Lithium Battery Conversion Issues

[SirPuck]

I recently replaced two 6-Volt golf cart batteries with a 400ah lithium battery. I removed the golf cart batteries and installed the*Victron smart shunt (connecting the negative cables from the inverter/charger to the lithium battery negative terminal), connected the positive connection to the lithium battery, set the dip switches to "Gel Cell Cool" on the Heart Interface remote control panel.*
With shore power breaker turned off at the house, I turned on interior lights and started up a small floor fan.* Everything works fine for*just over an hour.* The fan stops working, lights are still on, and on the Charger/Inverter, the DC Amps light turns off, and the Battery light begins blinking.* About 10 minutes later the lights go off and the remote control panel becomes completely unresponsive.* The only way to reset it is by turning on the shore power and turning it off.* Then it'll do that process again.
I have checked the battery/terminal connections, and there are no*blown fuses that I can find. Attached are photos of the remote control panel for the Heart Interface before and after the issue.

According to the Heart Interface Freedom manual, it says the following is the issue:
Blinking Battery (12 Volt model):
Indicates either a shutdown or equalizing. Battery > 15.50
Volts, will auto-reset at 15.25 Inverter mode: Battery <10.00
Volts, will auto reset at charger float voltage or upon AC input.
Charger mode: Battery < 8.00 Volts for 1 minute, remove all
DC loads. If dip switch #4 is ON, reset by cycling the power
switch. If dip switch #4 is OFF, reset by disconnecting and
reapplying shore power.

Components
Litime 12V 400Ah LiFePO4 Lithium Battery 3200W Max. Load Power LiFePO4 Battery Built-in 250A BMS
Victron Energy BMV-712 Smart Battery Monitor (Black)
Heart Interface, Freedom 20D Inverter/Charger
Generator: Onan 7.5kW
Solar Panel
CoZroom LCD Solar Charger controller

I am hoping someone here can help me with a solution or troubleshooting. I've read that the Heart Interface Freedom aren't the best for Lithium batteris so hoping to solve this issue but hoping to avoid that costs.

Thank you.

[windsorbill]

Do you know what the voltage or SOC was on the battery when you started the test?

lithium batteries weren't even a dream back when your inverter was made. Have you reached out to mfg to see if they are compatible? My guess is not.

On a side note, how are you dealing with the engine alternator charging the new lithium's?

[Jon_C]

It would be best to get a charger with a lithium charging profile.

The before pic at 12.1 volts is less than 10% state of charge.

What your experiencing is normal due to the lithium battery not being fully charged.

Your gel cell setting shows 14.1v at bulk for 3 hrs which should charge to way more than 10%, if theres a manual equalization charge you may get more charge using that as well but I don’t think you’ll ever get to 100% with the existing charger.

Heres the lithium state of charge chart for reference.

[jberger]

Those Freedom units don't have the right profile for charging LFP batteries, but it seems like your issue on discharge. A fully charged 400ah battery should run those loads for quite a while before low voltage disconnect.

Does the BMS on the battery have a bluetooth connection you can monitor?
If it's a plus model, it should have bluetooth.

Is the victron shunt still working when the inverter is locked up or shuts down?
Does the battery have the built in heaters for self heating when cold?
Some of the Litime batteries with self heating options have been shown to have issues so that might be part of the problem here.

If the batteries aren't showing a fault and the shunt is reporting good voltage then it would point to DC Ripple causing the inverter to lock up.

[153stars]

The BMS can disconnect for low voltage possibly high input as well. Your sure not charger is trying to equalize.
Try to change gel back to. lead acid charge setting its only other change you made. Can you disable any scheduled equalize setting if any.

[Soppy]

At 12v , your lithium battery is dead. It is possible that the the internal BMS is shutting down the battery.

[Persistent]

The best solution is probably to replace the inverter/charger and the control panel with a new system.

The inverter is a “modified sine wave” type inverter. A new “pure sine” inverter will be better for modern 120 volt appliances.

The inverter/charger has wonderful automatic management for lead acid batteries. These functions become confused when you try to charge or discharge Li batteries.

Deeply discharged Li battery will not likely get balanced at the end of a charge cycle. It may or may not get balanced if only partially discharged. Li battery may need 14.4 volts at the end of a charge cycle to balance the Li battery cells. The charger you have only provides 14.1 volts at the beginning of the charge cycle and 13.6 volts after 4 hours. Different quality Li batteries need more or less balancing. As they get older, Li batteries need more balancing.

