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Deleted member 4366
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Some friends of mine bought a pair of these about 4 years ago. They're basically standard Schwinn bikes with Chinese electric kit added. They were very expensive when first released, but they didn't sell, so the price went down to about £800. They had one unique feature - a 24v 4Ah lithium titanate battery that lasts forever and can be charged in 10 minutes. So, with only 96Whs, it didn't go far and at only 24v it wasn't very powerful. That's probably why they didn't sell well.
Although the cells last forever, it seems that the rather exotic BMS draws power from them, so if you don't use the bike for a long time, the cells go below the minimum and the BMS shuts down. The cells are still OK, but the too intelligent BMS will not allow charging, even when they're manually brought to the correct voltage. The cells are 2.5v, so you can't change the BMS to a standard lithium one.
As both of these bikes hadn't been used for a long time, the batteries were shut down, so the owners asked me to fix them and, if possible, could they have a bit more more power and a throttle too?
Here's the stepthrough one:
The control panel is a standard 24v 4-wire one with a wire from the battery that's sent back down another to power the controller, a ground and a PAS level wire that goes 1v for level 1, 2v for level 2 and 3v for level 3.
My first thoughts were to gut the battery, re-cell it with normal Li-ion pack and solder the shunt in the controller for more current, but the controller is from Ananda and the components are potted in wax, so in the end I decided to swap everything for 36v. This is the controller:
So, new 36v rack battery, controller display, speed sensor and pedal sensor, plus the addition of a throttle. I made an adaptor lead for the motor connectors with a spliced-in speed sensor connector, as the controller's connector has the white wire for a motor speed signal, but this motor doesn't have a speed sensor in it, so I had to install a wheel-speed sensor. Before I spliced the speed sensor connector:
I had to rewire just about every connector, though all the wires are standard, so not too difficult. Here's the finished bike, now more powerful, a lot faster (unrestricted) and with about ten times the range, all for about £250. It's not a bad bike now with 8-speed hub gears, enclosed chain and comfy riding position. Why couldn't they have made it like that in the first place? They would have sold thousands of them - and made a profit!
Although the cells last forever, it seems that the rather exotic BMS draws power from them, so if you don't use the bike for a long time, the cells go below the minimum and the BMS shuts down. The cells are still OK, but the too intelligent BMS will not allow charging, even when they're manually brought to the correct voltage. The cells are 2.5v, so you can't change the BMS to a standard lithium one.
As both of these bikes hadn't been used for a long time, the batteries were shut down, so the owners asked me to fix them and, if possible, could they have a bit more more power and a throttle too?
Here's the stepthrough one:
The control panel is a standard 24v 4-wire one with a wire from the battery that's sent back down another to power the controller, a ground and a PAS level wire that goes 1v for level 1, 2v for level 2 and 3v for level 3.
My first thoughts were to gut the battery, re-cell it with normal Li-ion pack and solder the shunt in the controller for more current, but the controller is from Ananda and the components are potted in wax, so in the end I decided to swap everything for 36v. This is the controller:
So, new 36v rack battery, controller display, speed sensor and pedal sensor, plus the addition of a throttle. I made an adaptor lead for the motor connectors with a spliced-in speed sensor connector, as the controller's connector has the white wire for a motor speed signal, but this motor doesn't have a speed sensor in it, so I had to install a wheel-speed sensor. Before I spliced the speed sensor connector:
I had to rewire just about every connector, though all the wires are standard, so not too difficult. Here's the finished bike, now more powerful, a lot faster (unrestricted) and with about ten times the range, all for about £250. It's not a bad bike now with 8-speed hub gears, enclosed chain and comfy riding position. Why couldn't they have made it like that in the first place? They would have sold thousands of them - and made a profit!
