Need Solar Guru Help!

[campermama]

This is my system...

570w solar panels (parallel)
?2 100ah BB lithium (parallel) (12v)
Victron smartsar 100/50 controller
Renogy battery monitor
Renogy 2000w inverter

Victron goes through bulk mode until it reaches absorption V, then goes to absorption mode for 1 hr (recommended by BB), (highest V I have seen on the monitor during absorption mode is 13.5, while mppt reads 14.4)then it goes to float (mppt reads 13.6v, monitor reads 13.4v), the amps never go down to 0, it sticks around at 2-4 amps. So to me it seems batteries are never "fully" charged?

V always drops to 13.2(something) v when it gets dark. According to charts I have seen that is only 70%!
ALSO, discharging amps at night seem really low....TV, inverter on, led lights on, it shows - 1.8 amps, how can that be?

Here is a "drawing" of my set up....

My 12v System

[campermama]

3 tons wrote:


Well I find that rather odd since I live near by and was at BattkeBorn when they handed me my victron charge controller and they’d advance pre-programmed it for exactly what the Victron user manual called for, and mine works perfectly - it must depend on which day of the week you speak to the BB fella’s - I donno?…

3 tons

Here it is...

=https://battlebornbatteries.com/programming-a-victron-smartsolar-charge-controller

[3_tons]

campermama wrote:

3 tons wrote:
Make sure the rotary selector switch on your charge controller set to position #7…

3 tons

Not using rotary switch, the setting are not what BB recommends so using user settings

Well I find that rather odd since I live near by and was at BattkeBorn when they handed me my victron charge controller and they’d advance pre-programmed it for exactly what the Victron user manual called for, and mine works perfectly - it must depend on which day of the week you speak to the BB fella’s - I donno?…

3 tons

[CA_Traveler]

WAG The 0.9V drop from your MPPT to the monitor/battery results in the batteries not being fully charged and resutls in the 4.5A monitor reading which is the best charging it can do given the voltage drop.

Also suggest you check your 3x panel Voc vs the 100V MPPT input and see if you can connect the panels in series.

[otrfun]

campermama wrote:

otrfun wrote:

campermama wrote:
Don't have a clamp on meter, mppt programmed to BB recommendations

That's too bad. It's very hard to properly troubleshoot a system like yours without a DC clamp-on ammeter. Good luck.

Sorry I don't have the right tools for you to help me. I will purchase one when I am somewhere where I can get one. I'm currently on the road. Thanks anyway.

You're welcome. No apologies necessary. Do what works best for you. Be safe!

[campermama]

otrfun wrote:

campermama wrote:
Don't have a clamp on meter, mppt programmed to BB recommendations

That's too bad. It's very hard to properly troubleshoot a system like yours without a DC clamp-on ammeter. Good luck.

Sorry I don't have the right tools for you to help me. I will purchase one when I am somewhere where I can get one. I'm currently on the road. Thanks anyway.

[campermama]

Just looking for any ideas you guys may have as to what could possibly cause my issue.

[otrfun]

campermama wrote:
Don't have a clamp on meter, mppt programmed to BB recommendations

That's too bad. It's very hard to properly troubleshoot a system like yours without a DC clamp-on ammeter. Good luck.

[campermama]

Don't have a clamp on meter, mppt programmed to BB recommendations

[otrfun]

campermama wrote:
That's what i am looking at at night, a shunt monitor. I don't need/want to calculate SOC based on V. I'm just looking at what the monitor is telling me and trying to figure out why it's reading 13.2v instead of 13.3 or 13.4 after charging all day.

I assume all the voltage and current readings you're referencing were taken from the battery monitor display and/or Victron controller?

Me, I'd verify charge current (mid-day sun with max charge current) at the battery terminal (before the shunt if measuring at the neg terminal) with a DC clamp-on ammeter. I'd also verify battery charge voltage (mid-day sun with max charge current) at the battery terminal (before the shunt if measuring at the neg terminal) with a voltmeter.

I'd make the same voltage/current checks while doing a high c discharge with your inverter, too.

Do these readings correspond with the voltage/current readings on your monitor (charge and discharge) and/or controller (charge only)?

Did you program your Victron controller with any specific charge profile or voltage(s)?

[otrfun]

2oldman wrote:

otrfun wrote:
lifepo4's not needing absorption---that was the lifepo4 charging philosophy a 2-3 years ago when nearly all lifepo4 converters/chargers were single-stage 14.6v (no absorption or float stage).

Also interesting is the 48v Dakota charger appears to have bulk only, so perhaps it depends on the kind of Li battery. But, I'm getting off the subject.

Very possible. Many times manufacturers will recommend different operational specs based on a battery's specific application.

More to my point . . . if a standard lifepo4 (lithium iron phosphate) cell (with a typical 2.5v LVD and 3.65v HVD) is used by a battery manufacturer, and the manufacturer recommends only bulk charging at 14.6v, I assure you they're recommending this at the expense of cycle life. Charging a lifepo4 cell at 3.65v (Maximum Rated Charge Voltage), or a 12v lifepo4 battery at 14.6v, 24/7/365, will reduce cycle life short-term, and permanently damage the cell/battery long-term.

[campermama]

3 tons wrote:
Make sure the rotary selector switch on your charge controller set to position #7…

3 tons

Not using rotary switch, the setting are not what BB recommends so using user settings

[campermama]

That's what i am looking at at night, a shunt monitor. I don't need/want to calculate SOC based on V. I'm just looking at what the monitor is telling me and trying to figure out why it's reading 13.2v instead of 13.3 or 13.4 after charging all day.

[3_tons]

Make sure the rotary selector switch on your charge controller set to position #7…

3 tons

[otrfun]

campermama wrote:

otrfun wrote:
Many 12v lifepo4 voltage/SOC charts show 13.20v (resting voltage) as equivalent to 70% SOC. The key here is "resting voltage".

Ok so the 13.2 is not really "resting", then would the actual "resting" voltage show a higher voltage or less?

After charging, final resting voltage will be lower. After discharging, final resting voltage will be higher. Higher charge/discharge current means a greater voltage delta (difference) to reach a given resting voltage.

Why do you need/want to calculate SOC based on voltage? A shunt-type battery monitor (properly calibrated) will calculate SOC much more accurately.

[campermama]

I have a renogy monitor - yes it shows - amps