LiTime lithium solar charging problem

[mark_f]

Hi to everyone, new to the forum. I first off apologize for not searching the forum for possible fixes but I've been fighting this for two weeks now, googling, AI-ing and YouTubing and have learned a lot about solar and batteries, just not what I need to know. Here's my 12v setup
GoPower 190W panel
GoPower 10a controller
WFCO 2kw inverter
Two LiTime 12v 100ah smart batteries
Everything was original except the batteries. I find the LiTime app to be difficult to figure out and after much hair pulling I finally got the two batteries to discharge evenly. Now, they charge good on shore power (app displays steady "charging" but from the controller they both Everything was original except the batteries. I find the LiTime app to be difficult to figure out and after much hair pulling I finally got the two batteries to discharge evenly. Now, they charge good on shore power (app displays steady "charging" but from the controller they both flash between "standby" and "charging" (according to the app, which I don't trust)

 

[sunshine_eggo]

You have duplicated text in your post. Kinda confusing.

What's your actual issue?

You have both your main leads on the same battery. This is not correct. You need to connect "across" both batteries. Move indicated cable to other battery:

 

[mark_f]

Sorry!! That was the wrong pic. It's now like this

 

[sunshine_eggo]

Sorry!! That was the wrong pic. It's now like thisView attachment 266972

That explains why it wasn't balanced, but it is now.

So what's the actual problem with solar charging?

 

[Solar Guppy]

Insufficient solar would be my guess, you have 200Ah of batteries and at best 10Ah of charging, likely much less this time of year. Additionally, a 10Ah charger would be pwm, not mppt, so with no loads, 3-4 days to charge best case.

 

[mark_f]

That explains why it wasn't balanced, but it is now.

So what's the actual problem with solar charging?

The controller says it's pumping 13.4v to the batteries but the app is saying they're on standby at around 32%, same as six hours ago

 

[mark_f]

Insufficient solar would be my guess, you have 200Ah of batteries and at best 10Ah of charging, likely much less this time of year. Additionally, a 10Ah charger would be pwm, not mppt, so with no loads, 3-4 days to charge best case.

So if I switched out the controller for a 30a MPPT, you would expect a more responsive charge rate?

 

[sunshine_eggo]

The controller says it's pumping 13.4v to the batteries but the app is saying they're on standby at around 32%, same as six hours ago

The controller is reporting what is used both for charging and loads.

LFP takes on more charge at lower voltages - almost all charging occurs below 13.8V, and the voltage rise is slower than pain drying.

Furthermore, as @Solar Guppy indicated, you have very little PV for 200Ah of LFP.

Your 190W panels in perfect conditions can only output about 1kWh/day in summer - less in winter. It's likely that you're using more than this, and you're just never getting anywhere near full charge.

Lastly, some BMS are very poor at measuring current. If each battery is getting less than 2A, then they may not register it at all.

So if I switched out the controller for a 30a MPPT, you would expect a more responsive charge rate?

Not much. 190W / 12.8V = 14.8A = the maximum you can expect with your 190W panel in perfect conditions (that don't exist).

 

[Solar Guppy]

So if I switched out the controller for a 30a MPPT, you would expect a more responsive charge rate?

You have 2560 watt/hour of battery ( likely less as you can't run down to zero ) and probably ~100 watts of solar per hour when in full sun with pwm controller. Going mppt might get 25% more, but more solar and mppt are really needed. You haven't even mentioned what your loads are, so it's hard to offer a more exact suggestions.

 

[sunshine_eggo]

You have 2560 watt/hour of battery ( likely less as you can't run down to zero ) and probably ~100 watts of solar per hour when in full sun with pwm controller. Going mppt might get 25% more, but more solar and mppt are really needed. You haven't even mentioned what your loads are, so it's hard to offer a more exact suggestions.

Assuming:

190 watt Solar Module

The high-efficiency, 190 watt Solar Module from Go Power! provides outstanding solar power for off-grid and mobile applications.

gopowersolar.com

20.4Vmp forced to work at 13.4V means 13.4V * 9.45A = 127W max.

 

[mark_f]

To me this is rocket science. I don't have enough electrical knowledge/understanding to make e sense of it. I'm going to do some more studying. Thanks for your replies

 

[sunshine_eggo]

To me this is rocket science.

Not really, but it does need to be learned, and if you don't have a basic understanding of electricity:

Voltage, V = Current, I * Resistance, R (V = I * R)

AND

Power, P = Current, I * Voltage, V (P = I * V)

It's going to be difficult.

Will has this 26 minute video that might be worthwhile:

I don't have enough electrical knowledge/understanding to make e sense of it. I'm going to do some more studying. Thanks for your replies

I'll elaborate on the difference between the two main types of controllers. You have a PWM:

PWM controllers are not smart charge controllers. They simply short the panel to the battery and directly deliver whatever current the panel can provide. This often results in a large penalty because the battery voltage is lower than the panel voltage.

MPPT controllers are fancy DC-DC converters that convert the higher voltage/lower current of the panel to the lower voltage/higher current of the battery and extract the maximum power available from the panel at any given time.