pianotuna wrote:
Hi,
It is NOT rocket science nor difficult to design an excellent system.
Here is a simple flow chart.
Budget-->Energy Audit-->Battery bank size-->number of watts-->PWM or MPPT.
What ever type of controller is chosen, make sure it has adjustable set points and a temperature probe that is on the battery.
One rule of thumb is between 60 and 150 watts of panels per 100 amp-hours of storage. The smaller the battery bank the higher the wattage needed (per 100 amp-hours). Here is a link to the rather special spreadsheet which includes an energy audit, that N8GS has created to help size solar battery charging systems!
Solar Spread Sheet N8GS
For a nice explanation of solar, try this link:
Golden rules of solar
Does my alternator underneath my front bonnet have a temperature sensor on the battery, despite me cycling it every day? I don't think so.
Unless you live full time off the grid, a temp sensor might be optional for you on your charge controller. If you get out quite a few times a year, and you top charge your batteries once the trip is completed, and as best you can during the trips, it's a non issue... the life of the battery won't be affected enough, nor the $ savings, unless you are RV'ing full time, or you have money to burn and you are a purist.
A temp sensor, for the weekend warrior, is fine, if you have more panel than you need. If you have just enough panel or are short a little bit on panel, to battery capacity, it's a non issue. I'd aim for 1 to 1.2 watts per amp of battery capacity, for solar panel, if portable, perhaps a little less, you will be sun chasing and they will give you a higher yield in amps for more hours per day, when aiming them at the sun, 3 or 4x a day. The OP is a truck camper... I am assuming he has a camper on the back of his truck. Think small, there's not a lot of power sucking devices on a camper shell.
