Low charging power after short circuit

[celedore]

The past few days I noticed my battery isn't charging much over 50%. And my invertor isn't trying. Usually it's running full tilt by 10 am and fully charged by about noon. I have 9 solar panels rated at about 3300 watts all together charging one lifepower4 100 AH rack battery. So it's been no problem getting a full charge quickly especially in the hot Arizona sun.

About 5 days ago, I noticed a short on my 12v power invertor output circuit, which wasn't fused. Wires had fused together and the 12v invertor went into protect mode. I separated the wires and the 12v invertor began working again. This is the only incident that has occurred that I am aware of.

Now, my display shows 334 volts, (not sure if this is normal for my system) about 50 watts and 0 amps charging power.

I checked my settings and reset the battery and EG4 invertor. Upon reset the invertor fans fire up and display shows some occasional higher sporadic higher voltage numbers 600, 350... then sits at about 250 for a few moments before nestling back down to a cool 50 watts.

I also turned off the battery and unplugged the solar panels for a hard reset to no avail.

Any insights would be greatly appreciated here.

UPDATE

Loads pull directly from the solar panels with no problem. I pulled 1500 watts and it came directly from the solar panels. Then disconnected the panels and pulled 1500 watts directly from the battery. No problem.

Then, the charging system fired up to replenish the power I pulled from the battery. The system thinks the battery is fully charged at 53%. The 50 watts were registering is the idle usage.

Why would my system stop charging the battery at 53%?

 

[sunshine_eggo]

The past few days I noticed my battery isn't charging much over 50%. And my invertor isn't trying. Usually it's running full tilt by 10 am and fully charged by about noon. I have 9 solar panels rated at about 3300 watts all together charging one lifepower4 100 AH rack battery. So it's been no problem getting a full charge quickly especially in the hot Arizona sun.

A 100ah LFPpower4 battery is 48V, no? so you have two inverters?

About 5 days ago, I noticed a short on my 12v power invertor output circuit, which wasn't fused. Wires had fused together and the 12v invertor went into protect mode. I separated the wires and the 12v invertor began working again. This is the only incident that has occurred that I am aware of.

How are the 12V and 48V inverters connected?

Now, my display shows 334 volts, (not sure if this is normal for my system) about 50 watts and 0 amps charging power.

should be about 9 * panel Voc - probably a little less due to "hot Arizona sun"

I checked my settings and reset the battery and EG4 invertor. Upon reset the invertor fans fire up and display shows some occasional higher sporadic higher voltage numbers 600, 350... then sits at about 250 for a few moments before nestling back down to a cool 50 watts.

Volts or watts?

I also turned off the battery and unplugged the solar panels for a hard reset to no avail.

Any insights would be greatly appreciated here.

is the battery hot too? It is in communication with the 48V inverter? If so, it may be restricting charge based on elevated temperature.

 

[timselectric]

A 100ah LFPpower4 battery is 48V, no?

They come in 12v, 24v, and 48v.
The 12v is 400ah.

 

[celedore]

A 100ah LFPpower4 battery is 48V, no? so you have two inverters?

The system is installed on a converted bus/ motorhome. The 120v EG4 invertor feeds the circuit breaker. The 12v invertor, no, excuse me, convertor, feeds from the 120v breaker box.

 

[celedore]

should be about 9 * panel Voc - probably a little less due to "hot Arizona sun"

Yes there are 9 panels. I updated the post after doing some research. The 334 volts is perfect

 

[celedore]

A 100ah LFPpower4 battery is 48V, no? so you have two inverters?




How are the 12V and 48V inverters connected?



should be about 9 * panel Voc - probably a little less due to "hot Arizona sun"



Volts or watts?



is the battery hot too? It is in communication with the 48V inverter? If so, it may be restricting charge based on elevated temperature.

It is in communication with the invertor. Is 53% the "hot battery" charge limit?

 

[celedore]

Volts or watts?

Watts

 

[celedore]

To sum this whole thing up.. I could have just asked why my lifepower4 battery would just stop charging at 53%.

 

[celedore]

I'm not getting a warning code for "temperature too high"

 

[sunshine_eggo]

The system is installed on a converted bus/ motorhome. The 120v EG4 invertor feeds the circuit breaker. The 12v invertor, no, excuse me, convertor, feeds from the 120v breaker box.

Ah. Unlikely to have any effect on the EG4.

Is 53% the "hot battery" charge limit?

No idea. We're on this adventure with you.

To sum this whole thing up.. I could have just asked why my lifepower4 battery would just stop charging at 53%.

Which would only require us asking more questions, so thank you for not. The inverter model and installed PV is helpful.

I'm not getting a warning code for "temperature too high"

It might not be a warning. It might just be throttled based on temperature. My Victron Quattros will de-rate on inverter power at elevated temperatures. They do not tell you that. They just do it.

1. Is the battery in a climate controlled area, or is it subject to "hot Arizona sun?"
2. Does it report temperature?
3. What is the voltage when the battery indiates 53%?
4. What part of AZ? Our spot is near Concho Valley.

 

[celedore]

Taking 54% today.... charged by 9 AM before the heat of the day.

Battery voltage 56.4

 

[celedore]

Ah. Unlikely to have any effect on the EG4.



No idea. We're on this adventure with you.



Which would only require us asking more questions, so thank you for not. The inverter model and installed PV is helpful.



It might not be a warning. It might just be throttled based on temperature. My Victron Quattros will de-rate on inverter power at elevated temperatures. They do not tell you that. They just do it.

