12 V DC-DC Converter and Regen

[mexican_amigo]

Hello Endless Sphere,

I am wanting to power 12V lights from my 52V battery. I am thinking of hooking up a 12V DC DC converter in parallel with the motor. However, I use regen braking a lot and I am not sure how this would affect a converter. Does anyone know? My limited electrical knowledge leads me to think that most of the regen current would go to the converter because it is a bigger voltage drop than the battery (path of least resistance, right?) and that would fry the converter and/or lights?

On a side note, I am considering adding a second 52V battery and hooking it up in parallel with my existing one to essentially double my range. I have read other posts on this subject but there seems to be varying opinions. I would ideally leave them hooked up for both charge and discharge. I know that charging like that could be somewhat risky because one battery will be charged through the discharge port which bypasses the BMS, but what if you alternate which battery you charge from and only charge to 90% max. Does that help reduce the chance of errors?

I attached a quick circuit drawing of what I am thinking of making. I only took electrical fundamentals one in college so I apologize for the subpar drawing hehe

Thanks in advance!

 

[99t4]

There may be more simpler ways to power lighting from your 52V battery. For example, there are bicycle LED headlights that accept 9 - 84 VDC input. So you should be able to wire that into your 52V system, no converter needed.

 

[E-HP]

Just so I understand your sketch, currently you have your battery cables running directly to your motor, correct? (which would mean the controller is inside the motor).

I wouldn't keep the converter connected to the battery un-switched, unless you have a way to switch off your batteries. Otherwise, it would work.

 

[mexican_amigo]

My battery is connected to a phaserunner controller. My setup is 52V battery, phaserunner, cycle analyst and GMAC.

 

[E-HP]

My battery is connected to a phaserunner controller. My setup is 52V battery, phaserunner, cycle analyst and GMAC.

So where your sketch shows motor, it's the phaserunner. The converter will work, but you should make sure it can be switched off so it doesn't drain down your battery when you're not using your bike.