My Bike Totally Died Today.

[Bobber]

I searched for this but couldn't find the answer here so apologies if it has been discussed. I converted my bike to the 1000 watt Bafang mid drive recently. I have the big 17.4 AH 52V whale shark battery. Everything was purchased as a complete system with less than 200 miles on the odo. I was doing my longest ride yet which was about 39 miles with some steep hills on paved roads, rough gravel roads and short downhill singletrack. My battery normally charges to about 58V and I always do a full charge. I have the recommended smart charger with the read out and my bike display also shows about the same volts. Everything went dead about 4 blocks from my house. The last voltage readout was around 42 volts and the display showed about half of the battery left. It also showed over 25 miles range left. Pressing the battery indicator button showed no lights. I have this incredibly steep hill coming up to the house and had to push the bike up it. Pedaling with that motor was a no go because it felt like I was pushing the motor also. Plugging the battery back into the charger showed the same 42 volts. I was able to get some indicator lights on the battery after a while as it got up to 50 volts. So I popped it back into the bike and everything works again. I have a few questions:

1. Is it normal for the bike to totally shut down like that? I kinda thought it would just have less power but still go.
2. What actually is causing the complete shutdown, battery, display, motor? Just wondering on this one.
3. I always pedal but I was hoping for some more range seeing as how I have the biggest battery they make. On the other hand it is frickin hilly around here. I took this one uphill (around 500' vert) that was over 10% grade and probably parts were close to 15% about 3 miles from the house. Maybe that just sucked the life force out of it. Does this range seem par for my setup?
4. Is it normal to feel the mid drive motor as a drag like that without any power? I haven't pedaled it without the power on since I installed the system so I can probably answer this tomorrow.
Thanks everybody. You guys are great.
Bobber

 

[RunForTheHills]

42V should be around the low voltage cutoff of a 52V battery. I would guess that is why it shut down. If you have a temperature sensor in your Bafang (BBSHD?), then the controller might have shut it down due to overheating to protect the motor. The BBSHD shouldn't overheat on a 10% grade if you choose the right gear and keep the motor RPM up.

 

[Explorer-1]

42V sounds right for a shut down on a 52V battery, that's 3V per cell and I have not seen one allow you to drop it for 2.5 for full capacity. I'm not sure what is shutting it down, but probably the logic in your display. I think the controller by itself would still try to run, but at 3V it's probably a good time to stop to not damage the battery (reduce the capacity). Depending on your setup the BMS itself might be shutting you down, if you would have tested the voltage on the battery right afterward without turning of the battery you could have detected this.

 

[Bobber]

Thanks guys. Yes it is the BBSHD. I felt the motor and battery right after shutdown and they were both barely lukewarm. It was a nice day, 78 degrees. So 42 volts is the limit I guess, now I can monitor it. Also now I know 39 miles is the limit on the more difficult stuff. I guess I'm complaining a little bit but I had dreams of going further. That really was a damn good ride. I feel kinda thrashed but in a good way. Drinking Makers now.

 

[RunForTheHills]

Many people buy a second battery for longer trips or bring a charger with them to bump charge at rest stops. The battery's range will decrease with age and also in cold weather.

 

[ExPatBrit]

There are specific instructions for 52 Volt and BBSHD,

52 volts is the mid-point, it probably charges to 57-58 volts.

If you have the USB programming cable (amazon) , you can check what cutoff the Bafang is set to. If you use a high level of PAS or throttle there is quite an instantaneous voltage drop under load which will trip the motor. I have my cutoff (48 volt battery) set to 40 volt but switch to eco mode when voltage is under 44.

 

[indianajo]

I use about 1/2 of a 17.5 AH 48 v battery on a 30 mile commute with ~80 hills. 53 v (85% charge) to 46 v. Were you lugging the motor in too low a gear? Is a bbshd that inefficient? I have a Mac12t geared hub motor, and lift 330 lb gross (80 lb cargo) up those hills.
I've warned 1000 people about mid-drives dragging the motor with your feet after the battery wears out. I've been told 2000 times how stupid I am to see this as a problem. I've ridden out & back 3 times without power after the rain took out the throttle, or most recently, burned a pin off the ASI controller. Carrying 16 lb of dead electric parts is nothing compared to dragging a motor with your feet. A 7 mph headwind is much more of a problem unpowered. If you have to have a mid-drive because you have a 1000' rise in your route, shimano steps, yamaha, and brose don't drag the motor with your feet unpowered.

 

[tomjasz]

battery indicato

An "indicator" is like a turn signal. You can still turn left with a right signal flashing. INDICATOR is not a reliable source of battery condition. Use your multimeter to give an actual voltage reading.

