Need advice on proposed wiring using Busbars

[SunEagle]

Sorry I missed that: Just rechecked the battery specs. 225ah, So 1800ah total

Panels:
100 watt
Voc: 21.6
Isc: 6.32
Vpm: 17.4
Imp: 5.75

To get that 1800Ah rating you would have to wire all 8 batteries in parallel for a 6volt 1800Ah system.

You add battery voltage when you wire them in series and their Ah rating when you wire them in parallel.

So again if you use those 8 x 6v 225Ah batteries wired for a 12volt system you get 4 sets of 2 for a total of 900Ah 12volt system.

To properly charge that system you need 90Amps. So that Xantrex 40A CC and 400watts of panels will not get you what you need to properly charge the batteries.

What is your daily watt hour requirements? From there we can help you design your battery system, charging controls and panel array wattage.

[jimmyh]

OK now you figured out a green I am on solar set up. Thank you for bearing with me.

I use 50 watts 24 hours a day. And an additional 125 about 10 hours a day.

Is that 2450 watt hours?

[SunEagle]

OK now you figured out a green I am on solar set up. Thank you for bearing with me.

I use 50 watts 24 hours a day. And an additional 125 about 10 hours a day.

Is that 2450 watt hours?

Yep that is correct. You should also add a couple more watt hours based on the inverter and charging losses.

But for simplicity sake a system that needs to produce ~ 2.5kWh daily using only 20% DOD will require a battery system rated 24volt and 520Ah. And a 60 Amp MPPT charge controller with at least 1400 panel wattage. More depending on where you live and what your shortest day provides in useful sunlight.

[paulcheung]

Well he is Mexico, He can get 1000watts panels and a 40 amps MPPT charge controller. for 24 volts bank.

[jimmyh]

Thanks SunEagle. Since we only use the place 5 days every 2 months we underpowered the charging and focused on batteries and the generator backup.

Sure it is not optimal, but we rarely see the bank go below 12v. When we do it is geni on to power load and charge batteries for a few hours.

[mapmaker]

OK now you figured out a green I am on solar set up. Thank you for bearing with me. I use 50 watts 24 hours a day. And an additional 125 about 10 hours a day. Is that 2450 watt hours?

Generally speaking, a power usage of 2450 wh per day does require a 24 volt system. If you really never use more than 200 watts at a time, you may get by just fine with a 12 volt system. However, depending on your choice of batteries you may be much better off with a 24 volt system. There are two reasons: 1) you need at least 12000 wh of battery storage (assuming lead acid batteries) to support a 2450 wh per day load. If you want to do that at 12 volts you need a 1000 ah battery bank, if you want to do that at 24 volts you need only a 500 ah battery bank. You should avoid parallel batteries. If your battery of choice was a 500 ah 6 volt battery, you would need 4 of them. The storage capacity of four 500 ah 6 volt batteries is the same whether you put them in series, in parallel, or in series/parallel, but the lifespan of the battery bank will be longest if they are in series. That means 24 volts. 2) Most controllers are rated by their output amperage. A single 60 amp controller will be able to charge a 24 volt battery bank, but you will need two of those controllers to charge a 12 volt bank. --mapmaker

[jimmyh]

Thanks for all the great info. Next round will be 24v when I retire and spend more time at the Casa