mppt and amperage

Regarding the KID 30 amp controller...Midnite Solar says to only use 2 panels in a 12v set up. But if you put 3 in series and have about 105v
and 9 amps
to start...the KID isn't going to boost that to 30 amps..? or even to 25 amps..? Maybe 20-22...
so 3 in series wouldn't hurt a 12v set up...no?
What do you think?
and 9 amps
to start...the KID isn't going to boost that to 30 amps..? or even to 25 amps..? Maybe 20-22...
so 3 in series wouldn't hurt a 12v set up...no?
What do you think?
Comments
What says to only use 2 panels?
Did you run your panels through Midnites string sizing tool?
MidNite Solar - KID Sizing Tool.
- Assorted other systems, pieces and to many panels in the closet to not do more projects.
2.1 Kw Suntech 175 mono, Classic 200, Trace SW 4024 ( 15 years old but brand new out of sealed factory box Jan. 2015), Bogart Tri-metric, 460 Ah. 24 volt LiFePo4 battery bank. Plenty of Baja Sea of Cortez sunshine.
2.1 Kw Suntech 175 mono, Classic 200, Trace SW 4024 ( 15 years old but brand new out of sealed factory box Jan. 2015), Bogart Tri-metric, 460 Ah. 24 volt LiFePo4 battery bank. Plenty of Baja Sea of Cortez sunshine.
2.1 Kw Suntech 175 mono, Classic 200, Trace SW 4024 ( 15 years old but brand new out of sealed factory box Jan. 2015), Bogart Tri-metric, 460 Ah. 24 volt LiFePo4 battery bank. Plenty of Baja Sea of Cortez sunshine.
Some people live in places that do not get as cold, typically just before sunrise. It can be simpler for 3 in series also.
A 12v battery is going to get more solar power to it when you use 2 panels in series compared to 3 if the panel numbers were equal.
Maybe 3 in parallel will work if the panel model was listed. It would be best.
There is higher conversion loss as the voltage increases with 3 panels in series for a 12vdc battery bank.
There is more to this also, as always....
htps://offgridsolar1.com/
E-mail [email protected]
Typically, these days, the PV module voltages are higher than they were say, 20 years ago. Also, it is usually easier to buy the higher voltage modules used for grid tie now. I find that 12V nominal PV costs more than these newer modules. Been while since I looked though.
That being said, 105 Voc at 25 degrees C ambient will only go up to 150 Voc at really cold temperatures.
For silicon, that is ~around~ 10 or 11% higher Voc at every drop of 25 degrees C or so as I remember. It would have to get pretty cold, like, -50 degrees C ? I may be a bit off on this but something like that.
Also, the higher the Vmp, (and Voc) the hotter the unit will get in general. If you are charging a 12V battery, I would try more panels (even number) in series-parallel if that works out which would take care of both problems.
I think the sizing chart/program may give a good idea what is going to happen ?
I think I would just move somewhere sunny. Solar works better where there is sun anyway.
boB
ws9876, can we get the specs from the back of the panel?
2.1 Kw Suntech 175 mono, Classic 200, Trace SW 4024 ( 15 years old but brand new out of sealed factory box Jan. 2015), Bogart Tri-metric, 460 Ah. 24 volt LiFePo4 battery bank. Plenty of Baja Sea of Cortez sunshine.
2.1 Kw Suntech 175 mono, Classic 200, Trace SW 4024 ( 15 years old but brand new out of sealed factory box Jan. 2015), Bogart Tri-metric, 460 Ah. 24 volt LiFePo4 battery bank. Plenty of Baja Sea of Cortez sunshine.
Canadian Solar 315 watt/KID controller/SOK LiFePo 12v
You need a model number! It would have saved alot of the time on this thread.
htps://offgridsolar1.com/
E-mail [email protected]