Will The Archon X1 Be Fine Tuned For Each Model ?

[Ebiker33]

This question is something for Watt Wagons to answer.
One bike has a cassette and a chain and a full suspension and is also lighter, the others a Rohloff and a gates belt, is heavier and are hardtails.
So do you program it slightly different in fine tuning to adjust it for the technical differences of the bikes ?

 

[pushkar]

Good question -
Short answer - not in this iteration of the firmware.

Long answer
1. Our first big priority / upgrade will be to support the upcoming transition of from UART to CAN (targeted by end of 2020).
2. As part of this late 2020 upgrade, we will try to provide some level of customization (torque and power per assist levels, similar to what the current firmware has today). This may need a custom display - we are working with a few vendors to get that done. Will probably be the same hardware as eggrider - but different firmware.
3. 2021 upgrades are focused on additional / deeper customization and also ride profiles (e.g. commuting, trail etc).

We need more feedback to evaluate what parameters need to be user configurable. I am working on a list of params we can expose, and will start a thread with those to see what can be realistically tuned.

 

[onlineaddy]

Thanks for continually seeking feedback from your customers, Pushkar.

 

[pushkar]

Here are some initial attributes a use can change (end of the year). Will keep adding to the list.
- motor max wattage (peak wattage, can tune down, not up)
- battery max. Amp.(eg 35E cells max out at 35A, HG2 can go up to 60A).
- motor max. Amp. (In case you don’t know cell config).
- adjust throttle power (eg cassettes may not need the limits imposed by IGH).

We will probably working on profiles - that appears to be the best way to manage the configs moving forward.

 

[onlineaddy]

Questions on the configurable attributes above:

• Aren’t the amp attributes gonna be determined by the cells you source for our battery packs?
• Throttle attribute will depend on whether we chose IGH or cassette for our bike; no?

For both what reason would the user need to be able to change the attribute values? In case we change batteries or drivetrain on our bike?

 

[pushkar]

Questions on the configurable attributes above:

• Aren’t the amp attributes gonna be determined by the cells you source for our battery packs?
• Throttle attribute will depend on whether we chose IGH or cassette for our bike; no?

For both what reason would the user need to be able to change the attribute values? In case we change batteries or drivetrain on our bike?

1. Yes - battery will determine max amps. Some users like to limit the amps to increase the longevity of the pack. e.g. if you only take the 1000W motor, you can limit the discharge to 30A just to be on the safer side.

2. Yes, throttle attribute will be pre-configured for the style of bikes we are selling. However users (can / should ) be able to change it if they switch from IGH to cassette. This will also be helpful for the motor kits we are selling (bring your own bike scenario)

 

[onlineaddy]

Right. So the benefit is mostly for motor buyers so that they can set these values themselves and not have to have you do it before shipping. These are mostly set-it-once-and-forget-it attributes even for them and particularly for full-bike buyers.

I look forward to configurable attributes that one may need to change more frequently due to conditions, moods, etc.

 

[pushkar]

Yup. Working on the ride profile concept. This way we have 3-4 profiles ready to go and you can switch quickly.

 

[onlineaddy]

Yup. Working on the ride profile concept. This way we have 3-4 profiles ready to go and you can switch quickly.

Fantastic. Will these profiles be user configurable? Or, are the settings for each profile fixed from the factory/you?

 

[Ebiker33]

Yup. Working on the ride profile concept. This way we have 3-4 profiles ready to go and you can switch quickly.

Is that like a car; eco ride, cruise ride, turbo ride, turbo sport max ride(100% on everything) ?
Or are they 1 per bike that maximizes the the ability of each Ebike configuration which will be slightly different ?

 

[onlineaddy]

Pushkar says 3 to 4 profiles from which you can switch.

 

[byunbee]

- motor max wattage (peak wattage, can tune down, not up)

Just to clarify, if you bought the highest powered motor version, you CAN adjust the wattage up and down correct? I hope you're not saying once you adjust it down, you can't go back up.

 

[Ebiker33]

@pushkar

What is the controller amps rated at for this system, It must be a different amp rating for each style of wattage or is something else is controlling that.
The high end bikes that pull 1600W are 35Amps, but with 52V you could get away with 30amps.
I haven't seen the posted rating anywhere for this.

Revision Edit:
I did find this with your batteries, is that correct ?

