Charge controller only works when the battery is already charged?

[Dingeling]

Experience level: Total electronics illiterate newbie

System:

• 130W Folding Solar Panel (2x 65W) with 12v/10A Charge Controller ZM9177 (https://www.soanar.com/store/category/344/product/zm9177.aspx)
• An older 12v N70ZZ Sealed Expanded Calcium MF Battery 600 CCA
• Smartphone with USB charging cable
• 12v 48W cooler

Connections:

• Solar panels are preconnected to the PV terminal of the CC
• Battery connects to the battery terminal of the CC with prewired cable with alligator clips
• Smartphone plugs into the USB charging port on CC
• Cooler connects directly to battery with cable with alligator clips

Issues:

1. When I arrived at the campground I setup the panels in full mid-summer sunlight. I connected the battery to the panels and the cooler to the battery. Everything seemed to be working fine, but by sunset (4-5 hours later), the battery was completely discharged. The next morning I setup the panels in full sunlight, but the CC seemed completely dead: none of the LEDs lit up, neither before nor after connecting the discharged battery, and nothing happened when I plugged in the USB cable to charge my phone. After packing up the panels I did some googling and read that the CC could be reset by leaving the solar panels covered and first connecting a charged battery before exposing the panels to sunlight. So, I charged the battery with my car using jumper leads while the engine was running. Sure enough, after connecting the charged battery the CC came back to life.
2. The CC is supposedly capable of charging 12v devices like smartphones via it's USB port, without a storage battery being connected, but it only seems to do so sporadically. Only on a couple of occasions has my phone indicated that it was charging when connected to the CCs USB port, and even then it would stop charging within a minute or so.

Questions:

1. What's the point of a solar charging system that only works if the connected storage battery is already charged?
2. If a storage battery should always be connected to a CC prior to connecting the solar panels, why would a portable system like this come with the panels prewired to the CC, knowing that the battery will regularly be connected and disconnected every time the system is relocated and stored away?
3. Any ideas why the USB port would only work sporadically and temporarily?

 

[HRTKD]

I have a PWM charge controller in my trailer that has been bulletproof for three years. I charge off of its USB port all the time, even when the sun is down. PWM controllers seem to be much more forgiving when it comes to connecting out of order. I see new trailers on the lot with no battery but an active PWM charge controller panel.

The controller may need a charged battery to initially determine the voltage of the system. But your issue #1 sounds like your controller just isn't working right.

 

[dragrty]

What voltage is your battery showing?? if its below the CC limits, this might be your issue

 

[mikefitz]

What's the point of a solar charging system that only works if the connected storage battery is already charged?

The controller needs battery power to function, providing the battery has some charge the system should work OK.

storage battery should always be connected to a CC prior to connecting the solar panels

This is the way things are with basic controllers, the designers of the system should have made this clear.

the USB port would only work sporadically and temporarily

not enough power to charge the battery from the solar

Your battery may not be in the best condition. Its basically a starter battery and if it has been in use for some time may only have a fraction of its capacity. The panels should deliver a maximum 7 amps under ideal conditions, full sun , no shade, in summer. You were perhaps only getting enough power to run the cooler.
I strongly suspect the battery is end of life.

Mike

 

[MrNatural22]

Experience level: Total electronics illiterate newbie

System:

• 130W Folding Solar Panel (2x 65W) with 12v/10A Charge Controller ZM9177 (https://www.soanar.com/store/category/344/product/zm9177.aspx)
• An older 12v N70ZZ Sealed Expanded Calcium MF Battery 600 CCA
• Smartphone with USB charging cable
• 12v 48W cooler

Connections:

• Solar panels are preconnected to the PV terminal of the CC
• Battery connects to the battery terminal of the CC with prewired cable with alligator clips
• Smartphone plugs into the USB charging port on CC
• Cooler connects directly to battery with cable with alligator clips

Issues:

1. When I arrived at the campground I setup the panels in full mid-summer sunlight. I connected the battery to the panels and the cooler to the battery. Everything seemed to be working fine, but by sunset (4-5 hours later), the battery was completely discharged. The next morning I setup the panels in full sunlight, but the CC seemed completely dead: none of the LEDs lit up, neither before nor after connecting the discharged battery, and nothing happened when I plugged in the USB cable to charge my phone. After packing up the panels I did some googling and read that the CC could be reset by leaving the solar panels covered and first connecting a charged battery before exposing the panels to sunlight. So, I charged the battery with my car using jumper leads while the engine was running. Sure enough, after connecting the charged battery the CC came back to life.
2. The CC is supposedly capable of charging 12v devices like smartphones via it's USB port, without a storage battery being connected, but it only seems to do so sporadically. Only on a couple of occasions has my phone indicated that it was charging when connected to the CCs USB port, and even then it would stop charging within a minute or so.

Questions:

1. What's the point of a solar charging system that only works if the connected storage battery is already charged?
2. If a storage battery should always be connected to a CC prior to connecting the solar panels, why would a portable system like this come with the panels prewired to the CC, knowing that the battery will regularly be connected and disconnected every time the system is relocated and stored away?
3. Any ideas why the USB port would only work sporadically and temporarily?

I may have missed something here but it sounds like since your panels are already connected to the charge controller and your connecting the battery next it is not a usual connection process. Battery always connects first to determine the operational voltage and then the panels last. ?
Maybe try keeping panels folded or covered to prevent any PV power, connect the battery to the charge controller then unfold/ uncover the panels.
I’m just guessing at this point. But as others have said the battery might be kaput and has too low a voltage stored.????
???

 

[Mex Rider]

I may have missed something here but it sounds like since your panels are already connected to the charge controller and your connecting the battery next it is not a usual connection process. Battery always connects first to determine the operational voltage and then the panels last. ?
Maybe try keeping panels folded or covered to prevent any PV power, connect the battery to the charge controller then unfold/ uncover the panels.
I’m just guessing at this point. But as others have said the battery might be kaput and has too low a voltage stored.????
???

1.Charge controllers, in general, will not charge fully discharged batteries for safety reasons. 2. Alligator clips are inadequate for charging connections. If you stop discharging before the battery is totally discharged your scc will recharge the battery without needing another charged battery