Pwm charge controller getting hot

[Damil 1776]

Howdy, it is HOT
I have a cheap 30amp pwm charge controller hooked to 4x100 watt panels running 12v and three ancient lead acid batteries, hooked up. It has been over 100 for the last four days, the charge controller has started heating up a lot, I unhooked it when it reached 120f with a fan on it, I could smell electric death from the controller
I have rolled my pennies and ordered another cheap controller, yes I know mppt would be better, or even a better pwm, but life is life, I have to make do with what I can.
My question, I have an old heat sink that fits the back of the controller perfectly, the back of the charge controller is steel, I did not design it , if I sand the paint off slap on some homemade thermal paste and connect the heat sink to the panel will it actually conduct enough heat away from the controller, or should I just Uninstall the back panel and rest it on the tabs that touch the back panel,

 

[GLC]

You did not say what amps and volts that your panels are producing. Also what is the watts and voltage max on your controller?

 

[Damil 1776]

You did not say what amps and volts that your panels are producing. Also what is the watts and voltage max on your controller?

Sorry 4 pannels pushing 23 amps max 30 amps charge controller 390 watts at 12 volt

 

[GLC]

Sorry 4 pannels pushing 23 amps max 30 amps charge controller 390 watts at 12 volt

Ok, good info, what is the controller specifications. Max watts and volts on controller? Guessing panels wired in parallel?

 

[Damil 1776]

Ok, good info, what is the controller specifications. Max watts and volts on controller? Guessing panels wired in parallel?

 

[Damil 1776]

Yes wired on parallel

 

[GLC]

Ok, max controller watts is 390. Max volts on controller is 50 volts. How are your panels wired? Series or parallel. Have you checked voltages and amps on the controller with a clamp meter? In other words, what are the panels really putting out? I have a hard time trusting pwm controllers.

 

[GLC]

Are these batteries hooked up to an inverter. If so how many amps are you trying to pull out.

 

[A.Justice]

23-30a on a 30a rated cheaper PWM controller is redlining it. For the Chinese PWM controllers, I would oversize by at least 40% to keep things cool.

 

[Damil 1776]

Are these batteries hooked up to an inverter. If so how many amps are you trying to pull out.

Yes they are hooked to a 1500 w inverter never pull more then a 5 Amp spike with 3 Amp steady.

 

[Damil 1776]

23-30a on a 30a rated cheaper PWM controller is redlining it. For the Chinese PWM controllers, I would oversize by at least 40% to keep things cool.

Thank you

 

[Damil 1776]

Ok, max controller watts is 390. Max volts on controller is 50 volts. How are your panels wired? Series or parallel. Have you checked voltages and amps on the controller with a clamp meter? In other words, what are the panels really putting out? I have a hard time trusting pwm controllers.

Wired in parallel voltage never goes above 19v my cheap ass multimeter is fused at 10 Amp I have checked each panel and in max sun 4.8 amps max, the cheap controller has an Amp meter, I do not trust it either but it never shows over 19.4 amps

 

[GLC]

Wired in parallel voltage never goes above 19v my cheap ass multimeter is fused at 10 Amp I have checked each panel and in max sun 4.8 amps max, the cheap controller has an Amp meter, I do not trust it either but it never shows over 19.4 amps

I tend to lean on crappy controller and possibly pulling too many amps at one time with a small inverter. Anything with a high in rush you have installed? Still leaning on a crappy controller.

 

[Damil 1776]

All I run is a fridge and two fans, only one fan when the fridge is running, guess I will just run the fridge and no fan until it cools down a bit. Probably the excess heat making the fridge work harder, any idea on the heat sink idea?

 

[GLC]

All I run is a fridge and two fans, only one fan when the fridge is running, guess I will just run the fridge and no fan until it cools down a bit. Probably the excess heat making the fridge work harder, any idea on the heat sink idea?

Any time you can add an extra heat sink, it is good. But if the controller is crap, you probably will not accomplish a lot.

 

[pollenface]

You can add a heatsink if you feel it necessary but pwm controllers are able to work at full capacity in very warm conditions.

My Epever vs3024au states 85°c max operating temp at full capacity.

 

[12VoltInstalls]

You can add a heatsink if you feel it necessary but pwm controllers are able to work at full capacity in very warm conditions.

My Epever vs3024au states 85°c max operating temp at full capacity.

That- and since it’s a cheap controller just buy a second one and run only two panels per controller- half the organically created heat- or get the Epever and be done with it. Imho

BTW if you use longer mounting screws and a couple nuts to space the pwm off the mounting surface you’ll be better off.

 

[gelmjw]

Try 300W solar by disconnecting 1 panel.