Problem with 100 watt panels or something else. Random issue
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Blindowl1234
Registered Users Posts: 54 ✭✭
About 5 years ago I put in a handful of solar lights outside, and in the house for use at night. Basically 15-20 watts of accent lighting. System is 12 volt and has 2- 100 watt Grape panels. Cheap 30A Chinese controller BSC3048. Last summer I noticed one of the panel surfaces appears to have surface cracks all over it. It was still working fine so I left it alone. Recently the lights which run for 6 hours after dark, started cutting on and off at a more or less random interval. This only happens after they've been working fine for about 3 out of the 6 hours. The lights come on for say around 2 minutes or so, then off for 1 minutes then repeat the cycle. That's just a guess as I've not actually timed it. At the end of the 6 hour programmed cycle they shutoff as normal for the night. I also noticed it seemed to be a problem when it rained. I figured water was shorting out the panel that was cracked. Well that's not it either, as I disconnected the cracked panel, and that night the problem was still there. It's random and I have no idea what to check next. I plan on replacing the bad panel which is currently unhooked. But its not the problem as far as I can tell. I'm wondering if possibly the controller is starting to have random issues? Almost appears that something is telling the panels its daylight when its dark...only randomly though. Any ideas? Don't want to just randomly start replacing parts. However its baffling me.
Comments
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Do you have a volt meter you can measure the battery voltage with?
-BillNear San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset -
11 AM light rain and cloudy. Batteries show 13.2 volts. A few hours and they should be at float voltage
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Given poor solar conditions--It does sound like the system is capable of charging...
Just check the battery voltage when things "go south". In general, the solar charge controller/light controller should be responding to battery voltage. Both when controlling lights (low voltage) and when charging (actual charging of ~14.4 volts or so, and around 13.6 volts or so when floating--charging is completed (high voltage).
It is very possible you have two problems. The solar panel possible failure, and the battery just getting old (5 years of daily cycling is not a "bad" battery life)--As well as the battery getting stressed from the (possible) panel failure.
Eventually, you may want to get a simple AC+DC current clamp DMM (digital multi-meter)--If you don't have one yet.
https://www.amazon.com/UNI-T-Digital-Handheld-Resistance-Capacitance/dp/B0188WD1NE
The above is pretty inexpensive (for a current clamp meter) and will do pretty much any basic testing you need (voltage, current, resistance).
Once you have a DC Current Clamp meter, you can check the current from each solar panel and see if your panel(s) is good or not (test under full sun, each panel, and then compare current between them).
-BillNear San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset -
BB. said:Given poor solar conditions--It does sound like the system is capable of charging...
Just check the battery voltage when things "go south". In general, the solar charge controller/light controller should be responding to battery voltage. Both when controlling lights (low voltage) and when charging (actual charging of ~14.4 volts or so, and around 13.6 volts or so when floating--charging is completed (high voltage).
It is very possible you have two problems. The solar panel possible failure, and the battery just getting old (5 years of daily cycling is not a "bad" battery life)--As well as the battery getting stressed from the (possible) panel failure.
Eventually, you may want to get a simple AC+DC current clamp DMM (digital multi-meter)--If you don't have one yet.
https://www.amazon.com/UNI-T-Digital-Handheld-Resistance-Capacitance/dp/B0188WD1NE
The above is pretty inexpensive (for a current clamp meter) and will do pretty much any basic testing you need (voltage, current, resistance).
Once you have a DC Current Clamp meter, you can check the current from each solar panel and see if your panel(s) is good or not (test under full sun, each panel, and then compare current between them).
-Bill -
Blindowl1234 said:BB. said:Given poor solar conditions--It does sound like the system is capable of charging...
Just check the battery voltage when things "go south". In general, the solar charge controller/light controller should be responding to battery voltage. Both when controlling lights (low voltage) and when charging (actual charging of ~14.4 volts or so, and around 13.6 volts or so when floating--charging is completed (high voltage).
