MorningStar TriStar 45 MPPT Solar circuit Breakers & fuses

Re: 10 year temp lows

Nic,

lionheartlakes wrote: »

Thanks for all your helpful information, i have checked the 10 year weather lows in my local area and the average seems to be -2,...

See if you can find the record lows--average lows are not good enough.

...i will purchase either 9 or 10amp circuit breakers double pole protection.
I hope that i dont have any weather extremes temps in the future - 10 plus.

You will not need any circuit breakers in series with each solar array string if you have two or one parallel connected strings (only three or more string need a series fuse/breaker).

I have one more question for u guys;
my exsiting system consist of
3 x solar swiss 24v 150watt panels
15 AMP SOLAR PANEL CHARGE CONTROLLER (controlling one panel)
20 AMP SOLAR PANEL CHARGE CONTROLLER (conttrolling 2 panels)

Depending on your battery bank and solar panel configurations--you may need MPPT controllers only--or you may get away with a less expensive PWM controller (one panel and a 24 volt battery bank).
my battery bank is GNB absolyte 2v 1600 amp

http://cgi.ebay.co.uk/12-VOLT-1600-AMP-HOUR-INDUSTRY-BATTERY-PACK-solar-panel_W0QQitemZ220551249943QQcmdZViewItemQQptZUK_ConsumerElectronics_Batteries_SM?hash=item3359e10017

Will your bank be 24 volt or 12 volt? How many batteries in parallel/series/etc...

With large batteries, you should have a relatively large charge controller (solar or AC mains type). For storage, you can use a 1% rate of charge. For active cycling (used with daily loads), you should be in the 5% to 13% of 20 Hour capacity. For example, 1 battery and 12 volt bank:

• 1,500 AH * 0.01 = 15 amps minimum
• 1,500 AH * 0.05 = 75 amps minimum for cycling load
• 1,500 AH * 0.13 = 195 amps recommended maximum

(note: your AGM's can probably take even more charging current--but probably not a practical option for you anyway).

Your three panels with MPPT charge controllers and 12 volt output would be:

• 3*175 watt * 0.95 MPPT eff * 1/14.4 volts = 34 amps your controller
• 1,500 AH * 0.05 min charge * 14.4 volts * 1/0.95= 1,158 watt solar array recommended minimum

Unless your loads are very load and/or you have generator/electrical mains for AC charging--you should be looking at more solar panels and solar charge controllers anyway.

AGM batteries are a very good battery but are senstive to over charging (probably will not be your problem, but make sure you charge controller is set for AGM/sealed battery--no equalization; and your charging voltage is appropriate for your bank).

For your system, you will run a real chance of "deficit charging"--basically, you will probably take more energy from the bank than the solar panels can replace. I don't know how your AGM battery responds to long term operation below 75% or 50% state of charge--but most batteries will "sulfate" and loose capacity over over a few months and by the end of a year--will probably need replacing.

Read these battery FAQ's for background on care and feeding of your battery bank:

Deep Cycle Battery FAQ
www.batteryfaq.org

Normally, you would measure specific gravity to check the state of charge. You are left with measuring the battery bank's resting voltage to estimate state of charge--3 hours or so of no charging/discharging current.

Have you looked at a Battery Monitor for your system. I believe they are really helpful for any battery bank type--but almost mandatory for AGM to estimate the state of charge at any time. Here are some suggestions for Battery Monitors that may be local to you:

stephendv wrote: »

With regards to battery monitors available in Europe, you can find products from:
- Victron energy
- Smartgauge.co.uk
- www.studer-inno.com
- and Xantrex

My question is can i connect the steca controllers and ms controller to the batteries, if so which is the best way to do it?

Make the charge controller common connections right at the battery bank/bus bar common points. That will give each controller the most accurate battery bank voltage for proper charging. Follow the manuals for recommended battery cable diameter (and keep lengths as short as practicable).

Steca and Morning Star both make MPPT and PWM type controllers (I think)... You have to make sure your panel voltage/current matches battery bank voltage for the correct type of controller.

PWM controllers (for optimum power transfer) need the Vmp to be around Vbatt-charging + 2 volts minimum.

With your panels, one panel + 24 volt bank can operate with a (cheaper) PWM controller (or two panels + 48 volt bank is OK too).

Otherwise, any 12 volt bank and your solar panels should have an MPPT type charge controller. You can read about charge controller types in these FAQ's:

All About Charge Controllers
Read this page about power tracking controllers

The guy who sold me the equipment said it was ok but i have more confidence in your opinion.

Thank you for the compliments--we all try here.

However, make sure you understand your application--there is only so much we can guess at from behind a keyboard and screen.

If you have questions, or something does not make sense--please ask. A 1,500 AH battery is a scary thing... Much worse than working with house hold mains power.

A 1,500 AH 12 volt battery can output more than 10,000 amps into a dead short. Make sure that all wires/cables going into or out of (typically the positive Bus connection) are protected by appropriately rated DC fuses or circuit breakers.

Wrapping tools with electrical tape, removing any jewelry, wearing safety glasses, etc. ... for working with a lead acid battery.

-Bill