Help needed ..head spinning

[Agentblue]

First post be gentle.
Thanks for the add.

Now to pick your brains.

Mate gave me a 20a PWM controller .(brand new)
I have the chance to purchase either 250w panels

100 brand new mono specs 30v vmp and imp 8.33a. (assume this is a grid tied panel) or 85w panel 40 pounds, used poly 18v vmp imp 4.7a

My head is spinning .
I want it to power 3 led strip lights , a small 12v cig lighter , security led light and at a later stage an inverter to power a running machine in my garage. Not interested in running an electric cable to garage as I want to go solar. Have enough room to fit two 250w panels without mounting on roof which will get sunlight for approx 6 hrs a day without shade.
Either I purchase one 250w mono or 2 85w poly??
do I need more than one 12v 120ah deep cycle battery .

To be clear I want to be able to add to system when I add running machine to garage at later stage but not essential if total cost of solar exceeds 500 pounds.
Thanks for help in advance 👍

[Sunking]

You cannot use the 30 volt panels on a 12 volt system with a PWM charger. Must use a MPPT charger.

Have a nice day.

[Agentblue]

You cannot use the 30 volt panels on a 12 volt system with a PWM charger. Must use a MPPT charger.

Have a nice day.

So my option is 2x85w panels with pwm ...or 250w with mppt charger ?

Am I right in saying the 2x 85w will give me 9amps?
What size deep cycle battery will I need ? To give the battery a decent charge over 1 to 2days ? And will it be sufficient to run the lights and 12v socket ?

Sorry for all the questions .

[Mike90250]

> 85w panel 40 pounds, used poly 18v vmp imp 4.7a

2 of those 85w panels in parallel will get you in real life, about 7 amps. Just like the 37mpg car gives you 29mpg

That would run a couple small lights, but not much of an inverter . sorry

[QuantumSlice]

I have done a couple of 12v projects.

First project was a solar charge for my 40 foot boat batteries. MPPT charge controller is what I used. Very cheap, very good. 100 W solar panel into the MPPT controller. Works great. Even had a second DC circuit it would support. Get your equation going: Power = current * voltage. Size the MPPT appropriately, they had specs on it that i compared to what i was trying to do.

The second time I got into 12v project - my cargo van conversion - i simply got a Yeti400 Lithium and Yeti compatible solar panel. These are fun devices that simplify everything. Gives you an independent amperage display of charge and usage. Didn't have to think about it.