Advice needed on my Solar setup - It's a mobile setup for camping or just using at home if i'm not camping.

[Napalm]

I've been buying a few items and kinda been planning from what i read on various sites.

I have 2x 180Watt 72cell Solar panels - Optimum Operating Voltage (Vmp) 36.8V;Optimum Operating Current (Imp) 4.892A; Open-Circuit Voltage (Voc) 45.76V

I'll be linking them together in series. So i'm guessing it will push 75volts to 80volts maximum. I have an EPsolar 20A controller that i purchased the previous month, it's rated upto 100v input. Then i have 2x 12V 105ah Deep cycle battery's that i've kept charged every few weeks. <the 2x battery's will be running in 12v. as my inverter is a Pure Sine Wave 600w 12v DC to 230v AC>

This solar setup is made to be mobile. not roof mounted or fixed location, i'll place it in a sunny area (In South Africa, we get alot of sun)

1. Is my Controller maybe not big enough? The 2 panel input volts will be 70-80volt but less amps. Will it charge my battery to maximum of mppt power of 20amp?
2. Is 20amps enough for the 2x 105ah. I won't be running alot of power on it, maybe around 80-150watt for few hours at a time.
3. Is my panels not too much 360watts combined to charge a 12v setup of 2x 105ah? (so it will run as if it's 12v 210ah setup basically)
4. Due to it being a mobile setup, how do i ground it? Do i just take a negative wire and plonk a spike into the ground or does a mobile setup like mine not need grounding or to be earthed?
5. With my panels producing around 300watts of power & my utilization during the day not being more than 100-150watt. Can i run items during the day on "free power" Meaning. it will run my equipment and charge my battery's a little. <- In the case where my battery's is already full. Because my draw is only 100-150watt by my panels is charging panels @ 300w or more.

I've hinged the 2 panels together (to be suite-case style, to carry easily and put into the boot when traveling. (1250mm x 992m per panel). When camping i normally would use one 12v battery.

Any advice is welcomed.

In a nutshell this is how the setup will be linked :


2 Solar panels are hinged together like this - just as illustrated (except mine doesn't have the slide out stands etc. I still have to figure that out) :

 

[mikefitz]

Will it charge my battery to maximum of mppt power of 20amp?

Yes, with 360 watts of solar, in theory that could be converted to over 20 amps in a 12v system. The MPPT will limit to 20 amps.

Is 20amps enough for the 2x 105ah.

Yes, generally charge LA at between 0.1 and 0.2 of capacity.

Is my panels not too much 360watts

You will rarely get full power from the panels, the controller will limit the output to 20A.

mobile setup, how do i ground it?

Not needed .

Can i run items during the day on "free power"

Yes

this is how the setup will be linked

Do not connect the inverter to the load outputs, connect direct to the battery. The inverter could take well over 50 amps, the load outputs of the controller are limited to the 20 amp rating and are not designed for inverter loads.
230v ac needs care so ensure items connected are ideally dual insulated and all leads and equipment is in good condition.

Mike

 

[Napalm]

Yes, with 360 watts of solar, in theory that could be converted to over 20 amps in a 12v system. The MPPT will limit to 20 amps.

Yes, generally charge LA at between 0.1 and 0.2 of capacity.

You will rarely get full power from the panels, the controller will limit the output to 20A.

Not needed .

Yes

Do not connect the inverter to the load outputs, connect direct to the battery. The inverter could take well over 50 amps, the load outputs of the controller are limited to the 20 amp rating and are not designed for inverter loads.
230v ac needs care so ensure items connected are ideally dual insulated and all leads and equipment is in good condition.

Mike

Thanks for the feedback.

yeah i think my downfall is my inverter. I wanted to get a pure sine wave but the one's i could find local was only 12v in the low wattage range. As i don't need a 2000watt Pure sine wave. My draw on power is minimal. maybe 100watt to 150watt (my TV, few lights etc).

So i think my solar panels is overpowered... for what my battery setup is (as i'm limited to 12v). I have 2x 105ah Battery's in 12 Parallel. My MPPT is only 20amps (so it can only charge at 20amps maximum..) Maybe i should have gone with 30amp.. But then again i'm not sure if it's good idea to push so much amps to 12V battery's. In 24v setup it would push less amps because the voltage is higher.

Strange enough the Manual for my MPPT states max panel size could be 390watt for 12V. (EPsolar Tracer2210AN. So i'm guessing they factor in the losses etc in already). Or can my setup push more than the 260watt stated in manual when boosting? (i wonder)


Anyway, So my battery setup must be 12v , My Solar panels are 2x 180W (but obviously one never gets full potential. So i would say i would have gotten 140w or maybe 145w out of each panel with MPPT. Combined maybe around around 290watts.

So having the 20amp MPPT also limits me now.. as on 12v it will charge at 13.8v 99% of the time right, or is that the float? Even at float 13.8x20amps is around 276watts. I'm not sure if 20amp MPPT can do full 20amps for long periods so i'm guessing it will not charge at 20amp for long periods. So maybe around 255-260watts is what i'll be getting.

With my drawbacks of MPPT being 20amp and battery setup kinda being forced on 12v (due to inverter) - I'm losing out on about 30watts of power that i will never see. Due to this config.

I have heard of boosting voltage , i'm not sure if the volt charge boost will happen if inverter is working and have a big load on it during the day maybe. Will it go above the 13.8v to around 14.4 when there is load on it? 14.4 would then give around 14.4x20amp = 288watts (which is very near what my panels are meant to put out.. i guess (unless i'm missing something)

 

[12VoltInstalls]

Did you search out a pure sine wave inverter? That’s your only limitation imho- killing the TV or whatever.