SOLVED! Best controller for a 8Fun (Bafang?) 250w 36v "SYXD01F" for my Faraday?

[Darthracing]

I am looking at swapping out the suspect electronics and battery on a dead Faraday I purchased.

Assuming the motor 8Fun is a Bafang and works, looking for parts - was hoping there was some consensus on standards or
parts to get/avoid...

 

[Darthracing]

Hey thanks - Faraday is/did run overvolted, battery is well over 36v

 

[Dewey]

I recommend you consider replacing the controller with a Grin Tech phaserunner, they sell a Z9 motor harness with 9-pin HiGo connector that ought to be compatible with a standard Bafang hub motor connector, but you should contact Grin to be sure. Get a Grin Tech Cycle Analyst display and a new external battery pack from them, possibly you will need to replace everything else including a PAS sensor and a throttle if desired, everything should plug and play.

 

[Darthracing]

Thanks I will check out “Grin”. Yes, I expect to swap out all the electronics. I was hoping to find an Arduino sitting there with jtag pins on the controller, just sealed boxes and proprietarty parts

 

[Dewey]

Yes, remove the frame battery there's no point carrying around dead weight, you may wish to keep the old Faraday controller box to keep the aesthetic. I agree with @Timpo this is an opportunity to consider upgrading the power by choosing a 48v battery. Grin Tech can tell you what to do, in the past the owner Justin has done a solid for Bionx owners with his video showing how to bypass the old controller and keep using the motor with the phaserunner controller.

 

[harryS]

There is no such thing as 36V battery for lithium ion.
The increment is 4.2V.

The 36V battery is actually 42V (@100%)

I don't know where they got 43.2V from. Even if you make it 11S instead of 10S, that would still be 46.2V.

It is a 12S battery. They only had room for a 12S-2P inside the frame tube, so they used as much as they could, 12 x 3.6 is 43.2V,

Twenty percent more WH than a 10S.

I'm sure the controller is still good. If it were my bike, I'd have a guy spot weld a new battery. It's 24 cells and they cost $9 each for Samsung GA 3.5AH and 10A peak. You can't get better than that, and anything else will look dorky, Well, maybe a round UPP battery would look passable, but it's only 10S and 20% less WH.

 

[Dewey]

anything else will look dorky

The OP might consider a brown leather frame bag. Depends on how they value color matching vs utility.

 

[Darthracing]

It is a 12S battery. They only had room for a 12S-2P inside the frame tube, so they used as much as they could, 12 x 3.6 is 43.2V,

Twenty percent more WH than a 10S.

I'm sure the controller is still good. If it were my bike, I'd have a guy spot weld a new battery. It's 24 cells and they cost $9 each for Samsung GA 3.5AH and 10A peak. You can't get better than that, and anything else will look dorky, Well, maybe a round UPP battery would look passable, but it's only 10S and 20% less WH.

Controllers are pretty stable then vs battery? What guys do batteries out there.

-T

 

[Dewey]

You have the Porteur model? The triangle is small so you should measure the dimensions to ensure an external battery case will fit. Do you have the front rack? That's another possible location, or a rear rack. Lots of battery vendors but you might want to see what Grin has to keep the connectors compatible unless you don't mind DIY. I have an EM3EV shark pack I bought via California Ebike, on the mounting foot I cut off the bullet connectors it came with and crimped on Anderson connectors.

 

[Darthracing]

It is a 12S battery. They only had room for a 12S-2P inside the frame tube, so they used as much as they could, 12 x 3.6 is 43.2V,

Twenty percent more WH than a 10S.

I'm sure the controller is still good. If it were my bike, I'd have a guy spot weld a new battery. It's 24 cells and they cost $9 each for Samsung GA 3.5AH and 10A peak. You can't get better than that, and anything else will look dorky, Well, maybe a round UPP battery would look passable, but it's only 10S and 20% less WH.

Should I crack open the battery case and check the individual cells? I am poking around with multimeter, get nothing except continuity between 1 pin of the
triple connector and one off the quad connector (I assume a ground)

 

[George S.]

The 12s is an easy type of battery to scrounge, just because there are a lot of 4s modules. If you buy 6 of these modules, you don't assemble anything and you put three in series and 2 in parallel. That gives you a new set of batteries, a brand name. All you have to do is wire them together, 3 in series and then parallel the 2 sets. Find a nice case. It's not big, not heavy. So it's $50 plus shipping.

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If this is 250 watts you need 6 amps, something like that, which is under 1C.

This is just a suggestion for someone who wants to go cheap and knows what they are doing. But it is 12s, name brand cells, new old stock. Easy to assemble. The welding is done.

Cheers and good luck!

 

[harryS]

In my opinion/experience, the cells in the video are too weak to build a 12S-2P battery. He's stretching the truth. The manufacturer says the cells will deliver 4100 mah, yet he's advertising then as potential 2900 mah cells. That 4100h mah is for a modem application. In the harsh world of motors, expect a lot less. In fact, when they're down to 50% voltge capacity, the voltage sag becomes overwhelming. I've seen cells like that shut off in my ebike when I blip the throttle.

How do I know? I've tried some of his salvage packs. They're OK to run my lights, speakers, etc. Disappointing for helping to run the bike.

