Lithium vs lead acid

[Oregon_Camper]

What is the reasoning for the Alliance to have the DC/DC charger for the disc brakes when other trailers do not have a DC/Dc charger with disc brakes? I am not at all doubting you, but my Paradigm had disc brakes and did not have a DC/DC charger in it either. Maybe it is a newer thing, but my 22 SOB doesn't have a DC/DC charger for the disc brakes, either.

Just a guess, but based on the year of your prior Alliance, you had a 120v or 120v/Propane frig...right? With the new models (like our 2023 340RL) they come with a 12v frig. This frig plus the draw of the disc brakes, most likely forced Alliance to add a method to add power to the battery bank. You can't always count on solar, as someone could be driving in the dark or low performance on overcast days.

 

[BryanValRox]

What is the reasoning for the Alliance to have the DC/DC charger for the disc brakes when other trailers do not have a DC/Dc charger with disc brakes? I am not at all doubting you, but my Paradigm had disc brakes and did not have a DC/DC charger in it either. Maybe it is a newer thing, but my 22 SOB doesn't have a DC/DC charger for the disc brakes, either.

Hi Darrell, no worries , we are just having good old constructive conversation.
I listed two of the reasons that I can think of in my other post, I guess the electrical engineering department at Alliance would be able to share why they chose this route. @Oregon_Camper comments as well about the demands.
I totally get that in theory that it is not required to make things work and the truck charge line would input to the battery regardless without a DC/DC.
I really think that the main reason is related to battery longevity(health) by providing a sensed and control output to the coach independent of the tow vehicle , and to prevent any 12 volt drain from impacting the tow vehicle given the extra draw of the12 volt frig.
The unit acts as an isolator and will not pass current unless the trigger wire is activated.
Only a guess, but imagine a seniero , where the unit is parked, still hooked up, not plugged into shore power, but having a need to power the frig.
In theory, you could drain the truck battery and not be able to start(without this isolator functionality).
Just offering my .02.
Maybe the A Team could provide more clarity on their strategy.
Best regards,
Bryan

 

[darrell]

Just a guess, but based on the year of your prior Alliance, you had a 120v or 120v/Propane frig...right? With the new models (like our 2023 340RL) they come with a 12v frig. This frig plus the draw of the disc brakes, most likely forced Alliance to add a method to add power to the battery bank. You can't always count on solar, as someone could be driving in the dark or low performance on overcast days.

I had a residential fridge. But thinking about your post, my residential fridge running off the inverter put a higher load on the 12v system than the 12v/propane fridge would. I did not have any solar.

 

[Fishfnatic]

I was talking to somebody who had an alliance paradigm trailer and he said he had to install switch to turn off 12 volt so he had trailer brakes. He said his truck sensed the 13 volt coming from solar and 12 volit would not activate brakes. Once he did that his trailer brakes worked every time. He had a 2023 that did not have solar cutoff switch.

 

[darrell]

Hi Darrell, no worries , we are just having good old constructive conversation.
I listed two of the reasons that I can think of in my other post, I guess the electrical engineering department at Alliance would be able to share why they chose this route. @Oregon_Camper comments as well about the demands.
I totally get that in theory that it is not required to make things work and the truck charge line would input to the battery regardless without a DC/DC.
I really think that the main reason is related to battery longevity(health) by providing a sensed and control output to the coach independent of the tow vehicle , and to prevent any 12 volt drain from impacting the tow vehicle given the extra draw of the12 volt frig.
The unit acts as an isolator and will not pass current unless the trigger wire is activated.
Only a guess, but imagine a seniero , where the unit is parked, still hooked up, not plugged into shore power, but having a need to power the frig.
In theory, you could drain the truck battery and not be able to start(without this isolator functionality).
Just offering my .02.
Maybe the A Team could provide more clarity on their strategy.
Best regards,
Bryan

Ok, so it is not necessarily because the disc brakes require a DC/DC converter. I was jut completely confused as to why that would be the case since they have been working for years without them. If they are doing that for other reasons, more power to them. but using a DC/DC converter at the end of the 7-pin connector won't buy you much, certainly not any more charge than the 7-pin itself is providing. It can certainly pull power from the 7-pin if the truck itself doesn't have a relay that disabled the 12v feed when the truck is not running. I cannot honestly say I have test the 12v+ pin to see if the truck pushes power without the truck running. I will do so when I get a chance, though.

 

[darrell]

Another oddity, though, is my current trailer also has disc brakes and no DC/DC charger, but it does have solar on it that runs all the time. I do not have the issue that @Fishfnatic mentioned with that trailer. Maybe they have changed something with the Hydrastars I have had that are newer. I am just trying to understand the need. As @BryanValRox said, maybe the Alliance engineers found something others haven't. I would like to know the reasoning more than ever now.

