Problems with my Solar System seeking advice

[JSharpelle]

Hi all So I have been full time in my RV for about a year now and installed solar back in october, However Being totally new to both Solar and RV life i did not notice until recently that something is not adding up with my solar system my Charge Controller Never reads more than a trickle charge coming from the panels or going to the batteries and NEVER charges the batteries at higher than a Float charge as a matter of fact the maximum power i have ever seen my controller direct at my batteries is 13.2v! it should be dumping 14.6v during bulk and 13.8 during float based off its settings So let me outline my system and see if you guys can give me some idea's:


system consists of 2- 100w Genssi Flexible panels 18v 5.56 Amp Wired In parallel.



a no name PowMr 60 amp MPPT Charge controller (I bought it because it had 400 Good reviews on the website) and i intend to add more solar in the future so wanted to buy just one controller and not need to replace it if i added 4 or 6 more panels


and 4 103 Amp hour 12v Deep Cycle batteries wired in parallel for a 412 Amp hour bank


Now my problem is This ever since install the controller Will read a 1 amp Current at 21v which my panels are rated for a max of 21.9v. it would read that 1 amp Current morning till night. Initially i thought it was due to it being winter and not much light happening and didnt pay it much mind since we were plugged in at a campground all winter and a trickle charge was what was expected. So at high noon on the summer solstice i took another look and still just 1 amp 21v was being registered from the panels Resulting in something like a 1.8 amp charge rate to the battery anyway it was reading a total steady power generation of about 21 watts and a charge rate of the same. so i said there is definately something wrong so i disconnected the panels on the roof and i tested every connection, Voltage and amperage readings were good for the time of day along the wiring I got about 3.8 amps at the panels at 5:30pm and around 17v the numbered stayed the same at every connection (Y Connectors, Inline Circuit Breakers ETC) all the way to the controller, so i disconnected from controller and checked the reading at the last of the wiring and still maintained the numbers. After re-wiring my panels to the controller for shorter runs and replacing the green wire with red for the + (Store only had black and green when i first installed it!) now the charge controller will register UP to 2 Amps off the panels but every 45 seconds or so it resets to 21v 0 Amps then climbs back up to one if im lucky 1.8 amps before resetting to 0 again, my Batteries never reach higher than 75% although with our non existent power use that hasnt been a problem yet (LED lighting all we use electric for is lighting 12v Fridge circuit board water pump and to charge cell phones) i anticipate it becoming a problem


Now that my longwinded problem is laid out my thoughts are potentially faulty MPPT controller but as i am a noob to this i was hoping some one with more experience would help to guide me in the right direction

[757driver]

Originally Posted by JSharpelle

Hi all So I have been full time in my RV for about a year now and installed solar back in october, However Being totally new to both Solar and RV life i did not notice until recently that something is not adding up with my solar system my Charge Controller Never reads more than a trickle charge coming from the panels or going to the batteries and NEVER charges the batteries at higher than a Float charge as a matter of fact the maximum power i have ever seen my controller direct at my batteries is 13.2v! it should be dumping 14.6v during bulk and 13.8 during float based off its settings So let me outline my system and see if you guys can give me some idea's:


system consists of 2- 100w Genssi Flexible panels 18v 5.56 Amp Wired In parallel.



a no name PowMr 60 amp MPPT Charge controller (I bought it because it had 400 Good reviews on the website) and i intend to add more solar in the future so wanted to buy just one controller and not need to replace it if i added 4 or 6 more panels


and 4 103 Amp hour 12v Deep Cycle batteries wired in parallel for a 412 Amp hour bank


Now my problem is This ever since install the controller Will read a 1 amp Current at 21v which my panels are rated for a max of 21.9v. it would read that 1 amp Current morning till night. Initially i thought it was due to it being winter and not much light happening and didnt pay it much mind since we were plugged in at a campground all winter and a trickle charge was what was expected. So at high noon on the summer solstice i took another look and still just 1 amp 21v was being registered from the panels Resulting in something like a 1.8 amp charge rate to the battery anyway it was reading a total steady power generation of about 21 watts and a charge rate of the same. so i said there is definately something wrong so i disconnected the panels on the roof and i tested every connection, Voltage and amperage readings were good for the time of day along the wiring I got about 3.8 amps at the panels at 5:30pm and around 17v the numbered stayed the same at every connection (Y Connectors, Inline Circuit Breakers ETC) all the way to the controller, so i disconnected from controller and checked the reading at the last of the wiring and still maintained the numbers. After re-wiring my panels to the controller for shorter runs and replacing the green wire with red for the + (Store only had black and green when i first installed it!) now the charge controller will register UP to 2 Amps off the panels but every 45 seconds or so it resets to 21v 0 Amps then climbs back up to one if im lucky 1.8 amps before resetting to 0 again, my Batteries never reach higher than 75% although with our non existent power use that hasnt been a problem yet (LED lighting all we use electric for is lighting 12v Fridge circuit board water pump and to charge cell phones) i anticipate it becoming a problem


Now that my longwinded problem is laid out my thoughts are potentially faulty MPPT controller but as i am a noob to this i was hoping some one with more experience would help to guide me in the right direction

One thing that comes to mind is to try wiring your panels in series to have less voltage drop to your controller. Two 100 watt panels wired in parallel will not do much for your MPPT controller.