There are many ways to repower that Faraday. I'd hate to put a Hailong wart on it. I'd go with a rack and leather panniers, with two small 12x2 21700 batteries in each side. shrinkwrapped, and padded.
About 2.5" wide, 5.5" long and 3" high. Each has a BMS and is stand alone. With 8AH in each side, each could run the bike at least 20 miles. Would cost me $200 per battery in parts alone.

 

[George S.]

In my opinion/experience, the cells in the video are too weak to build a 12S-2P battery. He's stretching the truth. The manufacturer says the cells will deliver 4100 mah, yet he's advertising then as potential 2900 mah cells. That 4100h mah is for a modem application. In the harsh world of motors, expect a lot less. In fact, when they're down to 50% voltge capacity, the voltage sag becomes overwhelming. I've seen cells like that shut off in my ebike when I blip the throttle.

How do I know? I've tried some of his salvage packs. They're OK to run my lights, speakers, etc. Disappointing for helping to run the bike.

There are many ways to repower that Faraday. I'd hate to put a Hailong wart on it. I'd go with a rack and leather panniers, with two small 12x2 21700 batteries in each side. shrinkwrapped, and padded.
About 2.5" wide, 5.5" long and 3" high. Each has a BMS and is stand alone. With 8AH in each side, each could run the bike at least 20 miles. Would cost me $200 per battery in parts alone.

WTF! You obviously didn't watch the video. He doesn't say they are modem batteries, he says exactly the opposite. He ran a test on the BMS and got 13 amps. So I'm saying use 2 sets of 3 (4x12 not 2), so 26 amps max so any normal 250 watt motor draw would be next to nothing. The information is contradictory. If they were 2900 mah cells, the two sets in the pack would not be 4100 mah, they would be 5800 mah or so. I can't find the cells, but it's a real company and the cells clearly are high power cells. Jehu has gotten sloppy, but most of the stuff is true. It's all salvage, all cheap, and when it works you save mega-bucks. I bought some very weak packs from the other guy, but he made an adjustment.

 

[Darthracing]

I left the stock battery on the charger overnight with a Kill-A-Watt to see how much was going into the charger.
A consistent 3 watt draw with all red-lights solid on the controller, 20ish Watt-Hrs burned.
No change to the performance with charger unplugged - everything still dead.

Assuming I won't electrocute myself on the dead battery, I am ready to crack open the case to see if I can swap out the cells inside.

I would like to keep the Faraday's sleek form factor, maybe use the electronics if the problem is all battery.

Observations:

• 1.645" / 41.8mm diameter with the calipers
  
• The ends are a different metal than the tube itself
• The tube ends are pinched/hammered with a pin to enhance traction on the end points (see pics)
  
• wired end
  • has a 2.5mm allen screw center, not very long (see photo below), not sure why or what is under it? white stuff? (see pics)
    
  • 2 additional ports covered with light rubber, moved them asside to reveal 2 holes. Multimeter here? Maybe batteries are in series 2x/end here? (see pics)
    
• non wired end
  • 1 blue rubber port on the other side - when pulled, more white stuff
    

Next steps?

• pipe cutter is too small to try spinning out the end-caps
• do I need to drill out the indented aluminum to free the caps?
• any dangers here to be aware of before I crack it?
• shop for replacement tubing - I could try debugging with a 12x1 18650 series setup in a PVC tube.

 

[Darthracing]

It is a 12S battery. They only had room for a 12S-2P inside the frame tube, so they used as much as they could, 12 x 3.6 is 43.2V,

Twenty percent more WH than a 10S.

I'm sure the controller is still good. If it were my bike, I'd have a guy spot weld a new battery. It's 24 cells and they cost $9 each for Samsung GA 3.5AH and 10A peak. You can't get better than that, and anything else will look dorky, Well, maybe a round UPP battery would look passable, but it's only 10S and 20% less WH.

Btw, I cracked open the battery - looks like 3 cells per row. Broke the BMS hidden in the far end. Picks below

 

[tomjasz]

I recommend you consider replacing the controller with a Grin Tech phaserunner,

I have a baserunner and a couple if their other controllers. The fact that I can run my 36V, 48V, and 52V batteries on the same controller makes them a win for me. As always others mileage may vary!

 

[harryS]

I think Jehi sells a lot of salvaged junk, GeorgeS. I still maintain that if you're hoping to use $1 cells for an ebike battery. you need a lot of them.

His salvage ebike packs are different though, Those were intended to run motors, and I admire how he has built little widgets to keep the proprietary BMS on some of those things working, And he has market prices on those Lishen 21700 cells too. You just have to be careful with that promo stuff.

 

[Darthracing]

Btw, I cracked open the battery - looks like 3 cells per row. Broke the BMS hidden in the far end. Picks below

Corrections - tube is about 20” long - about 8 x 65mm, so its still 24 cells! Crazy wiring likely required to get 12s2p in this 3x8 form factor.

 

[Darthracing]

Btw, I cracked open the battery - looks like 3 cells per row. Broke the BMS hidden in the far end. Picks below

And even more - peeled the aluminum pipe apart. A network of wires between the cells is in play to make the 24 cells into an 12s2p in this 3x8 pattern

 

[Darthracing]

I got my 48v water-bottle battery ($172 @ Amazon), drilled holes for the cage, soldiered up the power cable and it all lit up, motor started spinning with pedal action!