An "old" thread here
Battery Extender Continuing with the experiences and learning of the Orbea Gain D50, I have come to the conclusion that it will not be bad to have a battery extension system. We have optimized the administration of the energy available in the main battery to the maximum, we have gotten...
www.pedelecs.co.uk
The range extender works differently to other additional batteries, like say the Bosch double battery system. It works like a powerbank charger for your phone. It gives a fixed 2A charge through the main battery's charge port all the time you're riding. If you ride using an average of more than 2 amps, which is 50w help at the wheel, it won't keep up, so you wouldn't get all the charge out of it unless you stop for a long time to let it catch up. It's a very weird way to do it.
It should be possible to use any extender battery by wiring it to the Mahle battery's main power output wires with blocking diodes in series. That would probably only work if the Mahle battery sends the signal that it's OK. The X35's controller is inside the battery unit, so that would probably involve difficult surgery. If they've combined the BMS and controller, it would probably be impossible.
The speed derestrictor device uses the principle I proposed. It interrupts and spoofs the speed signal. You can make your own for the cost of the two connectors. It appears to have a standard 9-pin Julet connector, but the motor has the PAS activated by the freehub. I've never seen one to figure out how that works. If the sensor is external, all good, but if its internal, it would need either an extra wire in the harness to carry its signal or a comms unit in the motor to send the data along with the speed signal, and the speed derestrictor must translate the speed signal.
Until someone opens up one of these systems, we can only theorise. AFAICS, it's pretty well locked, so avoid unless you don't mind keeping it as it is and paying for repairs. There are motors from Bafang and AKM that do the job just as well that can use any controller and battery for a fraction of the price.