It is very possible you have two problems. The solar panel possible failure, and the battery just getting old (5 years of daily cycling is not a "bad" battery life)--As well as the battery getting stressed from the (possible) panel failure.
Eventually, you may want to get a simple AC+DC current clamp DMM (digital multi-meter)--If you don't have one yet.
https://www.amazon.com/UNI-T-Digital-Handheld-Resistance-Capacitance/dp/B0188WD1NE
The above is pretty inexpensive (for a current clamp meter) and will do pretty much any basic testing you need (voltage, current, resistance).
Once you have a DC Current Clamp meter, you can check the current from each solar panel and see if your panel(s) is good or not (test under full sun, each panel, and then compare current between them).
-Bill -
14/2 is pretty skimpy. Even if the wire carries the current safely from 300 Watts, with 12 V panels you probably don't have much tolerance for voltage drop which will reduce ability to charge your battery. So worth it to run 12/2, it'll make your system run better.
Remember to fuse everything, especially on the battery side - even 12 Volts can cause fires if wires short somehow they can glow red hot for just long enough to melt vinyl siding and start a fire.Offgrid in cloudy PNW
MacGyver'ed museum collection of panels, castoff batteries and generators - ready for state of art system install .... parade of surviving and dead generators: H650, Ryobi 900, Briggs and Scrap Iron 2000, H2200, H3000, Kubota 3500, Kubota 4500, Onan 7500
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If you place a third panel in parallel and with your 14AWG wire you would have losses at ~21%. That's expensive. Getting to ~2% loss or less should be the goal. Even with 12AWG wire you will be losing ~13% of your precious gathered energy. 13% loss is better than 20% loss but 13% is still very high.
Here's a voltage drop calculator: https://www.southwire.com/calculator-vdrop
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SteveK said:If you place a third panel in parallel and with your 14AWG wire you would have losses at ~21%. That's expensive. Getting to ~2% loss or less should be the goal. Even with 12AWG wire you will be losing ~13% of your precious gathered energy. 13% loss is better than 20% loss but 13% is still very high.
Here's a voltage drop calculator: https://www.southwire.com/calculator-vdrop -
Graham Parkinson said:14/2 is pretty skimpy. Even if the wire carries the current safely from 300 Watts, with 12 V panels you probably don't have much tolerance for voltage drop which will reduce ability to charge your battery. So worth it to run 12/2, it'll make your system run better.
Remember to fuse everything, especially on the battery side - even 12 Volts can cause fires if wires short somehow they can glow red hot for just long enough to melt vinyl siding and start a fire. -
Well, to get to 2% you'd need to stuff a 3awg wire below the siding.....def not suggested. I'd be OK with 2 fused 10AWG in parallel @ 30'. This would get you to ~4%. Need to keep THHN out of the Sunlight though.
That is if we are throwing NEC codes out the window anyways.....
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Steve is meaning that for safety and to meet code, DC wire inside a house (ie under the siding) needs to be in metal conduit. Metal conduit will not burn and ignite surrounding materials if a short occurs.
Offgrid in cloudy PNW
MacGyver'ed museum collection of panels, castoff batteries and generators - ready for state of art system install .... parade of surviving and dead generators: H650, Ryobi 900, Briggs and Scrap Iron 2000, H2200, H3000, Kubota 3500, Kubota 4500, Onan 7500
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SteveK said:Well, to get to 2% you'd need to stuff a 3awg wire below the siding.....def not suggested. I'd be OK with 2 fused 10AWG in parallel @ 30'. This would get you to ~4%. Need to keep THHN out of the Sunlight though.
That is if we are throwing NEC codes out the window anyways..... -
Second mortgage
At least it wasn't a first mortgage then we have to do a home inspection: "Quick, hide the batteries!"
I'm with you on cost. Every day I try to convince myself that less is more 'cept my lenders just don't seem to agree.....
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