Battleborn in trailer overcharging my tow vehicle battery via 7 pin?

[bshackcreative]

I have one Battleborn 100ah battery in my travel trailer. It charges while being towed via a 7pin. My tow vehicle is a 2020 Tundra with a flooded battery. The battery in my truck is 2.5 years old.

I’m seeing some signs of corrosion on my truck battery. It almost like it pooled on the top a little. Also some around the terminals.

When towing all day.. like 8 hours.. am I overcharging my battery because of the trailer battleborn battery? Is that even a risk?

Or do I just need a new truck battery because it is starting to fail?

 

[Bobert]

I doubt your lifepo4 is overcharging your truck battery. Resting voltage of your battleborn battery is way below the normal charging voltage of a lead acid battery. I would clean the battery with baking powder and water corrosion is a normal thing with lead acid batteries especially in hot weather and 2.5 years of off gassing. You should get 3 to 5 years out of a good gently treated battery (not flattened repeatedly)

 

[NVS]

If you are using a DC-DC charger this also acts as a isolator to keep that from happening.

 

[bshackcreative]

If you are using a DC-DC charger this also acts as a isolator to keep that from happening.

If I install a DC DC charger on my 7 Pin will the rest of my trailer devices using the 7pin power go uninterrupted? Or need any additional wiring changes besides putting the DC DC in line of the trailer power? I’m thinking about the emergency breakaway cable safety system? Or will it all still work as expected?

 

[Bobert]

If I install a DC DC charger on my 7 Pin will the rest of my trailer devices using the 7pin power go uninterrupted? Or need any additional wiring changes besides putting the DC DC in line of the trailer power? I’m thinking about the emergency breakaway cable safety system? Or will it all still work as expected?

A dc to dc charger goes in your trailer and is fed by the wire from yor 7 pin or if you choose a larger separate set of wires for faster charging it won’t affect your 7 pin connector or brakes or breakaway switch.

 

[NVS]

Put the DC-DC charger will connect to the charge wire and ground. The rest of your lights will work as usual. Several people have wran a wire straight from Tow Vehicle battery to the trailer with 6 or 8 gauge wire so they can charge at 40 amps.

 

[Bobert]

Several people have wran a wire straight from Tow Vehicle battery to the trailer with 6 or 8 gauge wire so they can charge at 40 amps.

If you do that be sure your alternator can handle the extra load.

 

[RVLiFe]

I simply found the fuse to the Aux on the 7-pin and pulled it. I don't think its wise to keep two different battery technologies connected this way. I do believe it could be causing issues to your main vehicle battery. DC-DC charger would be the correct device to use if you really need to charge from your vehicles alternator.

 

[Checkthisout]

I have one Battleborn 100ah battery in my travel trailer. It charges while being towed via a 7pin. My tow vehicle is a 2020 Tundra with a flooded battery. The battery in my truck is 2.5 years old.

I’m seeing some signs of corrosion on my truck battery. It almost like it pooled on the top a little. Also some around the terminals.

When towing all day.. like 8 hours.. am I overcharging my battery because of the trailer battleborn battery? Is that even a risk?

Or do I just need a new truck battery because it is starting to fail?

Well, just clean the terminals and top of battery and load test. Batteries aren't perfect and can develop tiny leaks that are of no consequence so long as the top of the battery and terminals are kept clean.

And no, the battery in the trailer is being charged by your truck and will always be a lower voltage than what your truck is supplying.

 

[brb58]

There have been many cases of LiFePO4 overcharging lead acid batteries in tow vehicles, especially lithium batteries that also have solar charging them. Use a DC to DC converter between the tow vehicle and the lithium batteries

 

[Checkthisout]

There have been many cases of LiFePO4 overcharging lead acid batteries in tow vehicles, especially lithium batteries that also have solar charging them. Use a DC to DC converter between the tow vehicle and the lithium batteries

If there is a solar system then maybe.

If not, how and why would that happen?

 

[brb58]

If there is a solar system then maybe.

If not, how and why would that happen?

Yes, it would likely only happen when there was a solar system attached.

 

[time2roll]

Check the voltage on your chassis battery terminals. Check initially and after an hour continuous drive. Take notes. Post the results.

 

[HRTKD]

The truck should be smart enough to not allow the trailer to send a charge back to the truck.

A corroded battery is a yellow flag that your battery may be reaching its end of life. Check the electrolyte levels.

Installing a DC-DC charger has to be carefully planned. If you do it wrong, the trailer's breakaway system will not have power.

I took a different approach than RVLife did. My LiFePO4 battery bank is completely isolated from the charge circuit provided by the tow vehicle. It gets no charge at all from the tow vehicle. My PV system provides plenty of charge. I have a small lead acid battery on the tongue that is connected to the 7-pin circuit and the trailer's breakaway system. The lead acid battery is isolated from the rest of the trailer and has its own solar panel for maintaining a charge.