1 Solar panel--2 Seperate batteries
I have a 100 watt solar panel. I want to use this 1 panel to charge 2 separate batteries in different locations. Will a wire splitter with 2 different control boxes work or should I get another pane...
Forum Discussion
Hi,
There are controllers specifically made for motorhomes with a primary and secondary twin outputs. What is does is charge the primary as much as it needs, and once it reaches 13.5 volts, it will charge the second battery until that one is full, then will try filling the first bank until it is at 13.8 volts, or the sun goes down.
If the first battery gets below 12.8 volts, even if the second one is not full, it will charge the first battery. This will work great, if you don't have space for a second panel. Yet as low cost as a 100 watt panel is, it might be best to get an additional panel and a low cost PWM solar controller. This might cost as little as $175 - $200.
SunElec.com is one place to find 12 volt nominal panels that will put out about 21 volts open circuit (when not under a load). This allows the use of a lower cost PWM controller.
I bought a 10 amp PWM solar controller for only $13 from AliExpress.com
I made panel mounts from 2" angle aluminum from Home Depot. Cut into 6" long with 3 holes 3/16" diameter and #10 screws into the roof and 5/16" holes for 1/4" bolts into the panel frames. Plenty of rubber roof sealant completed the installation.
I ran the wiring down the back of my refrigerator. using a coat hanger helps pull the wire all the way down. I was lucky enough to have a closet beside my refrigerator, and that is where I mounted the controller (with display) - the wiring inside the closet, the display on the hallway side of the closet wall.
Remember that a $200 solar system will last about 30 years. So that works out to about $15 a year, much less expensive than the battery it will protect for about 5 years (12 volts) or 10 - 13 years for golf cart batteries. So the solar system will outlast at least 6 12 volt batteries, or 3 or more sets of golf cart batteries.
Good luck with your project.
Fred.
There are controllers specifically made for motorhomes with a primary and secondary twin outputs. What is does is charge the primary as much as it needs, and once it reaches 13.5 volts, it will charge the second battery until that one is full, then will try filling the first bank until it is at 13.8 volts, or the sun goes down.
If the first battery gets below 12.8 volts, even if the second one is not full, it will charge the first battery. This will work great, if you don't have space for a second panel. Yet as low cost as a 100 watt panel is, it might be best to get an additional panel and a low cost PWM solar controller. This might cost as little as $175 - $200.
SunElec.com is one place to find 12 volt nominal panels that will put out about 21 volts open circuit (when not under a load). This allows the use of a lower cost PWM controller.
I bought a 10 amp PWM solar controller for only $13 from AliExpress.com
I made panel mounts from 2" angle aluminum from Home Depot. Cut into 6" long with 3 holes 3/16" diameter and #10 screws into the roof and 5/16" holes for 1/4" bolts into the panel frames. Plenty of rubber roof sealant completed the installation.
I ran the wiring down the back of my refrigerator. using a coat hanger helps pull the wire all the way down. I was lucky enough to have a closet beside my refrigerator, and that is where I mounted the controller (with display) - the wiring inside the closet, the display on the hallway side of the closet wall.
Remember that a $200 solar system will last about 30 years. So that works out to about $15 a year, much less expensive than the battery it will protect for about 5 years (12 volts) or 10 - 13 years for golf cart batteries. So the solar system will outlast at least 6 12 volt batteries, or 3 or more sets of golf cart batteries.
Good luck with your project.
Fred.
