Building an EV more efficient than walking

[Colin Deng]

In China the Ebike can only run at 25kmh
But i am thinking to bypass the limited of my Ebike, which can make my bike run at 40kmh

[Saladin]

Look's like my motor is somewhere in the ether in Asia. If I wanted it sooner it would have cost another €100..

The battery arrived. We'll get back to that. First let's address the setting your house on fire or not scenario.
Yes that's an issue. It's not what you think.
As usual the battery gets blamed for issues with the charger.

My triangle battery was recalled. I declined the opportunity to "discard it with extreme prejudice and demand a refund". I have opened it, the cells look genuine. It meets specification. There's no internal temperature management...except atmospheric I suppose. It's no better or worse than the rest that didn't get recalled by most of the industry because they were in a diferent shaped enclosure.


If it's UL listed it's a higher standard.



Guns don't kill people bullets do..or was that people?..or systemic misconduct?...moving on...



Most e-bike batteries come with a "charger" included in the price. These are nothing more than pretty rough constant voltage power supplies. If you want a real charger pony up for it.

If you use the charger that comes with the battery and you leave it on the absolute max acceptable voltage that the cells can handle for days on end then what do you expect to happen?

Here's a few mods to help. I generally don't charge a battery with these unless I'm nearby to turn it off when the battery is charged. Probably advisable to use a plug -in timer with it if you want the belt and braces..what¿ wait!..no! buy the satiator for that!...if you want to be extra cautious use a plug-in timer.

The first thing I do is a fan transplant. The stock one is very irritating.



Next have a look at the output.



4.2V x 14cells series = too bleedin' high with no bejaysusin' overhead..



and I'd rather 2000 cycles to 85% SOC rather than 500 to 100%




Derate!!!!!!!!

See that potentiometer that says VR1 for voltage regulator 1?



Twiddle it until it outputs 4.1V per cell.



Presto that batteries "lost" 15% usable but it'll last 4 times longer and it's waaay less likely to burn your house down.

And no don't trust it anyways. Attended appliance!

I've killed a 400VA Victron Phoenix with one of those..noisey b%gg*rs..big Studers don't like them either but they're able to handle 'em.

[Saladin]

While I'm on the subject of leckytronics...

...How do I limit discharge of the ebike battery when I'm plugging it into an MPPT charger?

Step one:
Make one of these.



Step two:
Gerra Morningstar ProStar Gen III with a display.

Step Three:



Done!
Questions?

[Saladin]

Brakes with integrated Motor Cutouts

Mehyeah...ok they're a thing...
I fit them on other peoples bikes.



I like the option to brake under motor power for traction through corners. Yes it burns the pads and rotors like Billio, I'm my own mechanic. Does knowing better make it ok?
If you pull the brake you load the tyres giving you traction...don't overdo it....that has the opposite effect. While powered, you can corner faster with this technique. I'd advise 4 pot callipers with heatsinks, Sinted pads and big rotors if planning on making a habit of it.

The standard kit comes with two options. Replacement levers with integrated switches for cable actuated brakes and reed switches which are magnetically actuated switches you're supposed to glue to the lever and pair them with a magnet on thuther side of the hinge.
It's a fancy momentary switch.

Option three is splash out on hydraulic brakes with integrated levers...careful not to downgrade the second most important system though. I usually trust the stock brakes more than the entry level ebike brakes.

I harvest the Higo connector and put a push bottom on the cockpit. I also use it as an electronic clutch to avoid crunching gears shifting under load.



Whenever I cycle a muscle bike I automatically reach for the button every time I change gear. A bit like stomping on the floor of a car with my left foot when I'm diving an automatic because I'm so used to manuals.

I also fit automatic gear sensors ...I'll get to that later...

[Saladin]

Cockpit underway.

Kits come with thumb throttles. I prefer the half twist. Thumb throttles can be chilling on the digit in Winter and they surge like a ****er when you're getting bounced around off-road because it's impossible to hold them still when the handlebars are jumping.


Mirror placement:

Slow bike = Under bar.
Fast bike = Over bar.

You're trying to avoid looking at your elbow.

