battery temp compensation

[Vic]

Hi fiddler,  sorry,    I should have typed out Charge Controller (CC).   Vic

[Resthome]

What do you mean by CC. Not familiar with that term.

CC= Charge Controller  ie Midnite Classic 150

[TomW]

What do you mean by CC. Not familiar with that term.

Charge Controller

[dbcollen]

And in case you missed it, CC is Charge Controller......   

[fiddlerkelly]

I am located in eastern canada in newfoundland. Where the volts are not far of 150 only approximately 14 away from max the winter with colder temp and reflection from snow may put it over the top of 150. The company selling me the the panels said I may be better off getting  a 200 midnite solar. The maximum length of wire from panels to to CC would be 45 feet. I am using #10 multi strand wire approximately 7 strands. So if I end up with all 150 watt panels 8 of them what would be the best configuration for connecting them to the midnite solar and which would I  be better off to use.

[vtmaps]

The company selling me the the panels said I may be better off getting  a 200 midnite solar. The maximum length of wire from panels to to CC would be 45 feet.
<snip>
So if I end up with all 150 watt panels 8 of them what would be the best configuration for connecting them to the midnite solar and which would I  be better off to use.

A classic 200 on a 12 volt system?  That's terrible advice.  You should not down convert such high voltages to 12 volts.  Especially since your array will be pushing the limits of a classic 150, and would exceed the limits of a classic 200.

You have not mentioned the Vmp or Imp of your panels, so I can't give you any meaningful advice on an array configuration.  You will certainly need a combiner and circuit breakers.

btw, In my opinion, your system is a disaster and you are about to compound it.  You have 9 battery strings in parallel, totaling over 2000 ah.   That is wrong for two reasons... 9 parallel strings is unworkable and a system that size should not be a 12 volt system.

Your proposed array (1200 watts) will be inadequate to properly charge a battery bank that size, although in reality there is no way, with any amount of power, to properly charge 9 parallel battery strings.  All you need is one shorted cell in one battery and you will have a fire or explosion.

My advice is to determine your loads and design an optimal system on paper.  Then, figure out how much of your existing system can be used to build a properly designed system.

--vtMaps

[zoneblue]

Vt is right, your are playing with fire without your firerproof gloves on.

If you want to install a system of the size you are comtemplating, you either need a professional, or you need to invest some time in learning electrical engineering. One of the two. Theres a reason people use sparkys to wire their houses, and solar is no different. In fact  with batterys, as vt said, off grid is actually more dangerous again.

As others have said it comes down to loads. You need a load budget. Take the below, and flesh it out so that each item has a number of Wh/day. Make sure everything is included, everything that you will need in your use case, for say the next 5-10 ten years. Thats about the life of the hardware.  See the links in the link in my sig for an example load budget.

Once you have then you can decide what is the best system voltage, and exactly how much battery, controller, and inverter you need. Do anything else and you just guessing, and burning money away.

I have mostly just lights at the  cottage 2 12 volt water pumps a 42 inch flat screen with basic receiver but plan on adding a 7 cut fridge with draws 1.5 amps and at times a laptop .Average draw on system will be approximately 4 amps /hour at most 8 hours a days little less in summer . Water pumps only run when needing water.

I heard so much about wiring batteries and got from it the less parallel is better.

[zoneblue]

One other thing, if you want to use dc pumps, then thats one reason to opt for 24V as opposed to 48V. But if your system is or will grow to  3kWp or greater then 48V is a must. For the PV, 45ft is nothing, and the Cl150 is your friend there.

[fiddlerkelly]

Just ordered another 2 panels with exact same spec as other 6 -150 watt panels that are coming.  So I will  now have 8 -150 watt panels total and from what I have been reading here should wire them up as 24 volt and that the midnite solar should do fine.

[fiddlerkelly]

Regarding the DC pumps how will 12 volt pumps work in a 24 volt system.

[zoneblue]

Re the pumps, 24v pumps are the same price as 12v pumps. 48v pumps dont exisit.

12v is a dead end for a growing system. You could theoretically run your exisiting 12v pumps off a dc converter, but i would not do it. Pumps need surge capability.

Like we were trying to convey, maybe try not to order anything else until youve got a plan
I suggest you head on over to the NAWs forum and get Bill and Coot to run over your design with you.

[fiddlerkelly]

Where do I find the NAWS forum. Thanks also for all advice , greatly appreciated.

[tecnodave]

Fiddler,

NAWS is Northern Arizona Wind and Sun.   On line store and great forum


Forum:     forum.solar-electric.com/forum.php

td

[fiddlerkelly]

Oh yeah I am member of the site just never use the abbreviation.  Thanks.

[fiddlerkelly]

Resthome

Just to get back to temp compensation. I checked all the cells in the batteries I took home, temps were between 79.5 -80.0 F.  the SP of all cells in the four 6 volt batteries were between 1.295 -1.30 before calculation. they all look good to me . what do you think.  So with these readings does that mean there should be no sulfation in those batteries at present.

fiddlerkelly