I wrote up this brief summary on my website and I'd love any input on making more accurate.
Programming The BBS02 Without Frying Your Controller And Losing Your Sanity
I’ve watched this thread on Endless-Sphere and spent a few hours building several of my own cables using different USB\Serial adapters bought on ebay and BBS02 extension display cables from EM3EV. If you want to remain sane and not waste a lot of your life beating your head against the wall I would recommend you just buy a cable for $25 from Matt at EMPowered Cycles. It is by far the cheapest programming cable have seen for sale, they are purchased direct from Bafang and they seem to work flawlessly with Windows 7/8/8.1. It is plug and play not ‘plug and pray’ like your cheap crappy homemade cables will be.
An important note, programming your controller will immediately void any warranty from Bafang. Don’t expect to make ANY changes to your programming and expect ANY dealer to refund or replace your blown controller, EVER. It’s just not fair to them.
Manufacturers of ebike motors walk a delicate line between making their drive motors configurable (even at risk to bad variables being entered) and completely locking down the system. Bosch has chosen to go the latter route and does not allow anyone other than Magura in the US to change anything on the units other than tiny changes like increasing or decreasing the wheel size slightly to account for different sized tires on the same sized rim. Bosch will never get a dime of my money.
There are 2 schools of thought on programming the BBS02. One school is represented by Paul (cellman) from em3ev who believes that you should make only minor changes to the software such as
Allow for 100% throttle at any PAS level
Allow throttle at PAS level 0 so you don’t have to disconnect the PAS entirely to use throttle only
Low voltage cutoff
Amps to the unit
Quotes from Paul about the much contested PAS system
“The PAS level should be used to set the pedal cadence. Just because it’s set to 9, does not mean it will pull more power (although it likely will of course), but if you pedal fast enough and hard enough to do much of the work, the kit will not provide much power. PAS works like a switch on the BBS02. It does not adjust as you pedal faster or slower. When you set the PAS level it fixes the speed and it does not want to rotate at a speed much lower than that, or even accelerate smoothly to that speed.”
The other school of thought held by many members of Endless-Sphere is that you should be able to change most any feature or variable you want to although we are literally wandering around in the dark since it’s not even clear what many of the variables even do. It is quite common for people to set the Limit Speed % on every PAS level to 100%. This seems to be a good way to destroy your controller and really drives Paul crazy. There is no programming manual and while Bafang does not prevent you from programming the unit, they certainly don’t seem to be encouraging it either. It seems clear that they never intended for the end users to be programming their own controllers, only ebike ‘dealers’.
Many people dislike the way the PAS system works, as the PAS level is basically a switch to set the pedal cadence and assists MORE the LESS you pedal and assists LESS the MORE you pedal. This seems to be counter intuitive to many who want the unit to offer more power the more you pedal. This means if you want the drive unit to provide more power on a hill you actually have to shift UP not DOWN to select a higher speed and a lower pedal cadence (or lower the PAS system to select a lower cadence as well as a lower power setting). This is not only counter intuitive, but also risks controller overheating as the biggest problem that I’ve found with the BBS02 is that they tend to overheat and fry mosfets when the pedaling cadence is too slow and the hill is too steep. The best way to keep your controller from overheating is to fit the right size chainwheel on it for the hills you plan to climb and consider upgrading the crappy mosfets the controller comes with.
I follow Paul’s school of thought, mostly because I buy from him and I trust his judgement. He has spent thousands of dollars replacing customers who reprogrammed their controllers, then fried them and expected free replacements. I just don’t karmically want to be one of those people.
To program the unit you’ll have to plug-in the USB cable (but don’t hook it up to the bike yet) and wait a few minutes. Then browse to the device manager in CONTROL PANEL->SYSTEM->DEVICE MANAGER and look for the com port under PORTS (COM & LPT) as shown below. If you can’t find it just flail around awhile, it will magically appear or maybe you’ll just end up destroying your computer.
