Bus Conversion-Refrigerator

[Khrysalis]

Greetings!

I have 1000 watts of solar. I am wanting to split this into two completely different systems.

400 watts. 2×100 amp hours lithium batteries and 1000 watt inverter to only power a 3.5 cubic foot freezer, but being used as a refrigerator by regulating the temperature. From what I Googled it said that the freezer uses 0.66kw per day, but is that accurate since the freezer doesn't technically stay on all day. It only comes on when the compressor kicks on correct? Not sure.
Do I need another charge controller?

for the 600 watts 40 Amp charge controller, I'm thinking 2000 watt inverter and 4×100 amp hour lithium smart batteries would be used for the rest of my DC/AC stuff. Puck lights, water pump, camera system, fantastic fans, charging phones etc.

I'm having a really hard time understanding and putting things together. Could use some help. Thank you.

The reason I'm splitting the system is because I already have two 100 amp hour battles that are lithium and purchased another lithium battery that is a smart lithium battery and can not put them together. So instead of starting all over wirh batteries going to split the system.

 

[HRTKD]

Batteries can coexist in the same system. It's not ideal, but it does work. It may be more work to have two distinct systems.

You could bring all the PV power into a set of common bus bars. Then use DC-DC chargers off the common bus bars to charge the separate battery systems. Just throwing that out as an idea.

 

[Rider]

400 watts. 2×100 amp hours lithium batteries and 1000 watt inverter to only power a 3.5 cubic foot freezer, but being used as a refrigerator by regulating the temperature. From what I Googled it said that the freezer uses 0.66kw per day, but is that accurate since the freezer doesn't technically stay on all day. It only comes on when the compressor kicks on correct? Not sure.
Do I need another charge controller?

I have a 3.5 cf freezer with an external temp controller to use as a fridge when camping. I use one 270W poly panel, a 30A SCC and a 100Ah AGM. It will run indefinitely, recharging fully even on a cloudy day. When testing, I only had a 45Ah battery, and it ran the fridge for 36 hours with no solar input. Overall, I calculated the fridge used about 10 watts per hour over a couple of days in 80-90*F temps.

For Camping

I wanted a small power system for camping, so I used a lot of information gleaned from Will's YouTube vids to put together a system. My main objective was to provide enough power to run a fridge and keep it compact. The Solar Charger: As I was walking thru BJs, I spotted a tiered toolbox that...

diysolarforum.com

 

[hidiyguy]

Like Rider, I did the same with a 3.8cf freezer to fridge conversion. Ran off one 260W panel and two 6V 210AH golf cart batteries. Worked great with no problems (and also ran 12V lighting, phone chargers, etc).

My freezer was rated at 197 KwH power use per year or about 540 Watts per day. With a fridge thermostat, on one test it used just over 300 watts per day with lows of about 70 and highs of about 90 (for this test it was warm at start, so would consume less if already cool). I'd expect that you'll use more power if the door is constantly opened but still well within the range of what 400 watts of panels and 200Ah of 12V lithium battery can support.

One lesson I learned is that there was a fairly high startup draw when turning on the fridge; believe I ended up with a 1200W inverter to handle it after an 800W inverter couldn't. Both were cheaper modified sine which could have also been a factor. Your 1000W inverter could be a risk factor, so if you can identify start up power surge (sorry, I'm no help on how), or if already purchased just use it and monitor to see if it trips.

For your use, I'd say one battery system, SCC, and inverter would be fine with less cost and complexity; I don't see you taxing the system at all with your planned loads.