new guy round here

[redbank]

Hello everyone,

Found this site when trying to research a solar unit for my small cabin. I currently have a goal zero package I bought 10+ years ago which runs about 5 lights at camp. I am looking to upgrade because my 10+ year old coleman instantaneous shower unit is basically dead. Going to start off with a 100w panel, 30 amp controller, 105ah agm battery to run about 6-10 12v led lights and a 12v pump for the new instantaneous hot water system for the shower. I have already purchased a fuse to place between the battery and controller, a 12v fuse block, 12v light receptacles with led bulbs and some 12/2 outdoor wire. I would like to have a main cutoff switch that can shut all my loads off when I leave but the battery and panel still working, if anyone can post any links for this I would appreciate it since my searching on here hasn't turned up much. The other question I am looking to answer is, do I run my load off the controller or directly from the battery? Thanks Don

[Mike90250]

Does your battery have both a post & wing nut terminal ? Then get a automotive battery cut off and clamp your loads to it, controller to wingnut

Run loads off the battery, most controller load terminals are only good for a very small load (just a couple LED)

[redbank]

Does your battery have both a post & wing nut terminal ? Then get a automotive battery cut off and clamp your loads to it, controller to wingnut

Run loads off the battery, most controller load terminals are only good for a very small load (just a couple LED)

It does.
My concern was running the battery too low and the controller is suppose to have an automatic shutoff when the battery gets low but wiring the load off the battery the controller feature won't work.

[SunEagle]

Hi redbank and welcome to Solar Panel Talk

Unless you have a high quality CC it is best to run your loads from the battery. Most of the cheaper CC have a "load" output that is rated very low in amps and a larger load will kill it.

Next I fear you do not have enough panel wattage to charge that 105Ah battery. You need about 10amps and a single 100watt panel will provide maybe half that.

There are a number of master cutoff switches that you can find on Google but you need to make sure they are rated to handle the voltage and amps for your loads.

[redbank]

Hi redbank and welcome to Solar Panel Talk

Unless you have a high quality CC it is best to run your loads from the battery. Most of the cheaper CC have a "load" output that is rated very low in amps and a larger load will kill it.

Next I fear you do not have enough panel wattage to charge that 105Ah battery. You need about 10amps and a single 100watt panel will provide maybe half that.

There are a number of master cutoff switches that you can find on Google but you need to make sure they are rated to handle the voltage and amps for your loads.

I do not have a high quality cc. The instructions/manual with it is very poor and lack of communications with them don't help either.

My cabin is only used on the weekends (and not every weekend) that allows it to charge during the week without any use, I don't have a problem purchasing another panel but I feel my amp draw from a normal weekend will be less than 50. I really don't have any knowledge on this and your help is appreciated.

[SunEagle]

I do not have a high quality cc. The instructions/manual with it is very poor and lack of communications with them don't help either.

My cabin is only used on the weekends (and not every weekend) that allows it to charge during the week without any use, I don't have a problem purchasing another panel but I feel my amp draw from a normal weekend will be less than 50. I really don't have any knowledge on this and your help is appreciated.

Well the better way of determining if you have enough battery is to find out the amount of watt hours you will use each day. That 105Ah 12v battery can safely provide you about 315 watt hours daily (105Ah x 12V x 25% = 315wh) without hurting it. If you use more you will reduce the life of the battery. On top of that if you don't provide 10% of the battery amp hour rating (or about 10.5 amps) for charging you will end up sulfating the plates and again kill off the battery sooner then expected.

Again since you do not use the system much it should get back up to 100% charge during the week but on the days you use it my fear is that you will drain the battery and will not be safely charging it.