Bafang has finally decided that their P75NF75 mosfets on the 750 Watt BBS02 are grossly inadequate for the 1200 Watts that they allow to flow through the controller when it is cranked on. It sounds like they are now using the IRFB3077 mosfets which should run much cooler and be able to handle more amps for longer without popping like jiffypop over a bonfire.
What does this mean to you the consumer? It means you can beat on that new BBS02 even harder than you have been beating on your old BBS02 unit without fear of controller failure. That doesn’t mean that your windings won’t melt, the nylon gear won’t peanut butter and the axle won’t bend when you hit big drops, or your drive unit will fail in many other nasty ways. It does mean that the newer controllers should be less likely to fail.
Paul from em3ev just posted this on his website last week.
Since June we have been supplying all of our 750W BBS02 kits (controllers too) with an upgraded version of the standard controller. We have been supplying IRFB3077 mosfets to Bafang for fitment into our kits. Bafang almost immediately realised that what I’ve been telling them for over a year was true and they decided to use the same mosfets in future production (at least for the 750W BBS02, not sure about other models). Early signs are that this has improved the reliability of the 750W BBS02 Controller which has always been the weakest point of the 750W BBS02. Our version of the upgraded controller has a model number ending 206.1, whereas the previous version with lower specification mosfets had a number ending 206 (this numbering system applies to our kits, not sure how it applies to kits sourced elsewhere). To celebrate this improved product, we are making it easier to option the kit exactly as you want and with a little discount too
How do you know if your 750W BBS02 has the newer mosfets? If you bought it from em3ev and your model number ends in 206.1 or later than you are set. If you bought it from somewhere else then you might have the good mosfets or you might have the bad ones. It will be nearly impossible to tell without a whole lot of work. It does seem that any new BBS02 750W drive units ordered from this point forward from reputable vendors will have the newer mosfets. If your controller blows you can always just replace your mosfets yourself but be aware it is a royal PITA.
Lectric Cycles has also now started listing the BBS02 100mm drive units shipped with the newer mosfets as a different webpage from their normal 100mm kits listed here. The price is the same, $1200 for the 750W drive unit.
A huge thank you to Paul for advocating to Bafang on behalf of the disgruntled consumer and helping to produce an even better product to help compete with the grossly under-powered Bosch drive unit.
Did I mention how much I hate the Bosch drive unit?