Pwm solar controller goes out

[MMSPAAS]

Hello, I made a off grid stable for our horses. We have a jinko solar tiger 355wp n-type on the roof and a cheap pwm solar charge controller 30amps (picture) and 2x 92amps battery’s in parallel so 12v’s.
When the sun is up and shining nice, the pwm stops working ( display goes out!) and thus stops charging the battery’s (also tried one battery, same issue).
What’s the problem with the system? Please help!

 

[grizzzman]

What voltage can your controller handle? What is the panel voltage?

 

[MMSPAAS]

The sticker on the controllers says pv Max 50v, and the panel (see picture).

 

[Bud Martin]

Your PV panel Voltage is way too high for 12V PWM SCC, 17 ~18Vmp is typical for 12V PWM system.
Your SCC user manual should tell you what Voltage it should be.

 

[clarkpeacock]

Hello, I made a off grid stable for our horses. We have a jinko solar tiger 355wp n-type on the roof and a cheap pwm solar charge controller 30amps (picture) and 2x 92amps battery’s in parallel so 12v’s.
When the sun is up and shining nice, the pwm stops working ( display goes out!) and thus stops charging the battery’s (also tried one battery, same issue).
What’s the problem with the system? Please help!

View attachment 86820

Amazon would suggest maximum 36v panel voltage for this controller for a 24v battery or 18v for 12v battery. As previous post states, yours is way too high!

https://www.amazon.co.uk/dp/B086WNCCX3/ref=cm_sw_r_apan_glt_i_BQ1HCZPP5YX3P385M5Q6

 

[MMSPAAS]

Your PV panel Voltage is way too high for 12V PWM SCC, 17 ~18Vmp is typical for 12V PWM system.
Your SCC user manual should tell you what Voltage it should be.

The manual was all in Chinese.
Rookie mistake, I am all new to this. My apologies. What could be a better SCC for this panel? Is a Victron smart solar 75-10 a good option?

 

[mikefitz]

355 watts of panel in theory requires a 30 amp controller with a 12v system and MPPT controller. From the input Victron range a 100/30 would be suitable.

Your existing PWM controller should have functioned and given a maximum output of around 10 amps. As you realise its a fake MPPT but is designed as a 12 or 24 volt controler so should have tolerated your panel volts.

Mike

 

[MMSPAAS]

355 watts of panel in theory requires a 30 amp controller with a 12v system and MPPT controller. From the input Victron range a 100/30 would be suitable.

Your existing PWM controller should have functioned and given a maximum output of around 10 amps. As you realise its a fake MPPT but is designed as a 12 or 24 volt controler so should have tolerated your panel volts.

Mike

That were my simple thoughts also when I purchased the scc, but it’s sadly not the case.
Which controller is also suitable with lower price point as the Victron?

 

[Rednecktek]

Which controller is also suitable with lower price point as the Victron?

What price point? EPEver and Rich Solar are good more budget choices, HQST or Newpowah will be a little cheaper yet and do the job of turning Solar DC into Battery DC if you don't want any of the fancy features like WiFi and Bluetooth.

The best rule of thumb I can give you is that if it has USB ports, it's NOT a real MPPT controller.

 

[MMSPAAS]

What price point? EPEver and Rich Solar are good more budget choices, HQST or Newpowah will be a little cheaper yet and do the job of turning Solar DC into Battery DC if you don't want any of the fancy features like WiFi and Bluetooth.

The best rule of thumb I can give you is that if it has USB ports, it's NOT a real MPPT controller.

Thank you very much for the info so far. MPPT is not a must, pwm is also fine. But that’s not a option in my case?

 

[Rednecktek]

Thank you very much for the info so far. MPPT is not a must, pwm is also fine. But that’s not a option in my case?

With a 355w panel, MPPT really is a MASSIVE difference.

PWM works by cutting the panel voltage off at the battery voltage, so your controller will never use anything over 13.5-ish volts. The panel can only produce 10.3a, so 10.3a 2 13.5v = 139w being the maximum your SCC can use. Even if you had a 1000a PWM controller, your panel can only produce 10.3 so you'll never see over 10.3a, or about 140w in peak laboratory conditions. That's over half your panel's capacity left on the table.

MPPT on the other hand will take whatever Wattage the panel can produce and through the magic of DC-DC converting change that higher voltage from the panel to usable amperage going to the battery. So, now that 355w panel divided by 13.5v = 26.3a of charging available to the battery.

Yes, it's going to cost you in the neighborhood of $100 to get even a super basic MPPT, but you're going to get about 255% more power out of your panel.

 

[sunshine]

MPPT is not a must, pwm is also fine. But that’s not a option in my case?

If you can get a current reading just before the CC cuts out, and feel the temp at the back, may determine why the CC is failing at full sun.
Another PWM in parallel may meet your needs.

