Re: Planning to convert a 6x12 cargo trailer.
Posted: Thu Jul 29, 2021 6:02 am
That's true.
I think I've decided on the battery voltage. Six cells in series will give me the voltage range I need for the solar charge controller. Also, I picked out a mini fridge I like, and contacted the manufacturer about its startup current. They were kind enough to answer, and it looks like the fridge can draw up to 6A when it first starts up, but runs on a little less than 1A.
The 500W inverter I was looking at may or may not work for that. I asked that manufacturer about it and didn't get an answer. So I'm looking at a slightly larger 600W inverter. Also pure sine. It claims to be able to handle 1200W of peak current, though the reviewers don't agree on whether that's actually true. Maybe it depends on how long the peak lasts. But if the fridge only peaks at 720W, hopefully that will work. Just have to try it and find out.
I've also been looking at stuff for the grid connection. I'd like to use a surge protector, but they don't seem to make them for 20A hookups. I've been thinking I could get by with just a 20A hookup, but maybe I should bump it up to 30A. I plan to have two 15A breakers inside the trailer. Even if I ran everything at the same time, the current would still be less than 20A. Of course the microwave would only be used for a few seconds at a time. I don't think 700W is enough to do any actual cooking. Just the convenience of heating things up a little. For cooking we'll have propane and propane accessories.
I put a lot more detail in my circuit diagram.
After adding up power for all the things running off the battery, I made an estimate of how long each device would run per day. I used the kW/year rating for the mini fridge. Looks like the fridge will take up 2/3 of the power consumption. Haven't taken conversion inefficiencies into account yet, but It looks like about 1,300 Wh may be used per day. The battery should have about 1,500 Wh, so it should last up to a day without any charging. If we need to conserve power, the fridge could just be turned off, and we can put a tub of ice in it. That could stretch the battery across maybe 3 days. Also, we'll have solar, but sun is never guaranteed.
I think I've decided on the battery voltage. Six cells in series will give me the voltage range I need for the solar charge controller. Also, I picked out a mini fridge I like, and contacted the manufacturer about its startup current. They were kind enough to answer, and it looks like the fridge can draw up to 6A when it first starts up, but runs on a little less than 1A.
The 500W inverter I was looking at may or may not work for that. I asked that manufacturer about it and didn't get an answer. So I'm looking at a slightly larger 600W inverter. Also pure sine. It claims to be able to handle 1200W of peak current, though the reviewers don't agree on whether that's actually true. Maybe it depends on how long the peak lasts. But if the fridge only peaks at 720W, hopefully that will work. Just have to try it and find out.
I've also been looking at stuff for the grid connection. I'd like to use a surge protector, but they don't seem to make them for 20A hookups. I've been thinking I could get by with just a 20A hookup, but maybe I should bump it up to 30A. I plan to have two 15A breakers inside the trailer. Even if I ran everything at the same time, the current would still be less than 20A. Of course the microwave would only be used for a few seconds at a time. I don't think 700W is enough to do any actual cooking. Just the convenience of heating things up a little. For cooking we'll have propane and propane accessories.
I put a lot more detail in my circuit diagram.
After adding up power for all the things running off the battery, I made an estimate of how long each device would run per day. I used the kW/year rating for the mini fridge. Looks like the fridge will take up 2/3 of the power consumption. Haven't taken conversion inefficiencies into account yet, but It looks like about 1,300 Wh may be used per day. The battery should have about 1,500 Wh, so it should last up to a day without any charging. If we need to conserve power, the fridge could just be turned off, and we can put a tub of ice in it. That could stretch the battery across maybe 3 days. Also, we'll have solar, but sun is never guaranteed.