Sabvoton controller 72V and 12V power sources?

[xylene23nyc]

I am waiting on a Sabvoton 72100 controller and my goal is to power 12V lights and other accessories (direct from controller or dc-dc converter if needed) but wiring differs between vendors so am a bit confused with what I should/can tap into. I have searched/replied to other threads but have not gotten any response.

If possible I would like to avoid connecting dc converter directly to battery as I understand they can drain power outside of controller. Below is a photo of the wiring.


Could I tap into the 12v brake light cable for constant power to other 12V accessories and avoid using a DC converter? If so how much current can it safely supply? I have a 40W Moto light, Horn (1.5amps) and would like to power a few other small LEDS/accessories.

I maybe wrong but I believe there is also a 72V supply coming between the ignition and display lines? Could I tap into this for enough amperage to power a 12V DC-DC (15amp max) converter that then goes to the lights/accessories?

Any help is greatly appreciated.

 

[amberwolf]

Your controller probably has a keyswitch / ignition wire that has to be connected to battery positive to enable the controller.

if it does, then you simply connect the dc-dc's battery level input positive wire to the same side of the same switch you use to provide battery power to that controller keyswitch/ignition wire when you turn on the system. The controller won't supply the power, the battery will.


For 12v to run anything on the bike (besides stuff the controller needs to operate), you should use the dc-dc to provide that. don't use 12v from the controller to do it; they rarely have much to spare and you may either damage the internal 12v regulator or cause it to sag in voltage enough to cause unpredictable/undesirable operation of the controller.


also note that if your 12v stuff is standard automotive/motorcycle stuff, it actually runs off 13.6-15v, so you should get a dc-dc that outputs 13.6v-14v for the correct brightness, etc. if you only have 12v, lights may be noticeably dimmer than they should be, etc.


If you're going to use a horn, or any kind of incandescent or HID lighting, the DC-Dc has to be able to supply the full surge / turn-on current of those (whcih can be many times the "rated" current), or it may shutdown every time those are turned on, or even be damaged if it's not designed properly.

a "1.5A" horn could take, for example, 30a or more to get it started, just for a moment, then it drops down to the "rated" current while it's making sound.

 

[xylene23nyc]

Your controller probably has a keyswitch / ignition wire that has to be connected to battery positive to enable the controller.

if it does, then you simply connect the dc-dc's battery level input positive wire to the same side of the same switch you use to provide battery power to that controller keyswitch/ignition wire when you turn on the system. The controller won't supply the power, the battery will.


For 12v to run anything on the bike (besides stuff the controller needs to operate), you should use the dc-dc to provide that. don't use 12v from the controller to do it; they rarely have much to spare and you may either damage the internal 12v regulator or cause it to sag in voltage enough to cause unpredictable/undesirable operation of the controller.


also note that if your 12v stuff is standard automotive/motorcycle stuff, it actually runs off 13.6-15v, so you should get a dc-dc that outputs 13.6v-14v for the correct brightness, etc. if you only have 12v, lights may be noticeably dimmer than they should be, etc.


If you're going to use a horn, or any kind of incandescent or HID lighting, the DC-Dc has to be able to supply the full surge / turn-on current of those (whcih can be many times the "rated" current), or it may shutdown every time those are turned on, or even be damaged if it's not designed properly.

a "1.5A" horn could take, for example, 30a or more to get it started, just for a moment, then it drops down to the "rated" current while it's making sound.

Thank You!