The beginning of our 5th wheel solar build.

[lifeontheroad]

These are my 4 Trina solar panels.
280w top
255w bottom
In series parallel


40amp renogy charge controller set at 24v (will be going back to 12v soon and getting another controller)

4 interstate Deep cycle RV batteries (81AH BUT FEELS LIKE LESS) can't wait to upgrade

 

[MisterSandals]

280w top
255w bottom
In series parallel

Are the amps and volts close enough to connect them as you have them? Presumably 2S the top and 2S bottom?

When combined in parallel, add the amps, clip the higher volts to match the lower. If you post Vmp and Imp of panels, someone can easily determine the optimal 2S2P config of your array.

1070W / 28V charging = 38A

Are you thinking your 40A SCC is not enough?

 

[lifeontheroad]

Are the amps and volts close enough to connect them as you have them? Presumably 2S the top and 2S bottom?

When combined in parallel, add the amps, clip the higher volts to match the lower. If you post Vmp and Imp of panels, someone can easily determine the optimal 2S2P config of your array.

1070W / 28V charging = 38A

Are you thinking your 40A SCC is not enough?

Yeah they're about 30 and 31 volts and Amps are within less than half and amp. If I go back to 12v I'll need two SCC to handle all four panels. If I had a 24v inverter I'd keep as is but I have a better deal on 12v right now

 

[MisterSandals]

How many watts will you be pulling from 12V battery bank?
If your inverter will be over 2000W, i'd be mighty tempted to go 24V to keep the amps reasonable (the wiring and fusing gets expensive and the added cost of a 24V inverter may actually be negligible).

3000W inverter / .85 efficiency / 10V inverter cutoff = 353A

500A fuses, switches and wiring ain't cheap. I'd price these out to get a better idea as to which system is cheaper to build.

Looks and sounds like you know what you're doing so you're probably way ahead of all this. Good luck!

81AH BUT FEELS LIKE LESS

Lead acid is only 50% dischargeable so you only have 160Ah (with 4x batteries) of usable battery.
A single 200Ah LiFePO4 would be a 25% increase (and 50% weight reduction, some of that is your wallet getting lighter).
But with lithium you'd have to account for your inverter amp draw and over 200A gets mighty tough.

Sorry for rambling...

 

[lifeontheroad]

How many watts will you be pulling from 12V battery bank?
If your inverter will be over 2000W, i'd be mighty tempted to go 24V to keep the amps reasonable (the wiring and fusing gets expensive and the added cost of a 24V inverter may actually be negligible).

3000W inverter / .85 efficiency / 10V inverter cutoff = 353A

500A fuses, switches and wiring ain't cheap. I'd price these out to get a better idea as to which system is cheaper to build.

Looks and sounds like you know what you're doing so you're probably way ahead of all this. Good luck!

Lead acid is only 50% dischargeable so you only have 160Ah (with 4x batteries) of usable battery.
A single 200Ah LiFePO4 would be a 25% increase (and 50% weight reduction, some of that is your wallet getting lighter).
But with lithium you'd have to account for your inverter amp draw and over 200A gets mighty tough.

Sorry for rambling...

I have a few coupons that'll that make the 12v inverter in aiming for cheaper. Also we don't draw much. It's just the fridge, TV, portable devices and a few kitchen items like a Waffle maker. Those are all still under 1200w. We don't use the AC or microwave. So there isn't any that draws that much current.

I rather would save that extra for lithium batteries. I plan on getting 3 or 4 200ah batteries when the time comes

Depending on the prices of things around time if purchase I may stay with 24v. So far it's not too bad.

 

[lifeontheroad]

How many watts will you be pulling from 12V battery bank?
If your inverter will be over 2000W, i'd be mighty tempted to go 24V to keep the amps reasonable (the wiring and fusing gets expensive and the added cost of a 24V inverter may actually be negligible).

3000W inverter / .85 efficiency / 10V inverter cutoff = 353A

500A fuses, switches and wiring ain't cheap. I'd price these out to get a better idea as to which system is cheaper to build.

Looks and sounds like you know what you're doing so you're probably way ahead of all this. Good luck!

Lead acid is only 50% dischargeable so you only have 160Ah (with 4x batteries) of usable battery.
A single 200Ah LiFePO4 would be a 25% increase (and 50% weight reduction, some of that is your wallet getting lighter).
But with lithium you'd have to account for your inverter amp draw and over 200A gets mighty tough.

Sorry for rambling...

I was looking at getting a renogy 12v 3k inverter with a big discount or sungold power 24v 3k. Not that we'll need all 3000 watts but I'm sure we can get up to the 1900-2100 point at Max.

Still trying to decide between efficiency and price

 

[MisterSandals]

If you're looking at 3000W inverters, 12V is out of the question. Lots of people have been down that costly road and back.