Floodlight flickering

[joelonly]

Bad charge controller?
Not really enough info to determine.
Could be a bad panel
Undersized panel for the load
Insufficient insolation to charge battery

Thanks

[PNjunction]

Sorry about this - I think I just figured it out.

You are using the controller's load terminals to program the light on/off durations.

That in itself may be an issue at 2.7a draw from the load terminals. If so, then use of a relay which then controls the dc bulb and still allow for programmable lighting duration may be in order.

OR, if the load terminals can handle that, it may just be a simple matter of your battery not getting charged enough daily, and the voltage is too low for the dc bulb to operate without flickering. If you've been doing this for a long time, the battery may be sulfated, complicating matters further.

Grab a voltmeter, and measure the voltage of the battery terminals when it is flickering.

I've got a feeling that your best bet regardless is to double the size of your paneling, and of course make sure your CC can handle that.

While my previous suggestion to use an AC led bulb and a quality simple inverter would definitely save you power, you'd lose the automation and have to turn off the bulb and inverter manually. Forget to turn it off, or just turn off the bulb and not the inverter, would drag the battery down to 10.7v typically before the auto cutoff activates - which is not a good thing to do.

[PNjunction]

This is interesting. Made me pull out the pencils for napkin-calc and a propose better solution than the dc bulb, and use an AC inverter with an ac led flood instead! Bear with me as I geek out..

I looked up a 30w DC driven led flood (golden gadgets) and see that true enough, it pulls 30w. Rated at 2.75a current at 12v dc.

However, if you were to run an "equivalent" 30w ac flood led, (GE PAR38 typical) that only pulls 12w in reality, and using a high-efficiency low wattage inverter, even a simple Samlex MSW, that would be about 12w/10 (samlex formula) = 1.2a at the terminals. That's a bit more than 50% better than the dc-driven led, even with the inverter!

I never thought about that as I just assumed that dc-driven bulbs were more efficient than ac driven ones. Wow.

You may want to look into that. Plus we have some issues from the napkin calc:

((50ah batt * 12v) / 2) = 300 usable watts reaching 50% DOD.

If you use that 30w flood at night for 10 hours, you are done right at 10 hours.

So now you have 25ah (plus about 10-15% to account for recharge inefficiency) - lets call it 28ah needed to return daily....

50w panel / 18v = 2.7A under absolute best conditions....

This would take 28 / 2.7 = 10.3 hours of charging daily, which nobody has in real-world terms of solar insolation. (differs from just sunrise to sunset)

If this is the case of running it nightly for 8 or more hours, I'd DEFINITELY beef up your panel to at least 100 watts or look into the AC driven led bulb that is actually more efficient with a *quality* high-efficiency low wattage inverter.

[Mike90250]

My bet is on the LED driver circuit being bad, overheating, or a bad wire connection. Flicker is not caused by battery, unless it's a rare intermittent connection in the cells.

It could be the solar controller LOAD terminal is overloaded by a 30W load too.

[Naptown]

Bad charge controller?
Not really enough info to determine.
Could be a bad panel
Undersized panel for the load
Insufficient insolation to charge battery

[joelonly]

Anyone can help me? i have 50W off grid solar system, 12V/30W LED floodlight directly connected to the solar controller. 50Ah deep cycle battery.
New battery only lasted for 6 months, the LED floodlight flickering. What is the possible problem
Thanks

Joelonly