1kw 24v off grid system questions.

[Obtuse.Lumen]

Hello solar panel talk. Forgive me for joining the forum to ask these questions.

What I have purchased so far is:
24v 1400 watts in solar panels
outback flex max 60a
two 12 batteries(don't plan on using then too much)

I want to have two inverters, 1 at 1500w 24v and 1 at 300-600w 12v

Is it safe to use a regulator lower voltage from the charge controller/battery bank? Or will I have to go with a 24v 300- 600w inverter?

[Logan5]

No, you will need to replace the 12v inverter.

[PNPmacnab]

There are balancers they sell that allow you to use a 12V tap with a 24V battery system. A little pricey at about the same cost as buying another 24V inverter. I assume they are just a buck converter that sets its target voltage at half the 24V reading so the batteries will balance in a charge. Not practical unless you have a lot invested in 12V equipment.

[inetdog]

There are balancers they sell that allow you to use a 12V tap with a 24V battery system. A little pricey at about the same cost as buying another 24V inverter. I assume they are just a buck converter that sets its target voltage at half the 24V reading so the batteries will balance in a charge. Not practical unless you have a lot invested in 12V equipment.

Actually, the ones that I have seen use "current mirror" circuitry to ensure that the balancer draws equal current from both the upper and lower batteries when it is supplying a 12V load. Those do not care particularly what the exact center point voltage is, and will not work properly if the upper and lower batteries are not equal in capacity.

You have to be a little careful about the terminology used in this situation.
For Lithium batteries a "balancer" would be part of a battery management system and would act primarily to ensure that cell voltages were approximately equal as a result of the charging process.
Within reason identical Lead Acid batteries in a series circuit are self balancing during charging as long as you bring them to a full charge.

What we are discussing here is instead a device, which could be a balancer or could be just a DC to DC converter, that allows use of a 12V load with a 24V battery bank.

[PNjunction]

And just to make sure, when you state you won't be using your 12v batteries much (I'm assuming wired for a 24v series string), you aren't thinking of directly attaching the panels / controller to the inverters right?

Some people assume that they can do without or bypass the batteries and drive them directly from the charge controller. Uh, no go.

[Wy_White_Wolf]

1400 watts of panels into 2 - 75 to 100aH batteries. That's going to get interesting. Hope you catch the fire before it burns the place down.

WWW

[PNPmacnab]

The unit I was referring to, google EQ 12/24-20 since they don't seem to like links here.

[Sunking]

Can you say great balls of fire? 1400 watts into a 24 volt 150 amp battery? That is nucking futs. Minimum requirement to keep it from blowing up in your face is 450 AH battery.

[PNPmacnab]

That may be true for most. I have 1500W going into a single car battery. I need that much to run things real time, even in rainy weather. Of course, the charge controller is limited to 14A.

[Sunking]

That may be true for most. I have 1500W going into a single car battery. I need that much to run things real time, even in rainy weather. Of course, the charge controller is limited to 14A.

You are a FOOL.

[PNPmacnab]

Are you really an engineer? Threatened because you don't have any ideas of your own? I have a very efficient system I live with off grid for 5 months a year powering fridge, pump, lamps etc. Even a CPAP machine. Excess power goes to make hot water. No electrons are wasted unlike most of these big dumb systems. Totally designed for purpose. And I hate batteries. The one I use is out of a vehicle I don't bring with me. It saves that battery from sulfating.

[Sunking]

Are you really an engineer? Threatened because you don't have any ideas of your own? I have a very efficient system I live with off grid for 5 months a year powering fridge, pump, lamps etc. Even a CPAP machine. Excess power goes to make hot water. No electrons are wasted unlike most of these big dumb systems. Totally designed for purpose. And I hate batteries. The one I use is out of a vehicle I don't bring with me. It saves that battery from sulfating.

You already proved you do not know what you are doing. 1500 watts to a car battery with 14 amp controller. They should have banned you instantly for making such a foolish and dangerous statement. Now get lost before you get someone hurt and get sued for gross negligence.

I bet you have no clue you turned your 1500 watt panel into a 200 watt panel. Only a FOOL would do that.

[Mike90250]

Sunking - he does it for the cloudy days, so he still gets some harvest. Generally, that much overpaneling IS dangerous, but if he's set a current limit on the controller, it should be OK