I'm currently designing my own e-moped for university (named ‘enduro 器’); I am currently going through the wiring and I am in need of some assistance.

the charging section of my wiring diagram (sorry if I am not using the correct symbols :D)

(refer to the image above) I want to be able to switch between the two onboard chargers with a 3-way switch. One is 5A, the other, 10A. Could you please advise the best way to do this? Ideally, I would hop off my bike, flip the switch to whatever charger I want (faster or slower) and then plug it in via a single/shared plug into the wall.


The 5A and 10A you mention are battery side, correct? ... it makes sense with the 50 Ah. Upstream on the AC mains the current will be lower, let's say no more than 5Arms.

Solution1. You can safely put a relay with rest position pointing to the 5A charger (lower=safer) and pushing a rocket switch (or a push button) you switch it to the 10A. You need coil voltage for the relay. It can come from the 48V always present at the output of the chargers when the input is plugged into the mains.

Solution2. You can put directly a switch able to handle the 5Arms or so. There are some, no problem. Or for more safety you can put a 2-way model, with the two contacts in parallel.


Note2: the switch is in the position upstream you have drawn; C&K has two contacts that can be put in parallel.

Question: what are those short pairs of marks on the left of the chargers? A symbol to say "two wires"?

  • \$\begingroup\$ This sounds like it will work. Could you possibly supply a simple diagram? It would be much appreciated. The left side is meant to represent a 3-way switch because I thought that would be a solution. I soon found that It's hard to find switches that can handle that power safely. Thanks :) \$\endgroup\$ – Owen Bramley May 28 at 5:16
  • \$\begingroup\$ @OwenBramley Done. Put a couple of devices from mouser, good stuff, from C&K and Carling. The diagram remains your diagram, so it is simpler. \$\endgroup\$ – andrea May 28 at 5:31
  • \$\begingroup\$ Thanks for your response @andrea, I was wondering how I would do this with a relay? Could I have a switch to control the mains (3 positions) and a relay to automatically switch each charger on the other end for the input to the battery? I was looking at 2 way relays, and maybe use the 120v to power the voltage coil to trigger the relay to the desired charger. LMK if this will work, cheers! \$\endgroup\$ – Owen Bramley May 29 at 2:48
  • \$\begingroup\$ @OwenBramley It is better to put the relay AC side , because 48 V with 5 to 10 A may stress its contacts significantly. You just select a relay with AC coil d you energize the coil depending o the position of the switch: 1 pos energized, other pos at rest (not energized). There is no third position, unless you use more than 1 relay and you set up a more complex logic function (cascading the relays). try a scheme where the switch is ow the relay, and the you switch on/off the coil with 120 VAC using a switch in series. \$\endgroup\$ – andrea May 29 at 7:05
  • \$\begingroup\$ @Andera thanks, I'll implement this into my circuit. Before I do, I want to confirm that the two chargers can be simultaneously connected to the battery i.e. charger1 (5A) & charger2 (10A) can both be connected to + & - to the battery at the same time essentially wiring them as a merge together as one cable going into the battery. \$\endgroup\$ – Owen Bramley May 29 at 7:18

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