About to buy new Batteries - not sure if my set up is correct to start with

[obba]

Hi Cariboocoot,

Great advice there.

I didn't think about having to charge/boost it with a 24v charger - incorporated with the invertor.
Will check some out today if i get time.

Those premade buggy cables look good for equalising, but i wont buy anything unitl i get the system up and running.

I'll do some hunting for a invertor / booster.

Cheers,
Alan.

[Cariboocoot]

It occurs to me we may be talking at cross purposes here.

"Equalization" is a charging process where battery Voltage is raised above normal to bring the specific gravity of cells in line with one another; equal. Wire gauge does not matter here; if it's large enough to handle the high current of the Bulk stage it will be fine for the rest.

I think you may be thinking of the benefit of pre-made cables of the same length being used to connect batteries so that the current is shared equally between two (or more) parallel connections. In this case it is essential that all parallel cables be the same gauge and length; equal.

I hope that clears that up.

[obba]

It occurs to me we may be talking at cross purposes here.

"Equalization" is a charging process where battery Voltage is raised above normal to bring the specific gravity of cells in line with one another; equal. Wire gauge does not matter here; if it's large enough to handle the high current of the Bulk stage it will be fine for the rest.

Yeah that's ok. I understand the difference. That little much i know....

I think you may be thinking of the benefit of pre-made cables of the same length being used to connect batteries so that the current is shared equally between two (or more) parallel connections. In this case it is essential that all parallel cables be the same gauge and length; equal.

I hope that clears that up.

I was thinking of using my existing 'thick' cables and using those others to 'equalise' the 'rest'.


As for the Controller and Charger with some of the brands you have mentioned is now a big problem with the price. There isn't any way we can afford those sorts of prices. Of course i am guilty - as the question of the guy bying a Rolls Royce: If you have to ask how much,, etc.

Just thinking about the 12v to 24v conversion and how the panels are wired up on the roof. Will do anotherbasic diagram as to what i mean...

Have a good night guys..

Cheers.
Alan.

[westbranch]

there is another way to supply your 12 v loads, if they are low enough, and that is to get a reasonably priced 12V pwm charge controller and have it charge 1 -12 v battery, that may keep SWMBO happy in the switch over to all 24v...

[obba]

Hi all,
Been away for a bit. And we have saved some money to go ahead with the 24volt setup.

I have ordered 8 T105's RE's.

And i just wanted to know how i have to change the cabling system to get 24v into the PL60 regulator.

This is the roof setup:
http://i202.photobucket.com/albums/a...ps207a3b65.jpg

There are 5 panels (in a bank), and wired to be give out 12v.
There are 4 banks (sending 4 feeds of 12volts to the regulator).
There is approx a 4-6mtr run to the edge of the roof. And then a further 7-8mtr run to the Regulator. These runs are one continuous cable.

So a real stupid question, but i have to ask:
As a bank of panels is giving out 12v, is it ok to make two (out of the four feeds), to join two of them in series (giving 24volts) at the input of the bus bars?

So in effect i will make the 4 feeds join into two 24v feeds at the bus bars [Nice easy way as to not have change any cabling across the roof].

Or this will negate the 24v (less cable thickness advantage), run from the solar banks?

If so, what about (at the 4-6mtr), joining the 4 x 12volt banks into 2 feeds of 24v at the roof level [Will require a cable box enclosure] and then the remaining 7-8mtr run is all 24volts...?


Thanks...

[westbranch]

the simplest way to describe this is to hook the negative of panel #1 to the positive of panel 2 and the pos of panel 1 and the neg of anel 2 to the buss bar. Hope this makes sense. try drawing it out.
In this way the voltage will be 12 + 12 = 24 from 2 panels.

hth

[Cariboocoot]

You are now going with a 24 Volt system, correct?
You will need an array capable of at least 35 Vmp. Having the panels wired as 12 Volts won't even nudge the battery, much less charge it.

Normally you get panels and they have polarized MC4 connectors on them. Plug two together and you get a series string of two panels that produces 24 Volts nominal.
Put four in series by this manner and you get a nominal 48 Volt string. Parallel five such strings together and feed it to an MPPT type charge controller. There's your twenty panels used. The output will be fine for charging a 24 Volt system.

And did anyone mention the need for fuses/breakers on each string?

[obba]

the simplest way to describe this is to hook the negative of panel #1 to the positive of panel 2 and the pos of panel 1 and the neg of anel 2 to the buss bar. Hope this makes sense. try drawing it out.
In this way the voltage will be 12 + 12 = 24 from 2 panels.

hth

Thank you for that advise! Very simple and i get it straight away.

Cheers,
Alan.

[obba]

You are now going with a 24 Volt system, correct?
You will need an array capable of at least 35 Vmp. Having the panels wired as 12 Volts won't even nudge the battery, much less charge it.

* Hi Cariboocoot (glad to see your still here), yes starting to go 24v.

* With this "array capable of 35vmp and the panesl wired as 12volts.." What is this 35vmp?


Normally you get panels and they have polarized MC4 connectors on them. Plug two together and you get a series string of two panels that produces 24 Volts nominal.
Put four in series by this manner and you get a nominal 48 Volt string. Parallel five such strings together and feed it to an MPPT type charge controller. There's your twenty panels used. The output will be fine for charging a 24 Volt system.

* The 'big panels' i have are 5 a piece, not 5 'big panels' by 4 individual solar panels...
* We don't have the money to buy a MPPT type charge controller. I have read about the MPPT controllers and whilst they can 'distribute' the panel(s), * maximum input to the batteries etc, it IMO and in our case, is not cost effective.

And did anyone mention the need for fuses/breakers on each string?

* Yes, i will be looking at that. At the moment, I have a fuse/breaker on the input - after the bus bars - to the PL60 and then the same after the PL60.
* So i will once i get the wiring to 24volts, have a fuse/breaker on the 'new' two feeds.

[Cariboocoot]

* Yes, i will be looking at that. At the moment, I have a fuse/breaker on the input - after the bus bars - to the PL60 and then the same after the PL60.
* So i will once i get the wiring to 24volts, have a fuse/breaker on the 'new' two feeds.

Two feeds? According to my calculations you will have five feeds to the combiner and that means five fuses or breakers; one on each string.
You must not combine strings and then connect to circuit protection. It will not be safe for the reasons we use circuit protection there.