New to solar, starting small 50 watts / 50ah battery.

[Asalinas96]

Hello everyone,

This would be my first post here, I come from a technology background with some years of experience on the field. With computer systems being dependent on electricity, it seems solar was a good next stepping stone in an area that sparks some interest for me. Im looking to start with a very basic setup to first learn the fundamentals and once I have a much better understanding I can start scaling or starting from scratch with some better knowledge

I currently have a
50 watt renogy panel
50 AH LiTime 12v lithium battery
Renogy 10A wanderer charge controller
Renogy 700 Watt Inverter
Renogy Rs232 Bluetooth module for remote charge controller access

Main planned use is to provide interior LED lighting to a small shed (only powered via switch) / Outdoor Night floodlight LED lighting 30-75 Watts (6-8 night hours)

(possibly a 100/200 watt speaker amp with 2 outdoor speakers) for low/mid power music

I currently have a few connectors and mounts im awaiting to arrive, was considering purchasing 3 more 50 watt panels and another 50AH battery In the short future.

My next steps are figuring how to set up a safe system with fuses / heat shrink sealing terminals / correct use-cases... what not to do etc.

If anyone can provide any advice or things I need to consider I would appreciate it, thanks.

 

[Zapper77]

Sounds good to me.

 

[MisterSandals]

If anyone can provide any advice or things I need to consider I would appreciate it, thanks

With a small system, you can get started with what you have.
Connect the Rover to your battery and set it up with a lithium charge profile.
Then connect the panel and get some photons.

While you're messing with that you can get a fuse or breaker for your inverter:
700W inverter / 10V inverter cutoff / .85 efficiency = 82A
So a 12V 100A fuse or breaker will protect their to your inverter.
4AWG to your fuse/breaker and then to your inverter.

Have fun. Maker sure you disconnect solar before disconnecting the battery from your Rover (think of it as being powered by the battery voltage and never the solar voltage).

 

[Solarcabin Channel]

Generally you want at least twice as much solar watts as battery amp hours to get a full charge in 5-8 hours of good sunshine.

So for a 50Ah LFP you would want at least 100 watts of solar.

However, where you are not running a load all the time your system would work.

If you plan on expanding this in the future I would recommend 100 watt panels and 100Ah LFP batteries. Those are a better price per watt and amp hour and you will have fewer panels, batteries and wiring to mess with.

I have a 200 watt recharging station that is two 100 watt Renogy panels, a Renogy wanderer 30 Amp mppt and a 200Ah LFP that runs a 12 volt fridge/freezer full time and used for charging my ebike and gadgets and running lights. Occasionally I run a microwave and large tools off a 1500 watt inverter and that system.

I lived off grid for over 10 years with just a 400 watt system and you can do a lot with that. Renogy has a 400 watt kit with the controller you might want to look at.

Adding new batteries to old can cause problems down the road and LFP are not like flooded that will balance the whole bank so the fewer batteries in the bank the less headaches. Keep in mind LFP batteries won't charge below freezing and if you are using these in an uninsulated shed where they will get below freezing you may want to consider AGM batteries.

The controller and inverter is fused so you really only need a fuse on any DC direct plugs from the battery and I use a 30 amp inline fuse on direct DC lines. You can get those at any auto parts store.

Plug the battery in to the controller first and set it to LI and then plug in the panels to the controller. Connect the inverter to the battery and you are good good to go!

 

[pollenface]

My advice is to go bananas on the solar. Using a pwm scc you can expect roughly 70% of the available pv power reaching the battery.

Rule of thumb for sizing pv for pwm controllers is to keep the pv short circuit current (isc) under 80% of the current rating of the controller.

 

[mikefitz]

Renogy 700 Watt Inverter

If you can use all 12v directly powered lights and audio equipment, you will have a much greater efficiency in your system.
The standby power consumption of the inverter is 10 watts per hour, ( switched on), this is significant compared to solar and battery power.