Battery Bank/ Inverter Question
My goal is to build a semi-portable system to transfer between my house and my trailer. I have twelve 285W Silevo solar panels four of which I will be mounting on the trailer and eight for the house....
Forum Discussion
"What I am hoping to do is to configure the four batteries in series for 24V to be able to maximize the power harvest of the eight solar panels at my house (the Midnite string sizing tool will allow this 24V battery configuration with four parallel strings of two panels). If I drop the battery bank down to 12V I can only use four panels at a time."
I think I finally figured this out-- ?
OK, I get that the controller can do twice the watts with 24 than with 12. This is because the amps out is the same, and the controller has the same amps limit either way.
However, the Voc limit stays the same too, so the max number of panels you can use in series doesn't change between 24 and 12. The OP got me going by saying the number of panels changes.
So if he can only use four panels in series with 12 but he can use eight with 24, it is the power limit for 12v there and perhaps the Voc limit of the controller; he goes series/parallel to stay inside the same Voc limit when using eight with 24 at twice the power.
EDIT--I see he is using two- panel strings, so the Voc limit is with two, so his four on the RV must be also series /parallel.
The effective AH of the four batteries doesn't change so you could recharge them faster with the same amps at 24. But they won't act as storage any better for the four or eight panels. No idea how much storage is needed for the stick house. Just making it a 24v bank won't increase the storage capacity. It does allow you to have twice the power to use while it is coming in even if there is no place to store it all.
You need a certain amount of AH size bank to run the inverter in the RV. You need enough battery storage to get through the night. You need enough solar to run whatever during the day plus store some more for overnight.
I think I finally figured this out-- ?
OK, I get that the controller can do twice the watts with 24 than with 12. This is because the amps out is the same, and the controller has the same amps limit either way.
However, the Voc limit stays the same too, so the max number of panels you can use in series doesn't change between 24 and 12. The OP got me going by saying the number of panels changes.
So if he can only use four panels in series with 12 but he can use eight with 24, it is the power limit for 12v there and perhaps the Voc limit of the controller; he goes series/parallel to stay inside the same Voc limit when using eight with 24 at twice the power.
EDIT--I see he is using two- panel strings, so the Voc limit is with two, so his four on the RV must be also series /parallel.
The effective AH of the four batteries doesn't change so you could recharge them faster with the same amps at 24. But they won't act as storage any better for the four or eight panels. No idea how much storage is needed for the stick house. Just making it a 24v bank won't increase the storage capacity. It does allow you to have twice the power to use while it is coming in even if there is no place to store it all.
You need a certain amount of AH size bank to run the inverter in the RV. You need enough battery storage to get through the night. You need enough solar to run whatever during the day plus store some more for overnight.
