small garage solar project

K

Kenbat

Member
Joined
Jul 26, 2018
Messages
32
Hi, I'm having trouble with a small project I've been working on. I have a 10w solar panel going through a cheap chinese 12v/10a charge controller into a 12v/24ah lead acid battery. I then have a cheap chinese 12v to 220-240v inverter with 2x 36w LED strip lights connected via a standard (UK) 3 pin plug.

Whenever I switch to lights on, they come on for half a second, then go off. I've made sure the battery is fully charged, and I've tried a standard lead-lamp, but the same thing happens.

Anything obvious that I'm missing?

Thanks
 
What wattage rating is the inverter ?

Can measure 240v ish on its output unloaded ?
 
I'd say the inverter is toast. Possibly a short in one, or more, of the FETs, or a blown capacitor.

Which chinesium devices do you have (both devices, to help us understand better your setup)?
 
Sean said:
What wattage rating is the inverter ?

Can measure 240v ish on its output unloaded ?
Click to expand...

Hi, thanks for your replies. The inverter is rated at 1950w, although I was using a little 100w inverter that somebody gave me, and that did the same thing. There is a guage on the new inverter that reads 240v ish when unloaded.

I've attached photos.

I've been collecting 18650s for a while and wanted to do a little garage light project before I start the big one! image_svanhs.jpg

image_almlkq.jpg
 
Is the inverter connected directly to the batteries, or is it connected to the load output on the charge controller (the Light bulb symbol)? If you are connecting through the charge controller, it's possible, most likely, the controller is overloading and shutting down.
Connect the inverter directly to the batteries, if you haven't already.

Those cheap controllers usually can't handle a high amp spike. The amps will ramp up momentarily when the lights, or other load, is connected to the inverter.
 
You don't say if it has ever worked? Running a big inverter like that and taking 72W of lights is a lot. So without more info best guess is when the inverter starts draining the battery the voltage dips below it's cutoff voltage and turns the inverter off. Troubleshoot one thing at a time. Plug the inverter into your car battery, and see if that works. Then work backwards and plug a voltmeter on your solar battery to see if your voltage ever dips below 11V. Try a smaller load?
 
So I've finally got around to doing some troubleshooting. I've connected the battery straight to the inverter and plugged my LED strip lights into it. This works fine. I've measured 12.8v on the load output of the charge controller.

If I connect the charge controller to the inverter it still powers my lights for half a second then trips out the inverter.

Any suggestions please?
 
Kenbat said:
So I've finally got around to doing some troubleshooting. I've connected the battery straight to the inverter and plugged my LED strip lights into it. This works fine. I've measured 12.8v on the load output of the charge controller.

If I connect the charge controller to the inverter it still powers my lights for half a second then trips out the inverter.

Any suggestions please?
Click to expand...


image_qqjegg.jpg


Are you connecting the inverter to the Yellow circle connectors, or the Red circle? If the Red, then this is why you are having issues. That is a very low current circuit in the controller. That's not the full load circuit.
Connect the inverter directly to the batteries and let the charger controller only control the charge to the batteries.
Even though the controller "says" that those connectors are for the load, they can't handle the amp draw the inverter pulls on surge. That port would work just fine for non-surge devices like lights, USB chargers, small DC fans, etc.
 
Thanks so much for your help, I will try that. Just waiting for it to cool down a little it's 31 degrees c here. Not used to it in the UK!

That worked a treat, thanks very much for your help Korishan. Onwards and upwards!
 
Although that solution worked, my battery is draining overnight. Do I just need to put a diode on positive feedback from solar panel?
 
Interesting. The charge controller "should" have a diode in it to prevent backfeeding at night. Are you sure the batteries drained because of the panels, or did the inverter drain them?

You could put a diode on the panel side and see what happens.
 
Just make sure to add proper fusers or breakers . Happy it works now
 
Are you leaving the inverter running over night too (it'll drain the batteries) or just powering up the inverter when you use the lights? (this is what I'd do)
 
Hi, thanks for all your replies. When I went to put a diode on the panel side of the system, I realised that I'd already put one in ages ago! Doh! I think the logical explanation is that the inverter is draining the battery as suggested by Redpacket. I wanted the system to work so that I just flipped a light switch when I went in the garage. The inverter is half way into the garage so it kind of defeats the object in a way.
Perhaps I could put a switch between the battery and inverter and mount this on the wall as I enter the garage. I think that may be the solution.
 
Or Use lights that are designed for battery voltage and get rid of the inverter in the equation?
 
daromer said:
Or Use lights that are designed for battery voltage and get rid of the inverter in the equation?
Click to expand...

yes, that would have been sensible! It was more of an experiment with some bits and bobs that I had, so that I could learn from it. I plan to build a bigger system to power part of the house at some point.
 
You must log in or register to reply here.
Back
Top