Solar Charge controller

[clarko2000]

Hi, I've just bought a couple of second hand Sanyo solar panels 190w.

Nominal output Pmpp: 190 [W]
Max. power tolerance: +10/-5 [%]
Max. Voltage system: 760 [V]
Nominal Voltage Umpp: 54,8 [V]
Nominal current Impp: 3,47 [A]
Open circuit voltage Uoc: 67,5 [V]
Short circuit current Isc: 3,75 [A]
Temperature coefficient of open circuit Voltage Uoc: -169 [mV / °C]
Temperature coefficient of short circuit current: 0,86 [mA / °C]
Temperature coefficient Output: -0,3 [% / °C]
Cell conversion efficiency: 18,5 [%]
Module conversion efficiency: 16,1 [%

Ive tested them and they seem to be fine. I connected the charge controller (10amp) that I got off ebay. What I want to know is it normal for the charge controller to get quite hot. It has a metal rear panel and it got pretty hot while I was testing it.

Thanks for the advice in advance.

Paul

[Sunking]

I bet it is hot. What battery voltage are you running? A 10 amp MPPT controller can only handle 120 watts input on a 12 volt battery or 240 watts on a 24 volt battery. You have 380 watts which means you need a 40 amp controller for 12 volt battery or 20 amps on 24 volt battery.

What you have is a PWM controller and only passing 7 amps on a 12 volt battery or 84 watts and the controller is burning off 300 watts as heat.

Now you know why it is running hot, you are burning it up. You got what you paid for. You have grid tied panels, and with Grid tied panels you must use a MPPT controller. Not a cheap PWM controller from Flea Bay.

[clarko2000]

I bet it is hot. What battery voltage are you running? A 10 amp MPPT controller can only handle 120 watts input on a 12 volt battery or 240 watts on a 24 volt battery. You have 380 watts which means you need a 40 amp controller for 12 volt battery or 20 amps on 24 volt battery.

What you have is a PWM controller and only passing 7 amps on a 12 volt battery or 84 watts and the controller is burning off 300 watts as heat.

Now you know why it is running hot, you are burning it up. You got what you paid for. You have grid tied panels, and with Grid tied panels you must use a MPPT controller. Not a cheap PWM controller from Flea Bay.

Thanks for the quick reply Sunking! Im running a 12v 75ah battery. Look, Im new to all this so its a bit of trial and error at the moment. Sorry for not being clear, I DID buy 2 190w panles but I was only using ONE with the charge controller. I was only running 1 x 190w panel to the charge controller. But even that sounds like it is too much for the charge controller?
I did buy a 10amp MPPT charge controller. I thought that would be sufficient as the max amp of the panel is stated as being 3.47amp max. Surely that charge controller is fine for one panel??
Forgive my ignorance I am new to all this BUT very keen to learn. Hopefully without killing myself.

[Wy_White_Wolf]

Thanks for the quick reply Sunking! Im running a 12v 75ah battery. Look, Im new to all this so its a bit of trial and error at the moment. Sorry for not being clear, I DID buy 2 190w panles but I was only using ONE with the charge controller. I was only running 1 x 190w panel to the charge controller. But even that sounds like it is too much for the charge controller?
I did buy a 10amp MPPT charge controller. I thought that would be sufficient as the max amp of the panel is stated as being 3.47amp max. Surely that charge controller is fine for one panel??
Forgive my ignorance I am new to all this BUT very keen to learn. Hopefully without killing myself.

MPPT controllers work as DC-DC converters. It doesn't matter that the panel only puts out 3.47 amps. The Controller can change that to 190W/12V = 15.83 Amps. So you need at least a 20 Amp MPPT controller.

WWW

[SunEagle]

Thanks for the quick reply Sunking! Im running a 12v 75ah battery. Look, Im new to all this so its a bit of trial and error at the moment. Sorry for not being clear, I DID buy 2 190w panles but I was only using ONE with the charge controller. I was only running 1 x 190w panel to the charge controller. But even that sounds like it is too much for the charge controller?
I did buy a 10amp MPPT charge controller. I thought that would be sufficient as the max amp of the panel is stated as being 3.47amp max. Surely that charge controller is fine for one panel??
Forgive my ignorance I am new to all this BUT very keen to learn. Hopefully without killing myself.

