Replacing 2 Lead Acid Batteries with one 12V 230AH Lithium battery.

[Mike Rod]

I have a 2021 Jayco 321 RSTS 5th wheel RV. Came with 200W GO Power panel on Roof, 1200W Sine Wave inverter, The PD4560K18NS2B Convertor with 13.6 VDC. 60A Output, and 2 Lead Acid batteries.
My tow vehicle is a 2023 Ford F350.
The batteries are 3 years old and I want to replace them with one 12V 230AH Lithium battery.
I will be using the battery and solar to keep the 120V residential refrigerator running while trave to the next RV resort no more than 6 hours away.
What upgrade do I need to do to make sure I charge this battery correctly?

Thank you,
Mike Rodriguez
cmikerod@yahoo.com
920-216-0540

 

[MisterSandals]

What upgrade do I need to do to make sure I charge this battery correctly?

I upgraded from 2x lead acid 100Ah batteries to a 412Ah LiFePO4 battery 3 years ago. I have the same but smaller PD4645 ? unit. Works just fine. I think it charges to about 90% but not sure because i almost always use solar.

What charge controller do you have? Is it lithium aware or have a user defined battery setting? This will help keep your battery charged.

Do you have any idea how much power your refrigerator and inverter use each hour? With this we could determine how long your battery can power it and how much solar can help.

 

[Gason]

Charging depends on the charger and inverter support lithium iron, 13.6V seems a bit low.

 

[pollenface]

I have a 2021 Jayco 321 RSTS 5th wheel RV. Came with 200W GO Power panel on Roof, 1200W Sine Wave inverter, The PD4560K18NS2B Convertor with 13.6 VDC. 60A Output, and 2 Lead Acid batteries.

What upgrade do I need to do to make sure I charge this battery correctly?

What is the 13.6v converter for?

Use an MPPT that can be configured sufficiently for your new LFP battery.

A Victron Smartsolar 75/15 & Victron Battery Sense (for low temp cut off) is my recommendation.

 

[Mike Rod]

Thank you. I will look into it.

 

[mikefitz]

What upgrade do I need to do to make sure I charge this battery correctly?

The converter charging at 13.6 volts, whilst not ideal, will charge the battery up to around 80%, and higher given enough time.
The solar will top up and generate enough charge volts for the BMS balance to function. Recomend changing the solar charge controler to MPPT type, Victron Smart 75/15 further existing 200 watts of solar. A future update adding a similar 200 panel would be useful. This would need a Victron 10/30 controler.

 

[Solarcabin Channel]

As mikefitz stated the 13.6 volt converter won't completely recharge an LFP that takes 14.6 volts.

Look on Amazon:

Progressive Dynamics PD9160ALV 12V Lithium Ion Battery Converter/Charger - 60 Amp​

PD9100L Series 12V Lithium Ion Battery Converter/Chargers provide a Constant Current/Constant Voltage (CC/CV) charge profile as recommended by lithium battery manufacturers. PD9100L Series units can be connected both in parallel and in series. Reverse battery protection prevents charger damage if the battery connections are accidentally reversed. Filtered DC power ensures proper lithium Battery Management System (BMS) operation. Electronic Current Limiting automatically reduced output voltage to prevent overheating and possible damage. High and Low Voltage Protection prevents charger damage from AC input voltage fluctuations. Automatic Thermal Protection reduces charger output to safe levels if unit temperature exceeds safe levels pre-set limits and protects charger damage due to excessive heat. An intelligent cooling fan operates only under high load conditions. Input Voltage: 105-130 VAC 50/60 Hz 1025 Watts. Output Voltage: 14. 6 VDC 60 Amps.

 

[mikefitz]

PD9100L Series 12V Lithium Ion Battery Converter/Chargers provide a Constant Current/Constant Voltage (CC/CV) charge profile as recommended by lithium battery

In practice 14.6 volts requires a battery with perfectly balanced cells. As this is rarely the case with low cost batteries as BMS shutdown due to cell inbalanse may cause unwanted issues. Charging to a lower voltage like the Victron default for lithium at 14.2 volts is a safer and less stressful technique. Any voltage over 13.8 will charge the battery to over 99%.