Dropping in Lithium Batteries

[Kickythekick]

Hello,
I know I am likely asking something that has been answered 1000 times but after all the research I've done (paired with my lack of experience) I just want to make sure I'm correct in my understanding...

I purchased two of the Lion Safari UT 1300 batteries from Costco: https://lionenergy.com/products/lion-safari-ut-1300

I have a 2015 27fb International and know that I need to update the OEM charger to properly charge the batteries. That said, if I just simply remove my 2 current lead acid and replace them with these Lithium batteries, what would happen? Will they still work but not operate at the highest level of efficiency? I have seen posts saying that they will only charge to 80% but I also want to make sure I'm not going to start a fire or anything.

My goal this summer is to have a technician do the proper upgrade for me but until I can find someone I'd love to be enjoying some of this wonderful weather.

Thanks in advance!

[Peter417]

I would look at the battery manufacturers recommended charging voltage. Then look at the charger you have and see what the max voltage charge is.



Your probably fine. It will probably be more like 70%.

[wilsodf]

We installed a Progressive Dynamics 4655VL that has the ability to charge a Lithium Battery. Also, if your not installing a DC-DC charger, I would pull the fuse in your tow vehicle that supplies power to the 7-way when towing.

[uncle_bob]

Hi

To properly go into the "equalize" phase of the charge cycle, the BMS in your lithium batteries needs to get > 14.4V from the charger. If it does not see that voltage, it will not balance out the cells. If the cells are not balanced, some will / may / might be working way to hard. That will shorten their lifespan. In an extreme case you could have an outright failure of the battery.

Since there is absolutely no way to know how well things are balanced at any one time, there is no way to predict just how bad / just how quick this all gets. Simple answer is to put the correct charger on them.

The "stock" converter / chargers struggle to get to 13.2V. There is a lot of variability model to model and unit to unit. Some will make it to 13.6V. Unfortunately that difference has a very big impact on Lithium batteries. At 13.6, you likely are close to full capacity. At 13.2 you could easily be 30% low. Again another reason to upgrade the converter.

Next up is the charge wire on the 7 pin adapter. If you leave it in place, your nice new lithiums will play games with the lead acid's in your tow vehicle. The result will not be good. The lithiums likely will drain into the truck electrical system.

None of this is crazy hard to do. It *is* part of the process.

Bob

[Peter417]

Bob are you sure this battery does not have a built in bms that keeps the cells equalized? I believe battle born does this. That is what the tech I spoke to said. Maybe I did not understand correctly.

[rfequity1]

So then, what is the recommendation for the "charge wire" on the 7 pin? If I am not concerned with charging while I drive can I just remove it as Bob said?

[Kickythekick]

Thank you all so much for your responses!

so, to reiterate...

1. It won't hurt to at least give it a shot, especially if it's just a short term thing for a few months

2. I should contact Lion Energy to see if the BMS will balance.

3. I will hook up the batteries exactly like I have my current batteries hooked up

4. I will remove the fuse from my TV that supplies the 7-pin.

If I remove the fuse... do the trailer brake lights and such still work?

Thanks again!

[uncle_bob]

Originally Posted by Peter417

Bob are you sure this battery does not have a built in bms that keeps the cells equalized? I believe battle born does this. That is what the tech I spoke to said. Maybe I did not understand correctly.

Hi

I'm quite sure they have a BMS. Is it exactly the same as this one or that one? Who knows.

Pretty much all BMS setups ( including Battle Born ) only do equalization at the *end* of the charge cycle. The do not do any of that the rest of the time. This turns out to be easier to implement in a reliable fashion. It also keeps a parasitic load out of the picture *except* when you are sure there is plenty of power to run the equalization process.

This "only equalize at the end" is why running lithiums below full charge 100% of the time is not a great idea.

Bob

[Peter417]

After further research, my battery requires anything between 14.2 and 14.6 to balance. it looks like a battery charger capable of charging agm batteries should allow a lithium to balance. I use the charge wizard on my intelipower 9100. Pushing the button upps the voltage to 14.4.



I also wonder how often these batteries need to be balanced.



One final thought, I have an intact TV charge circuit. I would guess that my truck is older than most but I have no ill effects with a lithium battery in the circuit.

[uncle_bob]

Hi

Not all lead acid chargers get up above 14.2V. There are some that zoom of to > 18V so, no way to really be sure. I would not want to depend on a lead acid charger doing the right thing unless I'd actually checked it out. ( You do *not* want one that heads above 14.8 doing some sort of lead acid rejuvenation process ....).

There's no way to really know how often a stack needs to be balanced. A lot depends on how well the internal bits were matched up and how well that matching holds over time. Back when I knew folks in the battery pack business, the answer was "not so much" in terms of the matching holding up over time. That was a while back ....

Common wisdom is that you could hit the balance once a week and be fine. Once a month probably is fine. Once a year ... not so much. Just what that's based on is abundantly unclear. ( doing a full cycle once a day just might impact this sort of stuff ....)

Bob

[TKCamper]

Originally Posted by wilsodf

We installed a Progressive Dynamics 4655VL that has the ability to charge a Lithium Battery. Also, if your not installing a DC-DC charger, I would pull the fuse in your tow vehicle that supplies power to the 7-way when towing.

There is no need to pull the fuse on your tow vehicle. The wire size that is used to carry the voltage will not be large enough to harm your alternator. When towing, only 7-8 amps are being sent to my lithium batteries. To get the most if your alternator you will need 4-0 wire and then yes a DC to DC charger will be needed.

[JonDNC]

Originally Posted by TKCamper

There is no need to pull the fuse on your tow vehicle. The wire size that is used to carry the voltage will not be large enough to harm your alternator. When towing, only 7-8 amps are being sent to my lithium batteries. To get the most if your alternator you will need 4-0 wire and then yes a DC to DC charger will be needed.

I have not pulled the wire either, the batteries are being charged by solar even while driving, this just adds a little more.

[uncle_bob]

Hi

Your vehicle electrical system is *not* set up to maintain 14.6V at all times. As soon as you pull up to a stop light, the engine and alternator slow down. At that point the fully charged lithium's in your trailer will do their best to supply all the truck's electrical needs.

Since the battery should / could / might be up around 14.x volts and your truck alternator might be out of the picture at idle. Net result is a fight between the (maybe) 40AH battery in the TV and the (maybe) 400AH in the trailer. Even with a long wire, the Lithiums are going to "win" this one and supply quite a bit of current.

Will this damage the lithiums? Nope. Will it damage the TV? It won't do the battery any good, beyond that nope. Will it discharge the lithiums so that you end the day with less charge in them than you started with? There are a *lot* of threads where folks answer that one with a great big YES.

Bob