 

[MMSPAAS]

With a 355w panel, MPPT really is a MASSIVE difference.

PWM works by cutting the panel voltage off at the battery voltage, so your controller will never use anything over 13.5-ish volts. The panel can only produce 10.3a, so 10.3a 2 13.5v = 139w being the maximum your SCC can use. Even if you had a 1000a PWM controller, your panel can only produce 10.3 so you'll never see over 10.3a, or about 140w in peak laboratory conditions. That's over half your panel's capacity left on the table.

MPPT on the other hand will take whatever Wattage the panel can produce and through the magic of DC-DC converting change that higher voltage from the panel to usable amperage going to the battery. So, now that 355w panel divided by 13.5v = 26.3a of charging available to the battery.

Yes, it's going to cost you in the neighborhood of $100 to get even a super basic MPPT, but you're going to get about 255% more power out of your panel.

It is not that critical that I get the most out of the system. It’s just for charging the battery’s. So the boss can use her lights in the evening, and her Chinese ip camera. We have 3 x 12v/18w lights. And the are max one our per day on.
So what can also be a pwm option in our case. Or will the cost of purchase not be that different?

 

[MMSPAAS]

If you can get a current reading just before the CC cuts out, and feel the temp at the back, may determine why the CC is failing at full sun.
Another PWM in parallel may meet your needs.

Sorry commented to fast, what do you mean “another pwm in parallel”

 

[MMSPAAS]

With a 355w panel, MPPT really is a MASSIVE difference.

PWM works by cutting the panel voltage off at the battery voltage, so your controller will never use anything over 13.5-ish volts. The panel can only produce 10.3a, so 10.3a 2 13.5v = 139w being the maximum your SCC can use. Even if you had a 1000a PWM controller, your panel can only produce 10.3 so you'll never see over 10.3a, or about 140w in peak laboratory conditions. That's over half your panel's capacity left on the table.

MPPT on the other hand will take whatever Wattage the panel can produce and through the magic of DC-DC converting change that higher voltage from the panel to usable amperage going to the battery. So, now that 355w panel divided by 13.5v = 26.3a of charging available to the battery.

Yes, it's going to cost you in the neighborhood of $100 to get even a super basic MPPT, but you're going to get about 255% more power out of your panel.

Is this one a option?
Renogy 20A 12/24 V MPPT zonneregelaar zonnepaneel laadregelaar met LCD-scherm https://www.amazon.nl/dp/B01MRWTAB5...t_i_PT2VMWGAP56S2ZK7161A?_encoding=UTF8&psc=1

 

[mikefitz]

The blue PWM controller you used, seems, from data given for 'clones', to only be rated up to 28 volts for a 12 volt system.

It may even work with a panel rated at 22 volts maximum.

The lowest cost MPPT available in the UK is the Tracer/Epever XTRA 2210N, although only 20 amps output is rated for up to 360 watts input, cost around £ 70. ( Bimblr Solar)
Since your power requirements are small this should be more than enough.

Mike

 

[MMSPAAS]

The blue PWM controller you used, seems, from data given for 'clones', to only be rated up to 28 volts for a 12 volt system.

It may even work with a panel rated at 22 volts maximum.

The lowest cost MPPT available in the UK is the Tracer/Epever XTRA 2210N, although only 20 amps output is rated for up to 360 watts input, cost around £ 70. ( Bimblr Solar)
Since your power requirements are small this should be more than enough.

Mike

Mike thank you very much for your reply, I wil take a look!

 

[sunshine]

what do you mean “another pwm in parallel

The 30 amp PWM would not be able to handle the amperage the panel puts out, nor would a 20 amp mpp CC. A 40amp MPP CC would be better.
Sometimes a smaller CC than the panels output can be used but the load going into two 92ahr battery would overload them.

You do have other low cost alternatives.
1) de-tune the panel by bridging one of the diodes in the box at the back of panel giving a Voc of 27v and 240watts which your PWM may be able to handle.
or
2) Hacking the panel to get 2 X 180watt 20 Voc panels....see youtube for instructions. This is what I do.
You would be able to use your PWM for one side but need another for both.

 

[mikefitz]

30 amp PWM would not be able to handle the amperage the panel puts out,

Why, its a 11 amp panel maximum?

I suspect the existing controller is failing due to voltage.

Mike

 

[sunshine]

I suspect the existing controller is failing due to voltage.

That is the first assumption made...but is it correct?
I really doubt if these generic PWMs have a high voltage disconnect (my assumption). Failure by high voltage probably means no coming back.
The OP stated "When the sun is up and shining nice, the pwm stops working ( display goes out!)" To find out more I asked "If you can get a current reading just before the CC cuts out, and feel the temp at the back, may determine why the CC is failing at full sun."... so as to remove any doubts.