Controller differences: S12P vs S12S

pn_day

Pedelecer
Jul 26, 2013
185
40
St Andrews, Fife
Hi all,
I've had an order with BMS battery for a while; I finally found out that the delay was due to S12S controllers being out of stock. I've therefore asked them to send on the rest of the order including the S12P.

Apart from the power output being different between the 2 controllers (easily fixed by soldering the shunt), I'm assuming it is still worth changing over to the sine wave (S12S) when they are back in stock as it drives the engine more smoothly thus potentially making the engine quieter?

I'm hoping that I can get everything wired up and test it with the S12P then swap for the S12S. Does that sound like it should work?
Thanks
Phil
 

eHomer

Esteemed Pedelecer
Aug 20, 2012
635
164
Hi all,
I've had an order with BMS battery for a while; I finally found out that the delay was due to S12S controllers being out of stock. I've therefore asked them to send on the rest of the order including the S12P.

Apart from the power output being different between the 2 controllers (easily fixed by soldering the shunt), I'm assuming it is still worth changing over to the sine wave (S12S) when they are back in stock as it drives the engine more smoothly thus potentially making the engine quieter?

I'm hoping that I can get everything wired up and test it with the S12P then swap for the S12S. Does that sound like it should work?
Thanks
Phil
I must have been lucky then Phil , just before BMS ran out of S12S controllers. I ordered a few bits and pieces from BMS about a month ago and it all arrived in 7 days, including an S12S and an S06S.

I'm pretty sure that your plan to switch controllers will be no problem, other than slightly different sizes maybe. The plugs and sockets should be identical, and the PAS and throttle are the same. The control panel may be different though. I'm not sure if the BMS sine wave and square wave controllers have different panels.

As for the efficiency and smoothness of sine wave, I took advice from this forum last year and converted a previously purchased simple ebay 250w kit from square to sine wave with a new BMS LCD panel and S06S. It was on a DIY conversion of my Alubike, and the transformation was well worth the trouble. It was indeed quieter, and smoother, with less "electric milkfloat" whine on take-off ! The five level PAS was much more flexible too.

That's why I then more recently upgraded the excellent MXUS cassette motor that I bought from d8veh. I fitted the S12S and upgraded the battery from 36v to 48v. The transformation is remarkable. The significant extra power is admittedly due mostly to the voltage increase, but once again, the noise level has dropped and the smoothness has increased.

As the proportion of shipping costs drops so significantly when buying multiple items from China, I bought another S06S and panel at the same time, which I'm currently fitting to my Hase Lepus recumbent trike (in my Avatar).

I fitted a Q100 328rpm 20" front wheel motor to an old Dahon folder earlier this year, which was also a very successful conversion, running on 36 volts, giving a max of about 18 mph.

I hit on the idea of having the flexibility of using the Q100 20" wheel in either the Dahon or the Lepus by wiring both up with controllers and throttles etc., and just quickly switching the wheel between them, using the single waterproof 8 way plug and socket.

Since the motor and the battery are the only items of any significant weight, it's very quick and easy to just switch the front wheels to have either ebike or pushbike, with no downsides.
 
D

Deleted member 4366

Guest
They're interchangeable. It would be interesting to see what the real difference is back-to-back. When I met them at the show, they showed me the new programmable displays, so I asked if they could get me a S12S and SO6S and two displays to take back. They brought them the next day and they only wanted about £60 for all four items. Some guys get all the luck. My turn this time. The S12S didn't have a label, so might have come from different stock, although what would they put on the label if it's programmable?