valhalla360 wrote:
StirCrazy wrote:
DiskDoctr wrote:
I tried out that solar calculator.
It came back with 530 watts with 55 amp MPPT, 425ah lead acid batteries.
Used winter numbers with furnace at 20hrs per day, 0.5hrs microwave usage, etc
We have 4x 6v golf cart batteries (Duracell) and 2kw inverter. Batteries are a few years old, always connected to 4 stage charger/AC. Believe they are 215ah/each with 2 pairs in parallel (standard for 12v setup)
Likely will be adding a 24/7 camera and internet wifi backhaul link across the top and then down the mountainside to our house. So that will add a little more usage.
so if thats what you are getting , I would personaly pad my chances and at least double the solar panels and batteries. if I got that for numbers I would put 3 or 4 400 watt panels and I would double your battery capacity to help keep the usage under 50% of the battery capacity to get maximum life. and theres no harm in haveing extra battery capacity for thoes stormy few days when you won't get full preformace from the solar.
The website already has depth of discharge as part of the calculations.
Padding a bit is a good idea but I would be looking at 10-25%, not double. Better to look up the wifi & camera specs and put in real numbers. The idea of doing an audit is not to just pick random numbers out of your.... At 24/7, the wife/camera could be fairly substantial.
A big question if camping in the dead of winter (as evidenced by 20hr of furnace run time), is what sun-hours did you select. Normally, using 4 is a good generic assumption but most people don't camp in the north in the dead of winter.
I did a quick check and in Erie PA for a panel mounted flat, it varies from 1.13 (December) to 6.51 (July). Assuming 4hr could leave you way under powered in the winter but compared to more typical users who camp mostly April-October will report much higher output than you will see in the winter.
I think 10 to 25% is way low especialy for a stationary place they won't be towing home each time. I would still do double the recomendation for batteries this keeps the cycle depth even lower so better for the batteries and you have even more reserve if you there and you get a week of bad weathet.
I have 10 times my max daily use in battery for my camper, and emough solar to fill my max daily use by noon on a good day. I do a lot of bad weather and shaded camping with that one and two years ago with the normal deep cycles I found with 50% duty on the furnace I was realy getting worried on the 3rd night about the batteries staying over 50%. I was going below freezing each night and only just above in the day and I was camped in the trees while it rained for 3 days :R