View attachment 4
Once you figure out the com port you will need to download this file, then rename it to .zip and then extract it somewhere convenient. You’re looking for the file controllerst.exe . Make a shortcut to your desktop, that will make it easy to find when you need it. Load that program and then TYPE in the com port that you discovered in the device manager. For this example it would be COM4.
View attachment 3
Looks like a drop down box right? But it is not. You will have to type in your com port you discovered in the device manager.
The controller Info should fill in under the com port but the settings on the left won’t come up till you hit the READ button (not the READ FLASH button).
Now hook up the bike and the battery to the BBS02. Plug the USB wire into the green display port adapter, make sure your arrows line up, the connector is keyed.
Once you hit the READ button the setting for your controller should fill in the three different pages, BASIC \ PEDAL ASSIST \ THROTTLE HANDLE
There is a lot of different settings you can mess with as shown in the thread on ES about programming the controller. Here are the settings that my most recent BBS02 come from Paul pre-programmed with.
View attachment 2
I change the wheel diameter to 18 so that the km/h reads as mph, change anything other than the Low Battery Protect and Limited Current at your own risk.
View attachment 1
You can ignore the speed limited command here as in the previous page it is set by display’s command.
I have lots of hours on these controllers with no failures, so these are the settings I would use. The only settings I would change are the Low Battery Protect (v) which is useful if you are using a pack without BMS and limit current which will limit the current to the controller in Amps. You should match the limit current to the Continuous Amps rating on your BMS. Be aware that often times Chinese battery companies tend to exaggerate their continuous Amps ratings (except for Paul), so when in doubt, use a lower number and slowly work your way up. If you have a temp sensor in the controller (as shown here in step 12) you can get a pretty good idea about how hot it’s getting in there.
For anyone who cares here is a more technical description of the battle going on inside the controller by someone who is a lot smarter than I am on ES (probably better looking too).
Without phase current limiting there is no way to guarantee a motor will not overheat. You rely on the operator keeping the motor at a reasonably high rpm or minimising voltage applied to the motor at low motor speeds. The best a seller can do to avoid overheating is to keep the Limitspd% low so that little current is applied at low cadences but for an operator who avoids low cadence for more than a few seconds this is bad because the motor will provide no power at normal cycling cadences. An operator that keeps pedaling cadence in normal ranges, above about 60 rpm, with the BBS01 will never overheat the motor but an operator that lets motor speed drop below this risks overheating the motor with a wide range of controller settings. This would go away with phase current limiting but the BS0X doesn’t have that feature. The seller suffers potential warranty claims if the Limitspd% is set high but the operator suffers poor performance if the Limitspd% is set low. The current to the motor is also affected by “Keep Current(%)” and Current Decay (1-8)”.
Basically it means if you are climbing a hill you need to have a high cadence level if you want more power and your controller to not fry. I suggest using the thumb throttle on hills (not just the PAS) and shift into a low enough gear that is either too fast (or almost too fast) to keep up with pedaling. As long as the motor is spinning pretty fast the controller should never burn out regardless of how steep the hill is.
Here is another trick to bypass the speed limiting on the BBS02 from the thread on ES
For effective unlimited speed, change your wheel size to make mp/h show as km/h.
I.e. if you have a 26 inch wheel, set it as 16 inch wheel in the display (i.e. 26/1.61 = 16 – 1.61 is also roughly the same ratio as km to miles, as in 26km is 16miles). After making this change, then 25km/h on the display will in actual fact be 25mph in reality. No BBS unit is capable of 50mph, so it’s effectively now unlimited (or more accurately, speed limited by max current).
For most fatbike tires you would want to set the tire diameter to 18 (the 26″ tire is closer to 29″ because of all that extra rubber. 29/1.61 = 18)
Thanks to everyone who spent countless precious hours of their life trying to figure out how to do this and leaving behind a heart-breaking 32 page thread. Our knowledge is built on your blood, sweat, and tears … and your piles of dead controllers.
For some totally awesome pictures and actual links that I'm too lazy to add here go to https://electricfatbike.wordpress.com/2015/03/17/programming-the-bbs02-without-frying-your-controller-and-losing-your-sanity/
Ride On.
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