diy solar

diy solar

Am I making sense here ?

I understand, but he mentioned the current setup has been running for years in 2S2P, so either he is really lucky, or the controller is under rated. South Texas stays pretty warm, but I know they got cold temps this year when Texas was frozen. I don't think adding another two panels in 2S configuration is going to change the risk he is already taking?

The safe bet would be as you mentioned. Get a second controller and run both 3P.
That is the "new" plan ....3p / 3p .... Thanks all
 
I understand, but he mentioned the current setup has been running for years in 2S2P, so either he is really lucky, or the controller is under rated. South Texas stays pretty warm, but I know they got cold temps this year when Texas was frozen. I don't think adding another two panels in 2S configuration is going to change the risk he is already taking?

The safe bet would be as you mentioned. Get a second controller and run both 3P.
both 4P would also be a viable option wouldn't it ?
thx
 
both 4P would also be a viable option wouldn't it ?
thx

4P would equal ~38v at ~40a and 1340w and push 56a at 24v into the batteries. The controller should be fine, but that is a lot of juice into the battery pack depending on how big it is.


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4P would equal ~38v at ~40a and 1340w and push 56a at 24v into the batteries. The controller should be fine, but that is a lot of juice into the battery pack depending on how big it is.


View attachment 53007

My battery bank is 14-12v wired in 24v ...thanks for the info
I understand ....but I don't see where the 56a you mention comes from .... i am a rookie here (obviously)
 
My battery bank is 14-12v wired in 24v ...thanks for the info
I understand ....but I don't see where the 56a you mention comes from .... i am a rookie here (obviously)

What chemistry is your battery?

"I have a 1400ah 24v bank"

56A would be a high charge rate for a 100 Ah bank, but for 1400 Ah it is only 0.04C
That's fine for lithium, too low for FLA. Probably OK for AGM and Gel but need to review charging recommendations.
 
My battery bank is 14-12v wired in 24v ...thanks for the info
I understand ....but I don't see where the 56a you mention comes from .... i am a rookie here (obviously)
volts x amps = watts
24v x 56a = 1344w
 
4P = 1340w (assuming you get a banner output). The controller will take that 1340w and convert it into 24vdc to charge the batteries.

1340w/24v=56a of charging. As long as your battery is big enough to take 56a at once, you will be fine.
 
What chemistry is your battery?

"I have a 1400ah 24v bank"

56A would be a high charge rate for a 100 Ah bank, but for 1400 Ah it is only 0.04C
That's fine for lithium, too low for FLA. Probably OK for AGM and Gel but need to review charging recommendations.
AGM SLA
I do appreciate your time here
 
AGM SLA
I do appreciate your time here

You're welcome!

You should check technical manual for your battery.
For mine (SunXtender) it says on page 20 that if charge rate is less than 0.2C, after absorption an additional 0.02C for no more than 1 hour will help. Don't know how you can program that in an SCC, however. More PV would be good if you can add it.


My system has excess PV, and bulk charging is normally a constant 0.2C
 
You're welcome!

You should check technical manual for your battery.
For mine (SunXtender) it says on page 20 that if charge rate is less than 0.2C, after absorption an additional 0.02C for no more than 1 hour will help. Don't know how you can program that in an SCC, however. More PV would be good if you can add it.


My system has excess PV, and bulk charging is normally a constant 0.2C
 
It says max charge rate 0.3C (30A for 100 Ah), at 25 degrees C, 14.5 - 14.9 V
This page doesn't say how long for absorption. We would usually give it 2 to 4 hours before dropping to float voltage.
It also doesn't address impact of lower charge rate.
Some people say it takes a very long time to properly recharge lead-acid.
Maybe they have more details in another document?

Approximately 500 cycles to 50% DoD.
 
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