[JSharpelle]

I was Thinking of doing that as a Test Actually, Although i am reading no detectable voltage loss at the connection to the Controller i tested it both at the panels themselves and At the controller by disconnecting the wires from it and testing the voltage and amps there and i got matching values to the test at the panels performed 2 minutes earlier also my wire Run is about 7-9 feet panels to controller ( due to one panel being slightly further away there is a 2 foot Wiring difference) that is including the wires that came Pre-installed on the panels and another 7-8 ft From controller to Battery bank, my Eventual goal is to wire up a 1kw array with panels wired in Series-Parallel i just wanted to work out any issues and learn before spending money time and effort on a bigger system, the more components you have the more potential points of Failure especially when learning! I will re-wire for series tonight and test at noon tomorrow and see what happens

[JSharpelle]

Ok so I re-wired in series and took the following measurements from the wires connected to the terminals on the controller then I connected the wires waited a couple minutes and took the readings from the controller now it is 530 now so I think about half amperage is pretty expected from the panels new measurements tomorrow at lunchtime

[Persistent]

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[rarebear.nm]

Originally Posted by Persistent

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Why????

[JSharpelle]

Originally Posted by Persistent

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That is part of the problem if allowed to rest the batteries will read 12.5 to 12.6v however my onboard converter charger which is also an mppt system as we upgraded it over the winter will read it correctly and charge the batteries properly If you look at the pictures the controller is in the bulk stage not the absorbtion or float stages I believe the malfunction is either in the controllers circuit to read the pv input or its ability to read the battery voltage correctly as soon as the sun sets and the panels stop providing trickle charge batteries are at 70 to 75%

[JSharpelle]

Did I accidentally cancel something? I'm using forum on my phone and it keeps bouncing around as I'm replying

[rarebear.nm]

What gauge of wire did you use for both the down haul from the roof and from the controller to the batteries?

How old are your batteries and have you checked the water level assuming they are flooded lead?

Does the converter/inverter get the batteries back to 100%?

Solar can work very well. We have 460AHr battery pack, 1050 watt solar in three panels driving a Morningstar 60 A controller at 45 volts. Nearly always we are fully recharged (100%) by mid morning.

[Persistent]

Originally Posted by JSharpelle

… Charge Controller Never reads more than a trickle charge coming from the panels or going to the batteries and NEVER charges the batteries at higher than a Float charge as a matter of fact the maximum power i have ever seen my controller direct at my batteries is 13.2v! it should be dumping 14.6v during bulk and 13.8 during float based off its settings So let me outline my system and see if you guys can give me some idea's:

a no name PowMr 60 amp MPPT Charge controller
…
and 4 103 Amp hour 12v Deep Cycle batteries wired in parallel for a 412 Amp hour bank
…
since we were plugged in at a campground all winter and a trickle charge was what was expected.
…
Batteries never reach higher than 75% although with our non existent power use that hasnt been a problem yet (LED lighting all we use electric for is lighting 12v Fridge circuit board water pump and to charge cell phones) i anticipate it becoming a problem
…

I am not sure what you are saying here. You are plugged in at a campground all winter. Are you no longer plugged in?

If you are still plugged in, then a trickle charge is all you should expect.

If you are not plugged in, then the only number that seems strange is the 75% SOC. A 400 amp/hour battery bank is not going to be significantly discharged over night given the loads you cited. You may use less than 10% of battery capacity over night. Given high state of charge, low voltage (13.6) is appropriate. Low current is also expected. Bulk charge should never initiate.

A full charge of a lead/acid battery bank (10 to 100%) takes 14 to 18 hours regardless of the battery capacity. Lead/acid battery chemistry limits this. This assumes the charger can complete bulk charge in say 4 hours. The remaining 10 to 14 hours will be at low current and should not be applied above about 13.6 volts.

I can't explain the 75% SOC I would expect it to be near 90% after 10 hours of solar charging.

[JSharpelle]

Originally Posted by rarebear.nm

What gauge of wire did you use for both the down haul from the roof and from the controller to the batteries?

How old are your batteries and have you checked the water level assuming they are flooded lead?

Does the converter/inverter get the batteries back to 100%?

Solar can work very well. We have 460AHr battery pack, 1050 watt solar in three panels driving a Morningstar 60 A controller at 45 volts. Nearly always we are fully recharged (100%) by mid morning.

Batteries are under a year old water levels are perfect
8 guage wire from to controller run from controller to batteries 6 gauge is under 7ft roof run is 7 to 9 ft
Onboard charger gets them to 100% in just a couple hours no problem off shore power then drops to float voltage after disconnecting from shore if I disconnect batteries from rv at switch and let them rest they hold at 12.9 to 13v

[rarebear.nm]

Ok, looks like batteries are probably fine. In my mind your wire sizes are perhaps a little small. More so if you add more panels in the future. I used #4 for the down haul and double 0 for controller to battery.

I assume you have a shunt for the battery monitor? Is there a ground wire from any thing that does not pass through the shunt, excluding voltage sense wires?

[JSharpelle]

Originally Posted by Persistent

I am not sure what you are saying here. You are plugged in at a campground all winter. Are you no longer plugged in?

If you are still plugged in, then a trickle charge is all you should expect.

If you are not plugged in, then the only number that seems strange is the 75% SOC. A 400 amp/hour battery bank is not going to be significantly discharged over night given the loads you cited. You may use less than 10% of battery capacity over night. Given high state of charge, low voltage (13.6) is appropriate. Low current is also expected. Bulk charge should never initiate.

A full charge of a lead/acid battery bank (10 to 100%) takes 14 to 18 hours regardless of the battery capacity. Lead/acid battery chemistry limits this. This assumes the charger can complete bulk charge in say 4 hours. The remaining 10 to 14 hours will be at low current and should not be applied above about 13.6 volts.

I can't explain the 75% SOC I would expect it to be near 90% after 10 hours of solar charging.

No we have been dry camping since april not paying 30 to 50 a night for a campsite during the on season lol

And your correct we use almost no load we dont even have an inverter installed currently and only use 1 to 2 of our 2w lights at a time

[twinboat]

You can pick up a $20, 15 amp PWM controller and install it as a test.

If You get better results, then you know the MPPT controller is the problem.