[Saladin]

In China the Ebike can only run at 25kmh
But i am thinking to bypass the limited of my Ebike, which can make my bike run at 40kmh

Hi Colin.
I thought it was much higher in China.
My LFP battery supplier said something like 60kmph and I thought

Best of luck with implementing your decision.
25kmph is pretty slow alright. Stay safe!

[Colin Deng]

In China the Ebike can only run at 25kmh
But i am thinking to bypass the limited of my Ebike, which can make my bike run at 40kmh

Hi Colin.
I thought it was much higher in China.
My LFP battery supplier said something like 60kmph and I thought

Best of luck with implementing your decision.
25kmph is pretty slow alright. Stay safe!

The Ebike is not allowed to overspeed than 25kmh, this is the law in China
But after we get the license of the Ebike, someone will try to bypass the speed limited

It will be safe

[Saladin]

It varies in difficulty Colin. It very much depends on the bike. Some you can fool by changing your wheel diameter {EDIT: ...On the controller settings}. This will also make the speedometer inaccurate. If it's a mid-drive you might be able to put a bigger smaller driven wheel on it {EDIT: fooling the speed sensor but also reducing your actual top speed achievable}. Some controllers you only have to disconnect a wire. Others like Bosch want ~€150 for a black box interface and void your warranty on the entire bike.

Some bikes just won't have the power to go faster anyway because small motors are already geared to max RPM at 25kmph. Derestricting something like that certainly makes the power output smoother but doesn't equate to much higher speeds.

I like the Bafang BBS kits you can put them on most bikes, they're budget friendly and fully programmable.
I hear good things about C.Y.C. too. The Bafangs are relatively open source, fully serviceable, pretty straight-forward and fit most normal bikes compatible with off-the-shelf batteries. That sortov engineering gets my vote every time.

[Saladin]

There's generally two schools of thought on system reliability. You can make it bulletproof at great expense or good enough and have a spare. I find the latter far more reliable and relaxing when things do break, given you retain a reduced operational capacity and donor parts if the failure is unrecoverable.

Hence a second hard-tail..



What's with the old 26"ers? (~2010 Vintage)
It's the era when standards were standard! I can swap bikes or parts. Modern bikes for all the frills are a nightmare for compatibilty.

The spare hardtail is my eMTB functional rolling parts department. Also a lender for visitors. She's been built from leftover parts after upgrading or rotating parts from my daily. They've swapped forks at the moment, brakes, wheel, the lot below the handlebars. It might be a while before they get swapped back if ever.
Batteries are interchangeable.

My fleet have all the same wheel size, tyre setup, drivetrains (albeit with a few non-funtional sprockets on the hand-me-downs) same brake disc rotor diameter same pads etc...bar the Roady Onlys (700C wheels built for efficiency and max range ) . The tyres get downcycled as part-worns according to who's in need with priority going to the torquey-est.

The conversion kits are mostly the same some BBS02s and some BBSHDs.

My school of engineering is; build it, send it, break it, rebuild it stronger, repeat until it don't break. I stopped getting upset about things meeting an untimely end a long time ago. I run a tough proving ground. Only mustard cutters survive.

[Saladin]

Fresh boots arrived!



I stopped getting punctures every journey after I swapped to Schwalbe. Addix compound, the tough, hard-wearing, heavy carcass bottom of the range.
Good enough with motor assist!



I run a gnarly 2.35" Magic Mary on the rear of my hardtails and a lower rolling resistance 2.15" Smart Sam up front. Having a wider rear makes the bike lurch into corners. You'd want to go the other way for Enduro; a wider front has more responsive handling. I heart the Magic Marys as a rear, not too many places I can't get. Some I couldn't walk.

I thought I'd try the Smart Sam as a rear on the Cargo....I know some day eventually I'll be wanting to take her off the tarmac.



Clears the mud guards (...welll...part-worn ones do..)



But not the chain stays.
I'll haveta get me nob trimmer out and do a job on those side nobs if I want that one to work...doable...maybe later...

Back to plan A: Wider Road tyre.
Increased air volume really does have a significant increase in suspension.

If you want the tyre to seat round on the bead it's best to lubricate it. What?! Yes I did say you should grease your tyres! Look you can't believe everything you read on the internet!!!



Some people use water. I use silicone grease. Wipe off the excess after yer done it'll be grand! I've never had much success with water.



You could park a bus in there...it's like I'm not trying...