SOLAR OUTPUT ON SAILBOAT

Three years ago I installed 3 135 watt solar panels (flat, little/no obstructions) mated to a MPPT (Blue Sky) controller to help maintain my boat's battery bank (2 4D AGM's, approx 400 amp/hrs - 1.5 years old). The panels run separately to a below-deck bus bar via MC4 cables, then parallel to the controller (8 gauge wire) and then battery bank. While in the Bahamas I saw over 25-27 amps during peak sunlight hours. We are now in Florida (Stuart) waiting to cross to the Bahamas and even during peak production hours, only getting 16-18 amps. I've checked all the panels and they are equal in production (3-4+ amps), that number triples (3 panels) going into the controller and then gets that MPPT "boost" going to the battery bank. I keep the panels clean and all connections are corrosion free. Other than all three panels failing at the same time, I am baffled as to why the loss of close to 10 amps. I had a marine electrician (not necessarily a solar expert) check my system and he could find no problems. Any help from here would be much appreciated!
Comments
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KID #51B 4s 140W to 24V 900Ah C&D AGM
CL#29032 FW 2126/ 2073/ 2133 175A E-Panel WBjr, 3 x 4s 140W to 24V 900Ah C&D AGM
Cotek ST1500W 24V Inverter,OmniCharge 3024,
2 x Cisco WRT54GL i/c DD-WRT Rtr & Bridge,
Eu3/2/1000i Gens, 1680W & E-Panel/WBjr to come, CL #647 asleep
West Chilcotin, BC, Canada
Keep suggestions coming!!
KID #51B 4s 140W to 24V 900Ah C&D AGM
CL#29032 FW 2126/ 2073/ 2133 175A E-Panel WBjr, 3 x 4s 140W to 24V 900Ah C&D AGM
Cotek ST1500W 24V Inverter,OmniCharge 3024,
2 x Cisco WRT54GL i/c DD-WRT Rtr & Bridge,
Eu3/2/1000i Gens, 1680W & E-Panel/WBjr to come, CL #647 asleep
West Chilcotin, BC, Canada
Small systems like this can output more amps at lower voltage but can be harder to get amps out at bulk absorb. Just a guess.
You can test the short circuit current of each module and check if they have degraded.
http://members.sti.net/offgridsolar/
E-mail [email protected]