ElectricMotorcycleForum.com

I want to think before I fry my controller and am asking for comments from experienced gurus here.

I have 4P4S setup of 20Ah 12V AGM batteries and ME-0708 motor (DC, brushed).

Getting my bike to speed is bloody slow now (will change gearings, now 11:41) but still; the idea of passing the controller does not give me rest.

Would I fry the controller and why, if I had a switch which had dual relay (plus, minus) bypassing the controller for acceleration? Relays would connect battery pack minus and plus to controllers motor-contacts directly. Controller would remain connected, but the juice would flow directly from batteries to motor. When I would release the switch, the relays would open and then all the juice would go once again through the controller.

I guess coming back from bypass would be the challenging part.

Referring to http://electricmotorcycleforum.com/boards/index.php?topic=476.0 my Cagiva el Freccia:

I have ME0708 & Sevcon Millipak 4Q and 4 series of batteries hardwired in parallel.

Wires are decent quality 16mm2 copper with decent quality coppery ends, pressed with pro tools. Within a serie, there is 'only one' such wire, where all the energy is involved, I have doubled the wiring, so there is 32mm2 for juice to flow.

Q1: 16mm2 & 32mm2 ... is it good enough? The wires from controller to motor seem to get warm. Single 16mm2 got not warm but hot. Comments? What kind of wires you others use for brush type DC motors?

Q2: I  have set up the controller to give 300A (that is, full 100%) when needed. However, I have never seen more than 225A in ammeter (is it a real word?) Any clues?

Q3: when starting from dead zero, I see only 50A or so in the ammeter. I do know there are safety mechanisms in the controller but I have set them to minimum (I think). Should I get 300A from the dead zero? If not, why not? The acceleration is not as good I'd like to have. Before I got the setup up and running, I imagined that I could just turn the throttle and let the motor have the forementioned 300A...

Q4: AGM batteries; I do know that you should not let the batteries to 'empty'. In real life, how bad is it to 'crawl' home with the batteries bottoming out just to let them be recharged immediately? Here I would appreciate a comment from a real AGM expert

Q5: I have a 48V 'truck' charger that has charging profile suitable for AGM batteries. There are several options for charging voltage. I suppose it is safe, fine and OK to have "55V" to charge parallel series of 12V batteries?  That divided by four gives less than 14V per battery. I understand you could give even 15V without killing the battery, but is there something special to consider, when having 4 series or 4 batteries here?

Q6: I take 12V for the lights and such from one 'random' battery. I do know that this is 'wrong way to do it' but just how bad is it? I have LED rear lights, LED winkers and run only with parking lights (which I will replace with LEDs any day now). Actual driving lights are only for the police, if they want to stop me for checking out the bike. I have original light bulbs in place

Q7: Ammeter tells that there's a small current (0.09A) running through the system, when powered off. Should I be worried?

Q8: Based on your experiences, is my motor getting enough air to cool itself? Are there specific warning signs to notice before the motor melts?

Q9: Should I be worried of something that I have not thought of?

Q10: Is bypassing the controller a bad idea? I think about having "full speed" setting, where controller would not be used to restrict the juice flow. (button, relay giving all there is in the batteries directly to motor)

Q11: If and when motor overheats, the solderings (?) inside the motor melt, right? Is it possible to fix, or is the motor wasted when this happens? How about having a "thermal fuse" inside the motor? Something that would 'safely' melt, when there is too hot? (Like they have a lead bolt in the steam engine water tank wall. Or something like that.)