Charge Controller Amps

[happyVanderer]

How many amps should my charge controller have when combined with 500 watts of solar and a 2000 watt inverter? Thanks!

 

[highdesertranger]

not enough info,

what controller? MPPT or PWM?
how many volts into the controller?
are the panels in serial or parallel?
batteries, type and amp hours?

highdesertranger

 

[wayne49]

How many amps output depends on how much direct solar radiation is reaching your panels.

 

[MotorVation]

I have 590 watts of solar on the roof and a 45 amp MPPT charge controller. A couple weeks ago I was watching the remote meter and it was pulling in all 45 amps and somewhere around 620 watts. When it reached 46 amps it cut the power back to 45 like it's supposed to. I've only seen that once and it happened between clouds at a higher elevation

 

[happyVanderer]

It's an MPPT. I was told by the inverter manufacturer that my charge controller may be too small for my system. However, after reading the comments, I am back to the conclusion that the problem is the inverter.

 

[Dakotalee]

For mppt controller
Watts ÷ lowest voltage ( battery bank) = amps. Round up.
Guessing you have a 12v system
500÷12= 41. Go with. A 50a controller

 

[Dakotalee]

You could do 40 a just better to round up so you get all the solar and can expand. You'll never see the full 41.

I have 1125 watts and a 24v system. I have a 40a controller that can be over paneled.

 

[MotorVation]

What's your battery setup? That inverter may be pulling more amps than the batteries are able to put out

 

[Dakotalee]

That inverter don't pull much by itself. Usually an amp or less. Its the loads on the inverter.

What exactly is the problem you are having?

 

[MotorVation]

That inverter don't pull much by itself. Usually an amp or less. Its the loads on the inverter.

What exactly is the problem you are having?

Captain obvious to the rescue    :dodgy:

 

[happyVanderer]

I am able to charge things with my 2000 watt inverter such as cell phone, computer, etc. The problem is that I can't run my 700 watt microwave, my 700 watt blow dryer, or my 600 watt flat iron. Anything that has an initial surge ( the inverter is 3000 watts for surges). I'm stumped. I don't mind getting a new inverter, I just want to use my three appliances.

 

[jonyjoe303]

where do you have your inverter hooked up to? to the battery or to the load out of controller? The inverter has to have very thick gauge wire and connected directly to the battery to handle 2000 watts. Also some devices require a pure sine inverter to work, check if your inverter is pure or modified sine.

 

[happyVanderer]

Thank you for trying to help me find the problem. The inverter is hooked up correctly with the correct wire and it is pure sine wave.

 

[Trebor English]

Diagnosis will require more information.  The 600 watt flat iron is just resistive so there is no surge.  First connect a volt meter to the 12 volt input to the inverter.  Write down the voltage.  Turn on the inverter and write down the voltage.  Plug in and turn on the flat iron while watching the meter.  The 12 volt voltage should drop.  If it goes low enough the inverter will shut off and then the voltage will rebound.  It may stay low for a while.  Write down the lowest voltage observed.  

If the input to the inverter drops it could be the battery or the wire.  Repeat the test measuring at the battery.  If the battery voltage drops the same as the inverter input then the problem is likely the battery.  If the battery voltage stays substantially higher than the inverter input voltage the wire is suspect. 

If the 12 volts into the inverter doesn't drop below 11.5 volts look at the inverter itself.  Connect the voltmeter to one 120 volt socket with the iron plugged in to another.  With the iron off and the inverter on you should get 120 volts.  Turning on the iron should cause the inverter to drop but it shouldn't drop more than 10 volts.  If it drops more than that with more than 12 volts dc input the problem is likely in the inverter.   

As you use the iron for testing it may get hot enough for the thermostat to turn it off.  That makes the iron not a good test.  Switch to the hair blower.  Does the hair blower have two heat settings?  The lower setting might be good for testing.

 

[abnorm]

Hi Julie...….Sorry you're having problems......You came to YARC camp this Winter to "borrow" some power to install your stuff.....

Let me add a little context...I helped you install the Solar out-in-the-desert....we used what you had with you in a limited timeframe

We mounted the used solar panels directly thru the Hi Roof with nuts and bolts...….the sheet metal is so thin on the new Ford's

I remember we had to "beg/borrow" a pair of MC-4's to hook up the too-short existing wires on the used SanTan panels

Parallel wired panels with #10 AWG thru a gland to a disconnect switch...…….and then on to an EPever controller

again #10 from the controller directly to the "batteries"...…..I think they were 2-6 volt (type ?) wired in series with a heavy (#2 ?) jumper

The HUGE (brand?) inverter was mounted under the bed and fed with the supplied short heavy wire directly to the batteries

The Blue Seas fuse block connects to the same common points on the batteries with #10 wire

Here's the only picture:





There were NO Buss bars or main fuses......No supplies and No budget

You were going to wire the lighting circuits to the Blue Seas fuse block.....multiple #12 runs in black loom seen hanging off the bed

………..as well as the chest fridge that sits atop the batteries...….in a custom scrap-wood box


Looking back from 2,000 miles away...……….. I don't think you have enough BATTERY to drive that Inverter

 

[Dakotalee]

I'm thinking theres not enough battery power also

 

[jimindenver]

2 6 volt batteries will have resistance issues powering a larger load.