1. 750W nominal (25A continuous)
2. 1000W nominal (30A continuous)
3. 2300W Nominal / 3000W peak (45A continuous /55 A Peak)

 

[pushkar]

Fully unlocked controller upper bound can be set to around 57A (52*57 =~3000W).
The BMS will almost always be lower (you can see the ratings from EM3ev's as a reference)
- Samsung 35E will be ~25A continuous and ~35A burst / peak.
- LG HG2 will be 45A continuous and 55A burst / peak.

You are right that 52V can get away with lower continuous amps than the 48V to support the same "power". The secondary advantage of using 52V system is that you can get by with lower C rated cells (like Samsung 35E) for most uses. This will not work for the higher wattage motor. A 48V system will not be able to support the 2300/3000W peak system.

 

[Bluzrif]

For the un/ less initiated... is it possible or practical to specify generalized use cases for each wattage setup? Or is it a case of more Wattage and bigger battery is always better and let you wallet be your guide?

 

[pushkar]

I will approach this from the motor perspective and try to keep it somewhat simplistic (also because selfishly my understanding is limited and i dont want anyone to find out )

1. Extreme example - 3000W peak motor.
current Bafang and Archon supported batteries are 48V or 52V. So to get to 3000W
- 48 V battery will need 3000/48 = 62.5 A discharge current (bookmark this number - we will address this later)
- 52 V batter will need 3000/52 = 57A discharge current.


2. Lower bound example 750W motor.
- 48 V battery will need 750/48 = 16A A discharge current
- 52 V batter will need 750/52 = 14.5A discharge current.


This tell us that all things remaining the same, to support a motor with X wattage, a 52Volt pack will need lower discharge current than a 48V battery pack.

But wait - It doesn't matter what the battery can discharge at, the BMS (battery management system) is the actual gatekeeper of the battery health. Most BMSes only support limited discharge currents (25A continous, 35Peak), regardless of what underlying battery you use, to protect battery health etc etc..

Watt Wagons BMS supports 40-45A continuous with a burst/ peak of 60A. (notice the 60A number?) . Larger capacity BMS also typically means larger size plus need for better thermal management since higher current is flowing through the wires.


Limitation of the 48V pack - notice that to support 3000W we need the 48V pak to discharge at 62.5A... but the most any current ebike BMS can do is 60A! So we end up in a scenario that with the current state of BMS it is not possible to support a 3000W motor with a 48V battery pack. Current BMS tech is pretty good.. and going beyond 60A burst is not needed for 99.999% cases.

Addendum - So how do we support higher (say 4000W peak) systems ? Well.. we use a higher voltage battery like 72V or even 96v !
so 4000W/72 = 55A, and 4000 / 96 = 41A... both of which can be managed by the BMS.
Addendum 2 - Bafang and Archon X1 only support 48 / 52V... so we are at a hard limit of ~3000W peak with current tech.

There is clealy more nuance to this whole this, and battery / BMS junkies will murder a philistine like me for advertising a 50.8 volt system as 52V etc etc.. but you get the overall idea.


TL;DR It is not just the size of the battery - it is the base voltage, the BMS capacity, and the types of cells needed to support the motor wattage you need. More money will get you a battery system that can do 750W to 3000W with ease. Also Star Wars > Star trek.

 

[onlineaddy]

Of course Star Wars > Star Trek

 

[onlineaddy]

So for 3000W peak we need the 52V battery and BMS to burst/discharge 57A. But, I thought you said even the LG HG2 can do only 55A. What batteries will you use to reach 57A?

 

[Ebiker33]

Also if you are draining only 14.5 Amps your run time is going to go up verses the 60A which will drain the battery very quick, unless the new controller is smart in that it has 60A available to pull from, but if you are in PAS 1 going on flat terrain it can draw less to extend it's run time ? Taking only what it needs when it needs it, for example a 250 lb man peddling up a 15% grade hill in PAS 5, verses a 133lb woman peddling on the flats in pas 1.

 

[pushkar]

So for 3000W peak we need the 52V battery and BMS to burst/discharge 57A. But, I thought you said even the LG HG2 can do only 55A. What batteries will you use to reach 57A?

both 30Q and HG2 do up to 60A. The 55A is for disclaimer purposes.

That being said, the BMS itself does have a hard cut off at 60A.