The Heart is not a modern design. It can be confused and may confuse the Li battery BMS.

All that said, none of this is likely causing the symptoms you reported.

I recently replaced two 6-Volt golf cart batteries with a 400ah lithium battery. I removed the golf cart batteries and installed the*Victron smart shunt (connecting the negative cables from the inverter/charger to the lithium battery negative terminal), connected the positive connection to the lithium battery, set the dip switches to "Gel Cell Cool" on the Heart Interface remote control panel.*

Smart shunt goes to Li battery negative terminal. Negative inverter/charger cable goes to other terminal of smart shunt.

"Gel Cell Cool" (14.1 for 4 hours 13.6 float) is the best the charger can do. The Li battery will likely not get balanced at the end of the charge cycle if battery is deeply discharged. However, this should not be causing the issue you report below.

With shore power breaker turned off at the house, I turned on interior lights and started up a small floor fan.* Everything works fine for*just over an hour.* The fan stops working, lights are still on,

Translates: Inverter shut “off”. Battery continued to supply 12 volts for lights.

and on the Charger/Inverter, the DC Amps light turns off, and the Battery light begins blinking.*

Most likely this indicates battery voltage dropped below 10.0 volts. Battery BMS may have disconnected and after inverter shut down, reconnected. See battery manual for possible reasons. Possibly, battery is nearly discharged and can no longer support the inverter.

About 10 minutes later the lights go off and the remote control panel becomes completely unresponsive.*

Battery finally went dead. Battery BMS shut “off” battery output.

The only way to reset it is by turning on the shore power and turning it off.* Then it'll do that process again.
I have checked the battery/terminal connections, and there are no*blown fuses that I can find. Attached are photos of the remote control panel for the Heart Interface before and after the issue.

Possibly, connecting to shore power provided a partial charge to the battery so the path to full discharge repeats.

Victron Energy BMV-712 Smart Battery Monitor (Black)

I am hoping someone here can help me with a solution or troubleshooting. I've read that the Heart Interface Freedom aren't the best for Lithium batteris so hoping to solve this issue but hoping to avoid that costs.

The Victron Monitor should show the battery terminal voltage precisely. (State of Charge reading will probably be incorrect.) Compare the monitor reading to the chart posted above in previous post. Is the Li battery fully charged? It it below 20%?

Fully charge the Li battery and try again.

The Victron Monitor brochure does not mention Li capability. It may not be able to be set to properly monitor state of charge of a Li battery. See Owner's Manual for possibilities.

[RoadTrip2084]

Some good advice above.

I am using the Heart Interface Freedom 20 with my 280ah LiFeP04 battery and it has been working well, using the same setting you are on. The battery will balance during charging but may require a longer charge time at the "top" with the lower 14.1 voltage. I also use a DC-DC charger while driving which is lithium aware so that helps I suppose. No issues with balance on my battery so far.

It sounds like your battery was almost discharged when you hooked it up and then its BMS shutoff due to low voltage. Did you check its charge level when you first turned it on?

First, I would make SURE you have your Equalization mode disabled and/or understand what actions on the panel could trigger it (re: manual). Under no circumstances do you want to enter an equalization using a LiFeP04 battery.

Then, I would plug in to shore power, and let the converter charge the battery for a complete charge cycle. Monitor the battery voltage/charge level as it goes to ensure things are working as expected.

I'm not familiar with the smart battery monitor you have, but my understanding is that they may require some kind of a reset step where you fully charge the battery and then reset itso it knows what "fully charged" looks like. Check the manual.

EDIT> Almost forgot, did you remove any other oem components that might combine the house/LiFeP04 battery with the chassis batteries? My rig had an oem battery isolator and chassis battery maintainer that I removed to make sure the two circuits were isolated.

[windsorbill]

OP,

I hope you come back and let us know how things are working. Unfortunately, you can seldom just R & R 6 volt batteries with Lithium and not do any other work. I hope whomever sold you that battery talked about what is involved. The additional costs (parts and labor) can be staggering. Your victron 712 is an excellent choice, but it has to be connected correctly to do it's designed job. You need to separate your chassis and house batteries (at least manage the charging of the lithium) when engine is running, otherwise you risk your alternator overheating and eventually failing. And the inverter/charger is really going to struggle to get that battery charged correctly, if at all.

I went through all that, but I knew what I was getting into before I started.