 

[Akrotiri]

I searched for this but couldn't find the answer here so apologies if it has been discussed. I converted my bike to the 1000 watt Bafang mid drive recently. I have the big 17.4 AH 52V whale shark battery. Everything was purchased as a complete system with less than 200 miles on the odo. I was doing my longest ride yet which was about 39 miles with some steep hills on paved roads, rough gravel roads and short downhill singletrack. My battery normally charges to about 58V and I always do a full charge. I have the recommended smart charger with the read out and my bike display also shows about the same volts. Everything went dead about 4 blocks from my house. The last voltage readout was around 42 volts and the display showed about half of the battery left. It also showed over 25 miles range left. Pressing the battery indicator button showed no lights. I have this incredibly steep hill coming up to the house and had to push the bike up it. Pedaling with that motor was a no go because it felt like I was pushing the motor also. Plugging the battery back into the charger showed the same 42 volts. I was able to get some indicator lights on the battery after a while as it got up to 50 volts. So I popped it back into the bike and everything works again. I have a few questions:

1. Is it normal for the bike to totally shut down like that? I kinda thought it would just have less power but still go.
2. What actually is causing the complete shutdown, battery, display, motor? Just wondering on this one.
3. I always pedal but I was hoping for some more range seeing as how I have the biggest battery they make. On the other hand it is frickin hilly around here. I took this one uphill (around 500' vert) that was over 10% grade and probably parts were close to 15% about 3 miles from the house. Maybe that just sucked the life force out of it. Does this range seem par for my setup?
4. Is it normal to feel the mid drive motor as a drag like that without any power? I haven't pedaled it without the power on since I installed the system so I can probably answer this tomorrow.
Thanks everybody. You guys are great.
Bobber

Bafangs quality control, durability and reliability is notoriously bad. The shortcomings you are experiencing is normal performance from bafang but not so from other more reputable manufacturers like Bosch,Shimano,Yamaha and brose.

How long ago did you make the purchase? Maybe you can send it back for refund if possible.

 

[ExPatBrit]

Bafangs quality control, durability and reliability is notoriously bad. The shortcomings you are experiencing is normal performance from bafang but not so from other more reputable manufacturers like Bosch,Shimano,Yamaha and brose.

How long ago did you make the purchase? Maybe you can send it back for refund if possible.

So should have bought and installed a high powered kit from those other manufacturers?

Do they even make them, do they market consumer self install kits?

If u read what the OP said, it does not sound like a Bafang motor problem, more likely a setup, BMS or battery issue.

Fortunately the OP has the option of doing some diagnosis , rather than dropping if off at the local electric bike shop.

 

[RunForTheHills]

So should have bought and installed a high powered kit from those other manufacturers?

Do they even make them, do they market consumer self install kits?

If u read what the OP said, it does not sound like a Bafang motor problem, more likely a setup, BMS or battery issue.

Fortunately the OP has the option of doing some diagnosis , rather than dropping if off at the local electric bike shop.

It is not actually a problem. He ran the battery down to the low voltage cutoff and the motor shut off. Once he charged it again, the battery was fine. He got 39 miles on a 905 WH battery (assuming the manufacturer claims are accurate). That is 23 WH / mile. While high, it is not outside the expected range with steep hills and depending how much pedaling he was doing.

 

[Akrotiri]

Do they even make them, do they market consumer self install kits?

If u read what the OP said, it does not sound like a Bafang motor problem, more likely a setup, BMS or battery issue.

Fortunately the OP has the option of doing some diagnosis , rather than dropping if off at the local electric bike shop.

Sounds like you didn’t read what the OP said.

He said his whole setup, motor, battery, controller and head unit are bafang.

I recommended that he should not have bought a bafang self-install kit and instead went with an e-bike that was either one of the big reliable four.

 

[ExPatBrit]

Do they even make them, do they market consumer self install kits?

Sounds like you didn’t read what the OP said.

He said his whole setup, motor, battery, controller and head unit are bafang.

I recommended that he should not have bought a bafang self-install kit and instead went with an e-bike that was either one of the big reliable four.

So spend $3-10k and then OP could then zip along at max 25 kph?

You get what u pay for, in this this case OP spent al whole lot less to upgrade a regular bike to go about twice as fast so some fettling is expected.
People make different choices in life. I fix my own cars and bikes, not everyone can. I have ridden about 5000 miles on Bafang powered bikes in the last 18 months. No problems.

 

[tomjasz]

Do they even make them, do they market consumer self install kits?

Sounds like you didn’t read what the OP said.

