going back to the volt drop issue, I think the BMS is actually in the battery so no external wiring will have any effect. Could still be thin wiring inside the battery I guess but that would take a battery strip down to confirm.

This article on building your own battery is a great read...
http://www.ebikeschool.com/how-to-build-a-diy-electric-bicycle-lithium-battery-from-18650-cells/

 

[PH001]

Maybe this (as a recommended supplier in the above article)?...

https://www.aliexpress.com/store/product/Free-shipping-Samsun-g-lithium-battery-48v-12ah-e-bikes-battery-with-charger/1804469_32266738171.html?spm=2114.12010608.0.0.7JggUx

Or the ultimate (expensive though)...
https://www.aliexpress.com/store/product/Super-Power-Elextric-Bike-Battery-48v-17-5ah-li-ion-battery-with-Sanyo-GA-18650-cells/1804469_32702184817.html?spm=2114.12010612.0.0.WkBKcE


..overseas of course

 

[Deleted member 4366]

If you go up to a 65 cell pack, which I'd recommend, it's advisable to put a third rivnut in your frame to support the extra weight.

 

[Andy Bluenoes]

Or the ultimate (expensive though)...
https://www.aliexpress.com/store/product/Super-Power-Elextric-Bike-Battery-48v-17-5ah-li-ion-battery-with-Sanyo-GA-18650-cells/1804469_32702184817.html?spm=2114.12010612.0.0.WkBKcE

Thanks again

I guess this would have to be the one....very pricey for what could be an interim measure....think ill jsut try and make the existing one last 20 miles until I can get the Oxygen

Cyclotricity have no update on 17ah and have not tested running two batteries and swapping out inline either

 

[Andy Bluenoes]

Well, on Friday, i had the chance to ride 20 miles, (6 miles then a break, then 14) similar route to what my new commute would be, and I managed to do it on one charge. No idea how much juice was left, but there was no apparent sag near the end.

Had to knock the assist down quite a bit, but averaged around 15mph without building up too much of a sweat.
So I guess I could stick with the stealth until I can get the oxygen.

I did find out since there were a few hills I dont often ride....the stealth is pants at getting up them.

 

[aardvark5]

I had the Stealth 250 watt front motor and then it was replaced for a 500 watt rear motor but I could get 2 miles from home and I'd be on a big bank where my 9aH battery just wasn't enough and the motor would keep kicking in and out. On a couple of days I found myself with no electric and trying to cycle up another bank with no assistance on a bike that felt like I was carrying another person on it. I decided to go back to the front 250 watt and I cycled a lot faster than I did on the bigger motor/heavier bike.

 

[OvercookedPeacock]

Hi,

Forgive me if this has already been asked/answered, but does anyone know the correct kind of freewheel removal tool I need to get the freewheel off of a 500W Stealth? The axle is way too thick for the two tools I have - they just won't fit on. Other forums seems to suggest the CyclePro CPT203, but the centre hole is too small. I have another generic one in my toolbox, but same problem.

The issue is a clanking sound - the wheel and hub motor have been back to Cyclotricty, who misdiagnosed the problem, changed the wheel and motor, but returned them with my original freewheel. Still got the sound, so the issue must be the freewheel.

Can anyone help?

Many thanks.

 

[Deleted member 4366]

DNP ones fit because they have the large I/D right through. If you get stuck, I have a few left over at £5 each inc postage.

http://www.ebay.com/itm/DNP-Epoch-Freewheel-Remover-fits-axles-up-to-14mm-/132135819283?hash=item1ec3e89813:g:kXQAAOSwB-1Y0vs2

 

[OvercookedPeacock]

DNP ones fit because they have the large I/D right through. If you get stuck, I have a few left over at £5 each inc postage.

http://www.ebay.com/itm/DNP-Epoch-Freewheel-Remover-fits-axles-up-to-14mm-/132135819283?hash=item1ec3e89813:g:kXQAAOSwB-1Y0vs2

Thanks for that. I have also found that Cyclo brand freewheel removers have a wide centre hole as well - bought one, and it did the job.

Incidentally, for anyone in a similar position, a Shimano MF-T721, 14-28, 7 speed freewheel is no good as a replacement for the Stealth's freewheel - it's too wide.

The Stealth uses a Nervar freewheel, which is now sold by BTWin, and can be found at Decathlon, here.

Hope that helps anyone in the same boat.

 

[Deleted member 4366]

You need a DNP freewheel that has 11T top gear. It'll make your ride miles better.