[Jon_C]

Heres a good read on charging lithium with LA chargers. My conclusion after reading this is a proper lithium charger is absolutely required. Interested to hear other opinions.

Return to bulk is a major issue and sounds like thats what happened to op.

It also says charger must be disconnected after every charge.

https://www.batteryworld.com.au/news...d-acid-charger

[RoadTrip2084]

Originally Posted by Jon_C

Heres a good read on charging lithium with LA chargers. My conclusion after reading this is a proper lithium charger is absolutely required. Interested to hear other opinions.

Return to bulk is a major issue and sounds like thats what happened to op.

It also says charger must be disconnected after every charge.

https://www.batteryworld.com.au/news...d-acid-charger

The Freedom 20 charge profile is okay for lithium. Basically at the lower 14.1v charge voltage it will lower the amps going to the battery as it reaches capacity, since the battery will eventually have a higher voltage itself than the charger can provide. It may end the charge cycle before the battery is fully charged, but that can be monitored and another charge cycle initiated manually if warranted.

Based on what the OP said, it didn't sound like he used the charger at all, he unplugged from shore power almost immediately and then used the battery until it presumably cutout (via its BMS) due to low voltage. aka the battery needs to be charged.

[SirPuck]

Thank you for all the input. My apologies for stepping away for a couple days.

Originally Posted by windsorbill

Do you know what the voltage or SOC was on the battery when you started the test?

lithium batteries weren't even a dream back when your inverter was made. Have you reached out to mfg to see if they are compatible? My guess is not.

On a side note, how are you dealing with the engine alternator charging the new lithium's?

According to the App, the voltage on the battery was at 12.66V. I can’t find where the manufacturer is around anymore to consult. I haven’t made it to testing to see if it will charge with the engine alternator. My hope is that it will charge that way because that is the way my previous setup was with the golf cart batteries.

Originally Posted by jberger

Does the BMS on the battery have a bluetooth connection you can monitor?
If it's a plus model, it should have bluetooth.

Is the victron shunt still working when the inverter is locked up or shuts down?
Does the battery have the built in heaters for self heating when cold?
Some of the Litime batteries with self heating options have been shown to have issues so that might be part of the problem here.

If the batteries aren't showing a fault and the shunt is reporting good voltage then it would point to DC Ripple causing the inverter to lock up.

Yes, it has a bluetooth connection that connects to the Victron app on my phone. When the inverter shuts down everything goes dark. The inverter/charger panel and the Victron app can't find the smartshunt. This battery does not have self-heating, that I know of at least.

Persistent - Thanks for the correction, yes, I connected the negative smartshunt battery negative terminal and negative inverter/charger cable goes to other terminal of smart shunt.

RoadTrip2084 - I can't find anything in my manual that discusses how to enable/disable equalization. And you are correct, I connected everything to the RV, connected it to my Victron app, and it shows at 100% charged. I will connect it to shore power for 24 hours or so and see if that solves my issues.

[SirPuck]

Originally Posted by RoadTrip2084

EDIT> Almost forgot, did you remove any other oem components that might combine the house/LiFeP04 battery with the chassis batteries? My rig had an oem battery isolator and chassis battery maintainer that I removed to make sure the two circuits were isolated.

I don't see a battery isolator or maintainer.. I do have an "Aux Start" but I assume that would be through the inverter/charger.

[RoadTrip2084]

Originally Posted by SirPuck

RoadTrip2084 - I can't find anything in my manual that discusses how to enable/disable equalization. And you are correct, I connected everything to the RV, connected it to my Victron app, and it shows at 100% charged. I will connect it to shore power for 24 hours or so and see if that solves my issues.

It's on page 14 of your manual:

"Stage 4 - Equalizing Charge This is the only battery charger stage which is not engaged automatically. It must be manually initiated each time it is necessary to equalize using a dip switch on the back of the Freedom Remote Control or the front panel on the Link Instrumentation. Applying an equalizing charge is not possible without the use of a Freedom Remote Panel or Link Instrument."

Sounds like you're fine, you'd have to take off your inverter panel and set a dip switch to engage equalization.

Originally Posted by SirPuck

I don't see a battery isolator or maintainer.. I do have an "Aux Start" but I assume that would be through the inverter/charger.

Mine (97) was mounted in the rear electrical panel in the engine bay.

They are the bottom two components in this pic:


I also removed my big "boost" solenoid that provides the ability to temporarily connect the LiFeP04 to the chassis if they go dead, but that was optional.