He said his whole setup, motor, battery, controller and head unit are bafang.

I recommended that he should not have bought a bafang self-install kit and instead went with an e-bike that was either one of the big reliable four.

 

[Bobber]

Thanks everyone for the great responses. I purchased the complete kit from Ebike Essentials which only deals in Bafang. I believe they are owned by Bafang. They stock the components in the US and Europe for people in those areas. They are very upfront about an item being in stock and ready to ship and I got mine in about 5 days. I purchased the best they had which was also the most expensive motor, battery, display etc for $1590 for converting a Specialized Crosstrail to an ebike. I've had that bike for 7 or 8 years now and it might be worth 400 as it was, so now I got $2000 into a pretty cool machine. It will do 36 mph on power alone.
Yesterday I was cruising around at the higher power levels plus 2 really steep hills and a few more smaller ones so I guess I just used the battery up I was not conserving at all. I did a 24 miler today with some intense backcountry and single track which was way harder than yesterday. But because I conserved I still had 50.9 volts when I got home and could make it up the last steep hill to my house which is 14 to 18% grade. I measured it btw. I think there is not that much motor drag after playing around pedaling on level ground with everything switched off. The issue yesterday was that I now only have a single 46 tooth sprocket in the front without the 2 lower gears that I had before and there was no way I could do that hill before the conversion without being in first gear and even then it was PIA.
This afternoon I get to clean the mud off my bike.
Bobber

 

[Rickman1]

Kudos to you for having the motivation to DIY. Sometimes you learn things the hard way, i.e., what your bike is capable of. I see a lot of people who think that THEIR ebike or choice of components are better than anyone else's. You like what you like and buy what you can afford. Therefore your ebike is the best...for you. Glad you're back riding and you figured out the problem.

 

[ExPatBrit]

Thanks everyone for the great responses. I purchased the complete kit from Ebike Essentials which only deals in Bafang. I believe they are owned by Bafang. They stock the components in the US and Europe for people in those areas. They are very upfront about an item being in stock and ready to ship and I got mine in about 5 days. I purchased the best they had which was also the most expensive motor, battery, display etc for $1590 for converting a Specialized Crosstrail to an ebike. I've had that bike for 7 or 8 years now and it might be worth 400 as it was, so now I got $2000 into a pretty cool machine. It will do 36 mph on power alone.
Yesterday I was cruising around at the higher power levels plus 2 really steep hills and a few more smaller ones so I guess I just used the battery up I was not conserving at all. I did a 24 miler today with some intense backcountry and single track which was way harder than yesterday. But because I conserved I still had 50.9 volts when I got home and could make it up the last steep hill to my house which is 14 to 18% grade. I measured it btw. I think there is not that much motor drag after playing around pedaling on level ground with everything switched off. The issue yesterday was that I now only have a single 46 tooth sprocket in the front without the 2 lower gears that I had before and there was no way I could do that hill before the conversion without being in first gear and even then it was PIA.
This afternoon I get to clean the mud off my bike.
Bobber

There is a learning curve, I switched from a "Bolton upgraded" Bafang geared hub to an Ultra with 17.5AH battery.

My first trips were somewhat under-whelming range wise but now I understand where the "sweet-spot" is I can conserve power and easily ride 50% further and make it up the steep hill to base.

 

[tomjasz]

. I believe they are owned by Bafang.

Bafang USA appears to be an arm of Bafang corporate. In fact they are just another reseller.

this letter from Bafang rep,


Bafang hereby declares that www.bafang-e.com is the one and only official website of BaFang Electric (SuZhou) Co.,Ltd.. Any other non-official websites with the word "bafang" in the url (e.g. www.bafange.com, www.bafangusadirect.com, etc.) has nothing to do with our company.

Bafang is not responsible for any problems resulting from any repair parts that are bought on these non-official websites instead of our Bafang official website, and does not provide any after-sales service. Bafang have already received complaints from customers saying that the goods they ordered from these non-official websites are not delivered after the payment, or wrong goods are delivered.

Bafang kindly reminds customers to be more vigilant. Feel free to forward this email to all your customers/dealers in order to reduce the probability of being deceived. If you have any questions, please find attached the statement for your reference.

Please also find the contact info below as the only official portal in the US for Bafang after-sales service. If you have any technical questions, please scan the WeChat QR code attached for a direct conversation with us. Bafang will reply you within 24 hours.

Johnny Qin / Techincal Support Executive
Bafang Science Inc.


Best regards,
Johnny Qin

 

[ExPatBrit]

Its a bit like those cell/mobile phone T mobile/ AT&T / Verizon kiosks in the mall. They are not official, just resellers.