Donniesuits
New Member
- Joined
- Aug 19, 2020
- Messages
- 18
Hello All!!
Question about the amps rating on boost / buck converter and my amps requirements for lighting.
I have a small 12 volt DC solar system, LiFePO4 batteries with Victron MPPT controller. I want to use the load out on the Victron MPPT to power some 12 volt DC lighting and connect it to WiFi light switches and my Alexa setup. The WiFi switches are 12 volt DC Shelly 1. I contacted Shelly 1 support as the manual stated that the WiFi switches need to be 12 volt DC regulated to get the definition of regulated. They stated that the switches are 12 volt DC + or - .5 volts max and if connected straight to a LifePO4 battery I will burn out the switches. The 13.5 volts to 14.5 volts while charging will definitely burn out the connected Shelly WiFi switches. I then contacted Victron to see if the load out on the MPPT controller was regulated and Victron support told me the load out is not regulated and it will just pass the battery voltage thru so a battery charged to 13.5 volts will put 13.5 volts to the load out terminal on the controller.
The solution is a buck / boost device connected to the load out on the Victron MPPT controller and then to the Shelly WiFi switches which will keep the voltage at a constant 12 volts DC.
I next go to an online watts to amp calculator so that I buy the correct buck / boost device and find myself questioning the math and my thinking, so here is where I get stuck and was looking for some help. I have (5) 12 volt DC lights and the bulbs are 20 watt bulbs for 100 total watts. When I enter the numbers (12 volts DC and 100 watts) into the watts to amps calculator I get 8.33 amps. The Buck / Boost DC - DC 12 volt converters that I found come in 5, 10 and 20 amp sizes. Well 5 amp is too small, 10 amp does not leave any room for addition power connections in the future and I am about to go with a 20 amp buck / boost. I guess my concern is does 5 little tinny lights really require 10 amps, 10 amps sound like a lot compared to these 5 tinny puck lights or am I not calculating my needs correctly.
Thanks for the replies and the confidence that I have done the math correctly.
Question about the amps rating on boost / buck converter and my amps requirements for lighting.
I have a small 12 volt DC solar system, LiFePO4 batteries with Victron MPPT controller. I want to use the load out on the Victron MPPT to power some 12 volt DC lighting and connect it to WiFi light switches and my Alexa setup. The WiFi switches are 12 volt DC Shelly 1. I contacted Shelly 1 support as the manual stated that the WiFi switches need to be 12 volt DC regulated to get the definition of regulated. They stated that the switches are 12 volt DC + or - .5 volts max and if connected straight to a LifePO4 battery I will burn out the switches. The 13.5 volts to 14.5 volts while charging will definitely burn out the connected Shelly WiFi switches. I then contacted Victron to see if the load out on the MPPT controller was regulated and Victron support told me the load out is not regulated and it will just pass the battery voltage thru so a battery charged to 13.5 volts will put 13.5 volts to the load out terminal on the controller.
The solution is a buck / boost device connected to the load out on the Victron MPPT controller and then to the Shelly WiFi switches which will keep the voltage at a constant 12 volts DC.
I next go to an online watts to amp calculator so that I buy the correct buck / boost device and find myself questioning the math and my thinking, so here is where I get stuck and was looking for some help. I have (5) 12 volt DC lights and the bulbs are 20 watt bulbs for 100 total watts. When I enter the numbers (12 volts DC and 100 watts) into the watts to amps calculator I get 8.33 amps. The Buck / Boost DC - DC 12 volt converters that I found come in 5, 10 and 20 amp sizes. Well 5 amp is too small, 10 amp does not leave any room for addition power connections in the future and I am about to go with a 20 amp buck / boost. I guess my concern is does 5 little tinny lights really require 10 amps, 10 amps sound like a lot compared to these 5 tinny puck lights or am I not calculating my needs correctly.
Thanks for the replies and the confidence that I have done the math correctly.
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