Why Wouldn't RV Converter/Charger Charge Lithium Batteries
Updated 11/17/2025 | Published 12/19/2024
Question:
Hello there I have a 2021 ATC toy hauler, I installed 2 new lithium 200 ah batteries connected in parallel. 12v . Each battery has its own bms within the battery itself. I cannot get my current converter to charge my batteries. I’ve included pics of me testing the converter with a multimeter. I am connected to the batteries and shore power when these tests were conducted. See pics. I purchased a new converter from you guys and am currently waiting for it to be delivered . Also , I have a switch near my front door that turns on and off all 12 v power so I understand that I need to remove the jumper and connect two pos conductors, one to each terminal .Currently, my wiring shows two conductors, one white and one black from the converter to the breakers , 14.56 v. . Then two red conductors to the top area , normally connected by the jumper, but removed per installation instructions for external 12 v disconnect switch by my front door. The bottom or lower red conductor shows no power only 1.351 vwhen tested against the neutral or white conductor, but gets 13.24 volts when tested against the upper red conductor. ??? It sounds like a ground or neutral connection also , there is a small yellow wire connected along with the lower red conductor’s terminal. Is this normal??? HELP TIA Alex
asked by: Alejandro
(click to enlarge)
Expert Reply:
Hey Alejandro, I don't see an order from you for a converter so I am not sure what you on the way but hopefully what you have is one that has a lithium charging profile. I would assume your current setup does not have a lithium profile and that's why you can't get your battery to charge. Let me know which converter you are getting and I'll let you know if it has a lithium profile. Most likely it does though as most of them in recent years had lithium profiles added.
Product Page this Question was Asked From
Progressive Dynamics 4500 Series RV Converter w/ Charge Wizard and AC/DC Distribution Panel - 60 Amp
- RV Power Converter
- Converter and AC/DC Panel
- Battery Mode Switch
- 12V
- 60 Amps
- AGM
- Gel
- Lead Acid
- Lithium
- Multi-Stage Charge
- Progressive Dynamics
more information >
Featured Help Information
Instructions
Continue Researching
- Q&A: Replacing American CS6000XL in Camper
- Q&A: Replacement Option for American Enterprises CS-6000XL Power Converter
- Q&A: Recommended AC/DC Distribution Panel And Charger For A 2006 Forest River Sierra Sport T34SP
- Q&A: Replacement Converter Recommendation For An American/Centurion CS6000 Converter
- Q&A: Replacement for Parallex 500 Series Model 555 Converter
- Q&A: WFCO WF-9960 Replacement Converter
- Q&A: Recommended Replacement Converter For A Parallax 7300 Series Power Center
- Article: Trailer Wiring Diagrams
- Article: 30-Amp and 50-Amp RV Service: What's the Difference?
- Article: Wiring Trailer Lights with a 7-Way Plug (It's Easier Than You Think)
- Article: How to Tell the Weight Rating of a Trailer Axle
- Article: How Does an RV Water Pump Work?
- Article: We Used 34 RV Tow Bars, and These are the Best for Flat Towing
- Article: How to Install a Weight Distribution Hitch (With Pictures & Video)
Jameson C.
11/17/2025
Hey Alejandro, did the new converter end up working with your lithium batteries in the ATC toy hauler? It’d be great to know if the lithium charging profile solved the issue. Your update could make it easier for others setting up a similar system.