Usually those cheap MPPT controllers you find on eBay are fake and are really PWM type. Look into a Morningstar or Solar Boost. Just make sure the DC input voltage and total panel wattage rating of the CC works for your Sanyo panels.

[clarko2000]

MPPT controllers work as DC-DC converters. It doesn't matter that the panel only puts out 3.47 amps. The Controller can change that to 190W/12V = 15.83 Amps. So you need at least a 20 Amp MPPT controller.

WWW

Thanks WWW. Maths was always my weak point at school. And electrics uses a lot! OK, so, need to buy a new MPPT controller.

I'll get there in the end! This site is excellent, thanks for the advice.

Clarko

[Wy_White_Wolf]

One other note. Hope that's an AGM battery or it'll be short lived. 15.8 amps would put you slightly above a C/5 charge rate. An AGM should be able to handle that but a flooded lead acid (FLA) would have problems C/8 to C/12 is the normal rate with C/10 usually being ideal.

WWW

[Sunking]

One other note. Hope that's an AGM battery or it'll be short lived. 15.8 amps would put you slightly above a C/5 charge rate. An AGM should be able to handle that but a flooded lead acid (FLA) would have problems C/8 to C/12 is the normal rate with C/10 usually being ideal.

WWW

Yep minimum battery size for 380 watts using MPPT on 12 volts is 250 AH.

[clarko2000]

Couldnt have got things any more wrong!

Yep minimum battery size for 380 watts using MPPT on 12 volts is 250 AH.

Many thanks for sharing your knowledge guys. This was a project for a garage with no power. Looks like I need a bigger battery bank and a higher amped charge controller.
All very interesting and i will get it in the end!

[Sunking]

Many thanks for sharing your knowledge guys. This was a project for a garage with no power. Looks like I need a bigger battery bank and a higher amped charge controller.
All very interesting and i will get it in the end!

With 380 watts, and the high voltage panels you will have to have a MPPT controller of a minimum 30 amps with a Voc of at least 75 volts.

[clarko2000]

and for just one 190w panel?

With 380 watts, and the high voltage panels you will have to have a MPPT controller of a minimum 30 amps with a Voc of at least 75 volts.

Whats the minimum size battery and charge controller? Thanks

[Sunking]

Whats the minimum size battery and charge controller? Thanks

Depends on what kind of battery being FLA or AGM. For FLA minimum size is C/8 and largest is C/12 charge rates where C = Charge Amps, and X = Hours. A 380 watt panel at 12 volt battery can generate up to 30 amps. So for a FLA 30 amps x 8 hours = 240 AH. I will let you figure out C/12

For AGM the smallest you can safely go is C/4 and up to C/20 but not recommended to go that high with solar. So C/4 to C/12 range. 30 amps x 4 hours = 120 AH. Again you can figure C/12 for yourself.

[PNjunction]

Thanks for the quick reply Sunking! Im running a 12v 75ah battery. Look, Im new to all this so its a bit of trial and error at the moment. Sorry for not being clear, I DID buy 2 190w panles but I was only using ONE with the charge controller. I was only running 1 x 190w panel to the charge controller. But even that sounds like it is too much for the charge controller?
I did buy a 10amp MPPT charge controller. I thought that would be sufficient as the max amp of the panel is stated as being 3.47amp max. Surely that charge controller is fine for one panel??

If that is the 10A EPsolar/Tracer 1210RN, see the specifications near the front of the manual. Aside from just the current, you have to take into account the max rated PV POWER rating depending on your battery system voltage, which for a 12v system like you are running, it is limited by Tracer to only 130 watts. Yep, you are smoking the controller even with only one panel.

[clarko2000]

With 380 watts, and the high voltage panels you will have to have a MPPT controller of a minimum 30 amps with a Voc of at least 75 volts.

So if I got myself one of these batteries (190ah) linked to a 190w solar panel I would need a 15.8amp (20?) charge controller. I want to make sure this is right before I buy the battery. Thanks all.

http://www.ebay.co.uk/itm/251574876484?_trksid=p2055119.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT

Its just for an off grid garage set-up.

try not to complicate the answer for me, I'm still learning! Thanks

[Sunking]

So if I got myself one of these batteries (190ah) linked to a 190w solar panel I would need a 15.8amp (20?) charge controller.

That will work.