48 volt battery charging

[Sunking]

Wouldn't 4 x 100 watt panels wired parellel not yield 400 watts? And increase to Amps?

Yes but PWM is only 67%. Your 4 battery panels in parallel at best will generate 22 amps. With MPPT I can generate the same current with 280 to 290 watts. Not only that I could use a single much less expensive grid tied panel.
.

[Nazproperties]

watts

I think you meant 200 watts right? I can build a 200 watt MPPT system for less than an equivalent 300 watt PWM system.

Wouldn't 4 x 100 watt panels wired parellel not yield 400 watts? And increase to Amps?

[Sunking]

The other half, is the charge controller. under 400w, it's cheaper to use the PWM style (70% efficient). Over 400W, MPPT is the suggested (95%) And if you go series, you will need MPPT to downconvert the 60V from the 4 PV's to 15v for battery charging.

I think you meant 200 watts right? I can build a 200 watt MPPT system for less than an equivalent 300 watt PWM system.

[Mike90250]

Power and current add in parallel. Parallel is less efficiency and cost more
Power and voltage add in series. Series is more efficient and cost less.

The other half, is the charge controller. under 400w, it's cheaper to use the PWM style (70% efficient). Over 400W, MPPT is the suggested (95%) And if you go series, you will need MPPT to downconvert the 60V from the 4 PV's to 15v for battery charging.

[Sunking]

Power and current add in parallel. Parallel is less efficiency and cost more

Power and voltage add in series. Series is more efficient and cost less.

[Nazproperties]

panel voltage output

With my 4 panel system, wired in parallel and each panel rated to produces 100 watts and Voc 21.6v and Vop 18v, is the output still going to be Voc 21.6v and Vop 18v and only increasing the watts to 400?

[SunEagle]

With my CC set at 12 volt and the 2 6 volt batteries wire in series for 12 volts would the connections be + on one battery and - on the 2 battery?

Yes. You would first connect the - of battery 1 to the + of battery 2. That gets you 12volts between the + of battery 1 and the - of battery 2.

Then connect your charge controller to the + of 1 and - of 2. You would connect your inverter to the same terminals.

[Nazproperties]

solar panel connections

And those batteries weight over 150 lbs where a 6v 232 Ah battery weighs about 60 lb max. Better get a small fork lift to move those 12volt ones around.

With my CC set at 12 volt and the 2 6 volt batteries wire in series for 12 volts would the connections be + on one battery and - on the 2 battery?

[SunEagle]

or you could just get one 8A4D 200Ah 12V AGM which can handle higher rates of discharge and charging for $380 instead of two 6V batteries.

or an 8A8D 245Ah 12V for $460 :
http://www.batterymart.com/p-12v-245...d-battery.html

And those batteries weight over 150 lbs where a 6v 232 Ah battery weighs about 60 lb max. Better get a small fork lift to move those 12volt ones around.

[ButchDeal]

Sounds like I need to change my thinking to 6 volt golf cart batteries X 2. Thank you everybody for all your input, this forum has really helped.

or you could just get one 8A4D 200Ah 12V AGM which can handle higher rates of discharge and charging for $380 instead of two 6V batteries.

or an 8A8D 245Ah 12V for $460 :

http://www.batterymart.com/p-12v-245ah-sealed-lead-acid-battery.html

[Nazproperties]

FWIW you can get 2 golf cart batteries which are 6 volt 225 AH for $300. That is more than twice the capacity of 100 AH

Sounds like I need to change my thinking to 6 volt golf cart batteries X 2. Thank you everybody for all your input, this forum has really helped.

[Sunking]

FWIW you can get 2 golf cart batteries which are 6 volt 225 AH for $300. That is more than twice the capacity of 100 AH

[SunEagle]

Have you any experience or an opinion of UPG batteries? (Universal Power Group)
I was looking at the: 12V 75Ah Group 24 - RBC14 SLA Rechargeable Battery - APC / UPS BATTERY - UB12750ALT4
Any opinion?

I own 4 of the UB12500 50Ah 12v batteries wired to make a 12volt 200Ah system. I haven't put them into a lot of use but they do hold their voltage in between charging.

I thought that using this type of battery was the way to go but after spending $400 for the 4 and using a parallel wired system I realized I should have gone with 2 6v 232Ah Interstate batteries (~$115/ea) in series. First off less expensive and second I didn't have to wire them in parallel.

If you need a 12volt system the cost for AGMs goes through the roof above 55Ah and they are real heavy. You might want to consider going with FLA in the 6v size. They will be less expensive and you have the ability to check their SOC with a hydrometer where you don't really know what the true charge state is for the AGM.

[Nazproperties]

Whats your budget? Be prepared for sticker shock as AGM's are expensive. Odyssey, Concord, and Optima are some of the better brands. Store brands are all mostly made with Interstate and John Controls.

A good 12 volt 100 AH AGM is going to cost you around $300 to $400 like these.

Have you any experience or an opinion of UPG batteries? (Universal Power Group)
I was looking at the: 12V 75Ah Group 24 - RBC14 SLA Rechargeable Battery - APC / UPS BATTERY - UB12750ALT4
Any opinion?

[Sunking]

OK, for all those that have proven to be well past me, I'm still looking for advice on 12 volt AGM 100Ah, or less, brand of battery. Energizer, Interstate, MK, ect...? I do, from time to time, travel to the big city (Phoenix) where I can find just about all brands.

Whats your budget? Be prepared for sticker shock as AGM's are expensive. Odyssey, Concord, and Optima are some of the better brands. Store brands are all mostly made with Interstate and John Controls.

A good 12 volt 100 AH AGM is going to cost you around $300 to $400 like these.