harrisonpatm
Member
- Joined
- Jan 5, 2022
- Messages
- 401
Short question is in the title. Allow me to give details as to what I am looking for. I have ideas for building microgeneration systems, plural, and I am looking for individual components. In addition, I am looking to fully understand what every component of the system does, so I've got plenty of learning to do. I could go on Amazon and buy a charge controller, crappy wind turbine, and a car battery, but that won't help me understand what I am doing.
So here's my hypothetical situation. Let's say I have a small 3s battery pack using 18650's, BMS protected from undervoltage. 3s, so nominal voltage of 11.1V, topoff charge of 12.6V. I want to charge it with a small solar panel or wind turbine (rectified to DC). I could find an appropriate charge controller... but I keep seeing DC-DC CC/CV variable buck converters. They can take 3-30V input, regulate the output to a set level using a potentiometer, and as long as you select one that can handle the amps of your solar/wind, you could charge your bank. So I set the output to 12.6V to top off my 3S battery... but no, if there's any variation of the output of the buck converter, I risk overcharging the battery; even 12.65V could damage the bank. Ok, let's set the output to 12V even, gives me wiggle room for error. Some models I have looked at are the OSKJ, or the XL4016.
There are two questions I have with this setup, regarding what could go wrong, as my main concern is battery safety.
#1 What happens to the buck converter when the input of my wind/solar stops, at night or when there is no wind? I am concerned that the battery voltage will feed back into the buck converter and damage it, as well as unnecessarily drain the battery.
#2 What happens when the battery is fully charged and the wind/solar keeps producing? Are there some buck converter models that open the circuit after reaching the set voltage, to prevent overcharging? I don't want to have to rely on the BMS to prevent that. I know that some solar controllers just open the circuit, while most wind controllers divert to a dump load when the battery is full.
Why am I even exploring this route? My concept is small, numerous, cheap, and reproduceable power generation systems working in tandem. Either 10-20 small turbines, each with their own battery, or 10-20 of them each with their own buck converter feeding into and charging the same large battery bank. I know that MPPT or even PWM controllers do a better job or maximizing the power going into the batteries; I'm not concerned with that. I also know that the buck converter wouldn't be the only element needed in between the generator and the battery; rectifiers, fuses, extra wiring, ect, all add up, and in the end if may be the same cost or even more than just outright buying a charge controller.
My sole concern right now is battery damage and safety. Given that, and regarding my two questions above, how feasible is this method of charging a battery? Thanks in advance!
So here's my hypothetical situation. Let's say I have a small 3s battery pack using 18650's, BMS protected from undervoltage. 3s, so nominal voltage of 11.1V, topoff charge of 12.6V. I want to charge it with a small solar panel or wind turbine (rectified to DC). I could find an appropriate charge controller... but I keep seeing DC-DC CC/CV variable buck converters. They can take 3-30V input, regulate the output to a set level using a potentiometer, and as long as you select one that can handle the amps of your solar/wind, you could charge your bank. So I set the output to 12.6V to top off my 3S battery... but no, if there's any variation of the output of the buck converter, I risk overcharging the battery; even 12.65V could damage the bank. Ok, let's set the output to 12V even, gives me wiggle room for error. Some models I have looked at are the OSKJ, or the XL4016.
There are two questions I have with this setup, regarding what could go wrong, as my main concern is battery safety.
#1 What happens to the buck converter when the input of my wind/solar stops, at night or when there is no wind? I am concerned that the battery voltage will feed back into the buck converter and damage it, as well as unnecessarily drain the battery.
#2 What happens when the battery is fully charged and the wind/solar keeps producing? Are there some buck converter models that open the circuit after reaching the set voltage, to prevent overcharging? I don't want to have to rely on the BMS to prevent that. I know that some solar controllers just open the circuit, while most wind controllers divert to a dump load when the battery is full.
Why am I even exploring this route? My concept is small, numerous, cheap, and reproduceable power generation systems working in tandem. Either 10-20 small turbines, each with their own battery, or 10-20 of them each with their own buck converter feeding into and charging the same large battery bank. I know that MPPT or even PWM controllers do a better job or maximizing the power going into the batteries; I'm not concerned with that. I also know that the buck converter wouldn't be the only element needed in between the generator and the battery; rectifiers, fuses, extra wiring, ect, all add up, and in the end if may be the same cost or even more than just outright buying a charge controller.
My sole concern right now is battery damage and safety. Given that, and regarding my two questions above, how feasible is this method of charging a battery? Thanks in advance!