I'm confused and frustrated

[JeremyG]

Hello solar enthusiasts.

I've been learning about solar stuff for the last year (started in December 2022).
I started with 1 battery, 1 2000watt pure sine inverter & 1 100watt panel.
I since replacement that panel with 5 active, 230 watt panels (1150watts).
I had a couple used batteries, given to me by mechanics and they seemed to work well.
Late spring 2023+ through the summer and fall in south Ontario Canada, with a lot of consistent sun, things were going well beyond my expectations.
I was able to plug my kitchen fridge in 12-14 hours a day + all washing machine loads were all done with solar.
All usb devices were charged via solar.
We had a couple experiments where we plugged the living room tv + laptop into solar in the evening time and it worked (5 hours solid).

Numbers on the controller were solid 12's-13's an 14's.

Winter in south Ontario is often really cloudy (for months).
During winter, we haven't used the solar much.
The batteries kinda charge through the day...but not much. Barely able to charge our cellphones...so I've left it (making sure the controller keeps above 11 & 12).
The system shuts off if it dips under 10.5.

In the last couple weeks. We had a couple days when the sun was OUT, all day.
For the first time in months, the controller is showing numbers back in the 13's.

I currently have 2 Canadian Tire batteries and 3 princess auto batteries, plugged in parallel (red to red to red, black to black to black).

Yesterday, I saw the controller at 13.
I've been able to use my washing machine at that level of charge.
So...I happily did an extra small wash, mid day, not a cloud in site. Nothing else plugged into the system.
I spent time last week, making sure all the batteries were topped up with distilled water.
Even the lowest ones weren't that low.

The washing machine didn't last 10 minutes before the inverter started beeping and the controller was at 11.

I've been anxiously awaiting the sun to start coming back and start using the solar again. I've been building the battery bank up through the winter.
We have 7 total batteries.

I'll have to find the battery model numbers and specs to share with you.

The batteries charge fine...but they seem to lose charge too quickly.
Am I doing something wrong?
My oldest battery is 1 year old.
The others are all 6 months old.

Thank you for taking the time to read.
Any information you need, please let me know.
I'm anxious to get this thing working properly.


EDIT
I've got 2x moto master batteries, connected in parallel;
MOTOMASTER NAUTILUS Group 31 Deep Cycle Battery is a premium deep cycle battery
Engineered for power, stamina and reliability
Provides extended runtime for \"house\" accessories such as trolling motors, refrigerators and electronics
Group size 31
800 marine cranking amps, 100 amp hours, 185 minute reserve capacity
Dimensions: 13\" L x 6.75\" W x 9.50\" H (330 x 171 x 21mm)
Accessories ListTerminal Hardware
Advanced FeaturesCarry Handle, Serviceable Electrolyte
Amp Hours (10 Hour Rate)0.00 Ah
Amp Hours (20 Hour Rate)100.00 Ah
Amp Hours (5 Hour Rate) 0.00 Ah
Battery Capacity (@25AMP)190 A
Battery Capacity (@75AMP)0 A
Battery TypeWet/Flooded
Battery UseCycling

I've got 3 pro point batteries (currently disconnected in a desperate attempt to process of elimination, wondering if the moto master batteries, themselves will work better)

Item Name	27 DC Deep Cycle Battery
Cold Cranking Amps (A)	675
Type	Deep Cycle Battery
Part Number (BCI)	27 DC
Case Colour	Black
Packaging (qty)	1
Voltage Rating (V DC)	12
Case Material	Polypropylene
Reserve Capacity (minutes)	180
Battery Type	Lead acid
Cranking Amps (A)	840
Dimensions (in.)	12-13/16L x 6-3/4W x 9-13/16H

 

[Mattb4]

If you have not fully charged your LA batteries after discharge it will degrade them. They also need a equalizing charge every 10 days or so which your lack of solar power is likely not being able to accomplish.

If you have another way to charge other than solar I would recommend it. You might be able to regain some capacity.

 

[OzSolar]

For the first time in months, the controller is showing numbers back in the 13's

Hello!

Lead acid car batteries?

Whatever they are it sounds like they are chronically undercharged. I doubt they have been fully charged in months.

*Disconnect all the loads, turn the inverter off and let the solar charge the system until you see the controller get to float mode by 10 AM. It might take several sunny days or longer to get there. You may even need to unhook 1/2 of the batteries so you can actually charge the remaining ones.

You will do yourself a favor by investing in a Victron smart shunt and watching it closely.

 

[xjaw4]

Back

It would be good to have the following info

Voc on solar panels
ISC of panel
Vmp

Model number of charge controller
MPPT or PWM


If your panels are a used residential 60 cell ~ 36v VOC type of unit and your charge controller is a PWM type then ..

That sort of system will be limited to significantly less than the name plate rated wattage.

Ie 12V (battery voltage) times say 6 amps each panel .... such a system would only be able to deliver ~ 360 watts to the battery

Power equals voltage times current.

The solar panel power rating assumes that it is operating at the vmp voltage, when using a pwm charge controller the panel will be operating at battery voltage. When battery voltage is significantly different than vmp the power output will also be significantly less.
A 100 amp plus MPPT charge controller would be required to be able to deliver a full 1150 watts to the battery bank.


Batteries in parallel don't always share evenly and one weaker battery will drag the rest down until they too are weaker.


The inverter shutoff voltage of 10.X is typical for an inverter used in a service truck, RV or something where there is a V8 and a 100- 200 amp alternator ready to recharge the battery quickly.
This is not ideal for a solar setup where charging power is limited and for longer battery life it would be better to turn off the inverter at a much higher voltage so that the battery is not as deeply discharged.

If the batteries are left in a state where they are below 12V and not charged up to full regularly they will degrade and loose capacity.


It is possible your batteries are in this state.

Automotive starting batteries can deliver large currents for a short time to crank an engine but do poorly for extended loads.

Look at the RC rating on a car battery ( reserve capacity) how long in min it can power a 25 amp load.

 

[Rednecktek]

A couple things that come to mind:

That much panel needs about 100a of charge controller, what make & model is yours?

Getting bus bars involved will help your batteries balance better. It also gives you a good spot for your shunt to interface.

It sounds like you need a good equalization charge, which is going to be hard with solar because it needs quite a lot of power for a long time and the sun tends to go down and/or the timer on the controller runs out before it gets fully worked over. A good battery charger and running each battery one at a time through a repair process can get your batteries semi reset to a better starting position. Your entire bank will thank you.