 

[darrell]

I was talking to somebody who had an alliance paradigm trailer and he said he had to install switch to turn off 12 volt so he had trailer brakes. He said his truck sensed the 13 volt coming from solar and 12 volit would not activate brakes. Once he did that his trailer brakes worked every time. He had a 2023 that did not have solar cutoff switch.

I think they are some trucks that have an incompatibility with the OEM brake controller, but I don't think this would be it. I could be wrong, though.

 

[BryanValRox]

Hi Darrell,
In the what it worths department .
My 2014 Ford F-150 has a “switched” charge line. Ignition base, key on output, key off no output
My 2024 Ram 3500 has a unswitched charge line, terminal is hot all the time regardless of key position or time with no activity.

 

[darrell]

Hi Darrell,
In the what it worths department .
My 2014 Ford F-150 has a “switched” charge line. Ignition base, key on output, key off no output
My 2024 Ram 3500 has a unswitched charge line, terminal is hot all the time regardless of key position or time with no activity.

I feel like my 2021 Ram 3500 is the same, unswitched. But I cannot say I have actually tested it. I think the USB ports can have the fuse switched places so the USB remains hot all the time, but I don't think F30 on mine allows that. It is either populated or not.

 

[Dan54]

Scanning YouTube for more info on lithium batteries I ran across a video by Emily & Clark’s Adventures that stated a lithium battery can burn up an alternator. He says that lithium batteries have a built in battery management system that shuts off the current coming from the alternator when the battery is fully charged. In an instant the current having nowhere to go the alternator gets smoked along with possibly/probably other connected devices. I think he said this has to do with the fact that lithium batteries can accept a charge so much faster causing the alternator to be a max power when the shut off occurs. His example was for boating & a significantly discharged battery but I wonder if any damage could be done to my trucks alternators when hooked to a trailer with lithium batteries? As I am writing this I am thinking probably not because my truck has 2 lead acid batteries that will be accepting charge.

 

[Oregon_Camper]

Scanning YouTube for more info on lithium batteries I ran across a video by Emily & Clark’s Adventures that stated a lithium battery can burn up an alternator. He says that lithium batteries have a built in battery management system that shuts off the current coming from the alternator when the battery is fully charged. In an instant the current having nowhere to go the alternator gets smoked along with possibly/probably other connected devices. I think he said this has to do with the fact that lithium batteries can accept a charge so much faster causing the alternator to be a max power when the shut off occurs. His example was for boating & a significantly discharged battery but I wonder if any damage could be done to my trucks alternators when hooked to a trailer with lithium batteries? As I am writing this I am thinking probably not because my truck has 2 lead acid batteries that will be accepting charge.

IMHO...I think you're over thinking this. These devices are smart/aware of the battery type you have and understand to slow down the charge as they approach fully charge. Think of it like this...if you rode in an elevator to the 100th floor...it would rocket up to the 85th floor and then begin to slow down at it approach the 100th floor....same for todays intellgent lithium batteries with a BMS. Back to truck...a properly installed DC-to-DC charger will have a properly matched fuse, just off the battery. If anything where to go wrong, you would simply have to replace your fuse.

 

[BryanValRox]

Jim,@Oregon_Camper ,
I agree with your explanation and thank you for the simplicity of your explanation.
I was going to post about alternator theory, voltage sensing and voltage regulators within the alternator.
But, your elevator analogy certainly helps simplify things.
Folks fail to realize that just because a alternator is capable of x output, it doesn’t mean that it is always out putting the maximum rate.
I personally enjoy the amount of knowledge that everyone has and shares on this forum!
Best regards to all!

 

[Dan54]

Thanks for your response. IMHO I am not overthinking anything. I am trying to educate myself on a subject that is new to me by reading, watching videos & asking questions. My questions may seem uninformed & that’s because in this area I am uninformed. And trying to become more informed as I move forward with a new trailer which is much more technologically advanced. Thanks for taking the time to help me do so.

 

[darrell]

Scanning YouTube for more info on lithium batteries I ran across a video by Emily & Clark’s Adventures that stated a lithium battery can burn up an alternator. He says that lithium batteries have a built in battery management system that shuts off the current coming from the alternator when the battery is fully charged. In an instant the current having nowhere to go the alternator gets smoked along with possibly/probably other connected devices. I think he said this has to do with the fact that lithium batteries can accept a charge so much faster causing the alternator to be a max power when the shut off occurs. His example was for boating & a significantly discharged battery but I wonder if any damage could be done to my trucks alternators when hooked to a trailer with lithium batteries? As I am writing this I am thinking probably not because my truck has 2 lead acid batteries that will be accepting charge.

The 7-pin wiring will not allow you to overrun your alternator. In fact, I have never actual heard of or seen anyone damage an alternator, even in a motorhome, by using it to charge a LFP battery. Victron has a video of it happening, but they deliberately created an environment that would not happen in the real world.