inverter question

[Mike90250]

Read this article about batteries in parallel. More than 2, and complications start to build up.

http://www.smartgauge.co.uk/batt_con.html

(hmmm. their site is quite slow tonight)

[mark2310]

Moved to the off-grid area


First, you need a 24V inverter to run off of a 24V battery bank. A 12V inverter will die very quickly

Your MPPT controller should be able to convert your panel voltage to 12V with little loss, if it IS a true MPPT.

A 1,000 watt inverter will only run at full power off a single 12V battery. It's idle power will be about 100w just sitting there. That's a lot of inverter, and I suspect you will do much better to use a smaller inverter sized to your loads

Loads - what are you consuming ? That will set the size of the battery bank, and that sets the voltage and amperage of the whole system. The panels you have will only support 500w of daytime loads, so a larger inverter would be wasted.

Hi

Thanks again for the info.
Is it not possible to use the inverter with more batteries wired in parallel?

My use for the set up will be to run my caravan and I intend to build the system to be mobile on a small trailer so all items will have a sort cable run except for the connection to the van. This will be from the inverter to the van 240v AC.

I hope what im trying to say makes sense.

Thanks
Mark

[Mike90250]

Moved to the off-grid area

At the moment the system im building has 2X 235watt panels at 37v each.
A 40 amp MPPT.
One 110 ah 12v battery.
A 12v 1000w inverter.
I know I will need more batteries.
Is it possible to run a 12v inverter from a 24v system. (I think it will be 24volt because of the panel input)
or is it possible to charge a 12v battery from the panels that I have.

First, you need a 24V inverter to run off of a 24V battery bank. A 12V inverter will die very quickly

Your MPPT controller should be able to convert your panel voltage to 12V with little loss, if it IS a true MPPT.

A 1,000 watt inverter will only run at full power off a single 12V battery. It's idle power will be about 100w just sitting there. That's a lot of inverter, and I suspect you will do much better to use a smaller inverter sized to your loads

Loads - what are you consuming ? That will set the size of the battery bank, and that sets the voltage and amperage of the whole system. The panels you have will only support 500w of daytime loads, so a larger inverter would be wasted.

[mark2310]

It is not possible to run a 12V inverter from a 12V battery bank.
It is possible to charge a 12V battery from a 37V panel, or two 37V panels in series. That is the job that the MPPT inverter is made for.
As a practical matter, which you should have looked at before buying the 1000W inverter, 1000W is too large to drive comfortably from a 12V battery. The DC wiring is large and sensitive to bad connections at that amperage (around 100A.)
You can keep the panels and the CC and go to four six volt batteries in series to make a 24V 200AH system. But you will have to change the inverter.

Thanks for the info.
So it is possible to charge a 12volt battery from the 2 37volt panels I have through the MPPT.
So can I increase the number batteries to power the inverter then at a later date change it to a 24v set up?

Thanks again
Mark

[inetdog]

Hi

I need help with a problem.
At the moment the system im building has 2X 235watt panels at 37v each.
A 40 amp MPPT.
One 110 ah 12v battery.
A 12v 1000w inverter.

I know I will need more batteries.
Is it possible to run a 12v inverter from a 24v system. (I think it will be 24volt because of the panel input)
or is it possible to charge a 12v battery from the panels that I have.

Thanks
Mark

It is not possible to run a 12V inverter from a 12V battery bank.
It is possible to charge a 12V battery from a 37V panel, or two 37V panels in series. That is the job that the MPPT inverter is made for.
As a practical matter, which you should have looked at before buying the 1000W inverter, 1000W is too large to drive comfortably from a 12V battery. The DC wiring is large and sensitive to bad connections at that amperage (around 100A.)
You can keep the panels and the CC and go to four six volt batteries in series to make a 24V 200AH system. But you will have to change the inverter.

[foo1bar]

I think you have this in the wrong section.
I'd suggest asking a mod to move this thread to the "off-grid" section.
(and the mods can feel free to delete my post if they do move it)

[mark2310]

Hi

I need help with a problem.
At the moment the system im building has 2X 235watt panels at 37v each.
A 40 amp MPPT.
One 110 ah 12v battery.
A 12v 1000w inverter.

I know I will need more batteries.
Is it possible to run a 12v inverter from a 24v system. (I think it will be 24volt because of the panel input)
or is it possible to charge a 12v battery from the panels that I have.

Thanks
Mark