1. Is the battery in a climate controlled area, or is it subject to "hot Arizona sun?"
2. Does it report temperature?
3. What is the voltage when the battery indiates 53%?
4. What part of AZ? Our spot is near Concho Valley.

1) Not in a climate controlled environment.
2) No temperature report for me to access.
3) 56.4v
4) Tubac, AZ

 

[celedore]

EG4 is installed on top of the battery.
Stuck a thermometer in between. Reads 110.
I'm making space between the EG4 and battery to see if that helps.

 

[sunshine_eggo]

110°F is pretty brutal. This is greater than 40°C, which is the maximum recommended operating temperature for LFP. Absolute maximum for your battery is 50°C (122°F) for charging.

56.4 is > 3.50V/cell. Can you confirm the individual cell voltages are at or above 3.50V? If so, the battery is misreporting the SoC. Cells sitting at 3.50V are either fully charged or so close, it doesn't matter.

I suspect it's warmer internally than the 110°F you measure externally.

If there's any possibility of getting them into a controlled temperature or cooling them via other means, I vigorously recommend it. Your inverter is also probably very warm.

 

[celedore]

110°F is pretty brutal. This is greater than 40°C, which is the maximum recommended operating temperature for LFP. Absolute maximum for your battery is 50°C (122°F) for charging.

56.4 is > 3.50V/cell. Can you confirm the individual cell voltages are at or above 3.50V? If so, the battery is misreporting the SoC. Cells sitting at 3.50V are either fully charged or so close, it doesn't matter.

I suspect it's warmer internally than the 110°F you measure externally.

If there's any possibility of getting them into a controlled temperature or cooling them via other means, I vigorously recommend it. Your inverter is also probably very warm.

I created some space between the invertor and the battery and some space under the battery.

The battery began taking a little more each day. Now it's at 63%

I also reduced the maximum charging amperage down to the minimum 20A. (Instructions say i could go down to 10A but i don't have the option on the invertor.)

I suspect the rapid charge in the heat began charging the cells unevenly. 3300 watts of panels on a single 48v battery is a very rapid charge. Almost 70 Amps if my calculation is correct, 3300/48. This thing needs to trickle charge and I'm not sure how to do that since I can't set the charging amps under 20.

 

[sunshine_eggo]

I created some space between the invertor and the battery and some space under the battery.

If still outside, it's still likely very warm.

The battery began taking a little more each day. Now it's at 63%

I also reduced the maximum charging amperage down to the minimum 20A. (Instructions say i could go down to 10A but i don't have the option on the invertor.)

I suspect the rapid charge in the heat began charging the cells unevenly.

This isn't really a thing. All cells must pass the exact same amount of current and therefore take on the same amount of charge. There are subtleties where higher states of charge can lose coulombic efficiency compared to lower SoC cells, but this is almost certainly not the case in this situation.

3300 watts of panels on a single 48v battery is a very rapid charge. Almost 70 Amps if my calculation is correct, 3300/48.

Amps would be power / battery voltage: more like 3300/55.2 = 59.8A

But that's ONLY at high noon in perfect conditions. Your array is likely only putting out 70-80% max rated due to the impact of elevated temp on the cells.

This thing needs to trickle charge

It likely needs to be cooler.

and I'm not sure how to do that since I can't set the charging amps under 20.

20A should be more than enough.

56.4 is > 3.50V/cell. Can you confirm the individual cell voltages are at or above 3.50V? If so, the battery is misreporting the SoC. Cells sitting at 3.50V are either fully charged or so close, it doesn't matter.

Can you confirm this? this will determine if the issue is actually failing to charge or if it's misreporting SoC.

 

[celedore]

It likely needs to be cooler.

Yes and rapid charging creates more heat.

 

[celedore]

This isn't really a thing. All cells must pass the exact same amount of current and therefore take on the same amount of charge. There are subtleties where higher states of charge can lose coulombic efficiency compared to lower SoC cells, but this is almost certainly not the case in this situation.

I'm going to accept this as a good thing. But then tell me what it is about a trickle charge that is good for a battery compared to a rapid charge of is not heat and the even distribution of power between cells.

 

[celedore]

Can you confirm this? this will determine if the issue is actually failing to charge or if it's misreporting SoC

I will check, thanks. It doesn't appear to be misreporting based on the amount of power I'm getting out of the battery.

 

[sunshine_eggo]

Yes and rapid charging creates more heat.

On these low resistance cells, it's not a lot, but high ambient means the battery can't shed heat to a cooler sink. Current isn't the fundamental issue. A battery in a hot environment is. A battery in a hot environment has additional limitiations.

I'm going to accept this as a good thing.

It is.

But then tell me what it is about a trickle charge that is good for a battery compared to a rapid charge of is not heat and the even distribution of power between cells.

All cells in series must experience the exact same current, or you have violated major physical laws. Power is current * voltage, so there is no variation in "power distribution" on the basis of charge rate. The sole benefit of "trickle charging" is heat related.

I will check, thanks. It doesn't appear to be misreporting based on the amount of power I'm getting out of the battery.

Please elaborate. These two characteristics are not correlative. The battery will put out rated power over an incredibly wide range of SoC if not the full 0-100% range.

When all cell voltages are outside of the 3.10 - 3.40V, voltage has a decent correlation with SoC.

If you are seeing a total battery voltage of 56.4V, which is an average of 3.525V/cell, and the battery isn't reporting full or near full charge, the battery is DEFINITELY misreporting SoC.