MPPT controller and voltage drop?
Warning - long and technical. Trying to figure out the simplest way to get power from panels to MPPT Rogue, and brains are overheating already. Didn't want to continue this in my thread on roof to...
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I forgot to tell 60V total array voltage - but does it matter? Any 2 panels in series will have more than enough voltage after MPPT controller to get 14.8V output. RLMiller - it's 70ft total 2-way run to controller, so the voltage/wattage drop is quite measurable though unlikely to disturb my comfort.
Hopefully I won't get that much with 480W array. Not because of controller 30A limit (too late, have bought it already), but because I won't have a load higher than 10-11 A at any given moment. Mostly it will be "pure charging" in 60-100% SOC range, so with 2% wire loss + 4-5% controller loss the battery+load won't have a chance to pull more than 31-32A.
0.6 Ah a day was an estimate. 150 AH from 480W array on a good summer day (if I get lucky), so with 0.75% difference in watts output between Option #1 and #2, it means 0.0075*150/2 (if half a day it hits 30A) = 0.6 AH difference in daily harvest.
I guess there is nothing to worry. Marc the Rogue ;) just put in standard warnings in case if somebody would try and run 100V*8A over AWG 12 or other crazy things.
Btw, have found AWG 8 with MC4 in 75ft and 100ft length. Temptation...
RLMiller wrote:
The output from the MPPT converter to the battery {with 500W array} can run as high as 45 amps
Hopefully I won't get that much with 480W array. Not because of controller 30A limit (too late, have bought it already), but because I won't have a load higher than 10-11 A at any given moment. Mostly it will be "pure charging" in 60-100% SOC range, so with 2% wire loss + 4-5% controller loss the battery+load won't have a chance to pull more than 31-32A.
0.6 Ah a day was an estimate. 150 AH from 480W array on a good summer day (if I get lucky), so with 0.75% difference in watts output between Option #1 and #2, it means 0.0075*150/2 (if half a day it hits 30A) = 0.6 AH difference in daily harvest.
I guess there is nothing to worry. Marc the Rogue ;) just put in standard warnings in case if somebody would try and run 100V*8A over AWG 12 or other crazy things.
Btw, have found AWG 8 with MC4 in 75ft and 100ft length. Temptation...
