SOK 100aH Problem

[minics04]

I purchased an SOK Battery 100aH 1 1/2 years ago. I have been charging with 200w of solar with a Victron MPPT charge controller and using a Victron Smartshunt to monitor the capacity.
I have always had and used the rated capacity, usually down to 20% or so with no problems. This week, I used 47% with 53% capacity remaining and the battery shut off. This is on my camper, then I put the camper in the sun to recharge the battery and reset the smartshunt incase it was not reading correctly. The battery fully charged and the MPPT was into float. I tested and only get about 19aH out of the battery.

I contacted SOK and they said I cannot charge this battery with 200w of solar. The power is too low. They recommended using a lithium battery charger to fully charge the battery.

Why has it worked just fine for the last 1 1/2 years this way? I think the BMS or a cell has gone bad.

Any help would be great.

Thanks!

 

[740GLE]

What are the settings of the Victron CC?

Even if it goes to “float” at 13.0v she’s not fully charged.

 

[mikefitz]

The Victron charger has a history of previous days performance , charge power and maximum and minimum battery voltage. This could be used to establish how the charge system and battery is performing.
Before you decide the battery is at fault, review the rest of the system , is the battery reaching a high state of charge, that is reaching a voltage over 14 volts?. Is the watt hours produced the solar as expected? Are all the cables and connections making correct contact?
Are there unexpected voltage drops? Is the camper loading on the battery as expected?

It's possible the smart shunt is not set up optimally for solar charging, and even if correctly set up can accumulate errors.

200 watts of solar will charge the battery provided the charger settings are optimum , you have good solar conditions, and all the power is charging the battery. However its possible full charge will not be reached in a single day.

The battery may have a fault and by monitoring charge current, voltage, and power absorbed by the battery, it should be possible to verify that its faulty or not.

 

[minics04]

MPPT Settings are as follows:
Absorp 14.6v
Float 13.8v
Equal Volts 14.6v
Rebulk .04
Absorp Fixed
Absorp Time Fixed
Absorp time 15 mins
Trail Current Disabled
Equal Stop mode Auto
Max Equal 0 Mins
Temp Comp off
Low temp off

According to the smartshunt, I did hit 13.8v. So, it was fully charged.

 

[740GLE]

No, if the battery didn’t hit +14v in absorb/bulk it didn’t fully charge.

Remember the SCC to battery may have enough voltage drop to the battery that the SCC thinks it’s ready for float but in fact the battery is well under 100% SOC

It’s a 200w panel, what’s the max PV charging the SCC saw 100w?

 

[Sojourner1]

Keeping in mind with these prepackaged batteries you need to reach the 14.x voltage for x amount of time cell balancing. See manufacturer specs.
Is it possible that the capacity has dropped because the cells are out of balance ? , hard to say when you can't see what the individual cells are doing or can you?

 

[minics04]

I cannot see what the individual cells are doing.

All good tips and I am investigating still. Stay tuned.

 

[HRTKD]

MPPT Settings are as follows:
Absorp 14.6v
Float 13.8v
Equal Volts 14.6v
Rebulk .04
Absorp Fixed
Absorp Time Fixed
Absorp time 15 mins
Trail Current Disabled
Equal Stop mode Auto
Max Equal 0 Mins
Temp Comp off
Low temp off

According to the smartshunt, I did hit 13.8v. So, it was fully charged.

Most of us are using much more conservative settings. 14.2 volts absorb, 13.6 float. Charging to 14.6 volts is a bit hard on the battery. Be sure you turn OFF equalization. The 0 minutes setting of the Max Equal should do it.

I would not turn off the low temp cutoff. The BMS may not allow charging below 32°F but the charger shouldn't either unless you have a warming system.

You could have a bad cell. You would have to monitor the charging to see if the BMS of the battery cuts of the charge at a certain point.

Which Victron solar charge controller are you using?

 

[minics04]

HRTKD-Thanks! I took those settings from the Current Connected website.

Here is what I am using for settings:
First is the Victron Smartshunt
Second is the Victron MPPT

Any suggestions would be great!!!

Thanks!

 

[HRTKD]

It's been a while since I looked at my settings. I don't think I have expert mode enabled. Someone else will probably have a quicker answer for you as my equipment is at the storage lot at this time.