Industry Looking for Lithium Battery Replacement

[Tom Traveler]

See I've already made a faux pas by lumping Lithium-ion together with Lithium-ion phosphate type batteries in relation to talking about RVs.

I'm getting to the age where I need to forget something in order to remember something new! (saying loosely borrowed from the movie Lone Star)

Same here. I tell people the hard drive is full and I need to erase a few files to add new ones.

[Riverbug]

I went down the same rabbit hole, just deeper. I installed two 304ah batteries in 2022 and I am in the process of installing two more. That should give me at least 1200ah.

Last week, I replumbed the mess behind the Nautilus panel. Moved a lot of the wiring and found just enough room to install the other two. One advantage of a DIY approach, you can tetras these batteries to any shape you need to fill the void.

The prices seemed to be a bit lower than a couple years ago as mentioned.

LOL....it's OK. Prior to me wanting to either buy or build a LiFePO battery, I knew absolutely ZERO about them. When I started looking at the cost for a LFP battery that was in the 300AH or so range, I decided to see what it would take for me to purchase cells, a BMS, and whatever else was required and build one myself. I went down the "rabbit hole" fairly deep and finally decided to build one ....a DIY project. That was late 2021 and back then the pricing was significant between an already built battery from a manufacturer vs. building one yourself. I'm 100% happy with the way mine turned out, but fast forward to the current prices of today and the somewhat steady drop in pricing on the already built.......and that comparison on pricing is much closer now. I'm still happy that I did it though and I know exactly what I have, and the build quality that is there.

I also went down that rabbit hole and built 4 280AH LiFePO4 packs for 13.4KW of capacity. I recently did another comparison of buy vs build to see how close they are. As the pre-built batteries get better and their prices come down, so have the EVE cells that we buy to make our own. When I purchased mine they were $150 for each 280AH cell. Now I see I can buy the same ones for $100. I paid $100 for each of my BMS' at the time and can now purchase the same BMS for $75. Cables and connectors are a different story though; they have gone up somewhat.

If I hadn't already purchased a 12V Victron Multiplus before I got too far into the project I would have gone 24V rather than 12V. But for comparison, you can buy a 12V 100AH Li Time battery for just over $300. You can now buy EVE 105AH cells for $40 each. So, $160 for cells, $75 for BMS, assume $40 for additional hardware and you're around $275. Then it just comes down to what you prefer but it's a toss up. I do enjoy building them and knowing exactly what is in them, but as the cheaper batteries are showing much more promise and have the basic features like low temp protection, as well as nice to have features like Bluetooth and some have the ability to set charging parameters, cell balancing, etc., I would very much consider buying vs building going forward. Maybe.

[SolarPoweredRV]

It took me awhile to understand the difference, but you will be replacing your LA battery with LiFePO4, not Lithium-ion. They are different batteries using different chemistry. LiFePO4 are inherently safer and, reportedly, won’t start on fire. Not the case with Lithium-ion. A speedster missed a curve locally and piled his Tesla into a tree. Luckily it was in a rural area outside of the city. The firefighters stood upwind and let it burn as a lithium-ion fire is very difficult to put out and the water just tends to spread the toxic material and fumes. They were left with a hazardous waste cleanup site.

I don’t know why cars don’t use LiFePO4 chemistry. Maybe because of lower energy density? That would be ah/size or ah/weight. Can someone weigh in with additional info?

Actually, cars do use Lithium Iron Phosphate (LiFePo4 [a.k.a. LFP]) batteries. As a matter of fact, Tesla has stated that ~ 50% of their cars are powered with LiFePo4 batteries.

The primary reason Lithium Ion batteries are used in EVs has to do with their energy density per kilogram. However, good LiFePo4 batteries have reached the same energy density as poor Lithium Ion batteries, consequently, there are several EVs available with LFP (LiFePo4) batteries. These EVs are generally the EVs with the lowest EPA estimated range, often referred to as the "Standard" range model.

It is also true that LFP batteries are safer because they are less likely to "self ignite". The reason Lithium Ion battery fires are so hard to extinguish is because as they burn, they generate their own Oxygen. They also generate an intense amount of heat, which in turn, ignites the battery cell next to the burning cell, causing a "thermal runaway" event. Additionally, Lithium Ion batteries in EVs tend to re-ignite even days after the initial fire has been extinguished.

[SolarPoweredRV]

https://www.bbc.com/future/article/2...hium-batteries

I figured I would start a new thread instead of attaching or high-jacking someone else's thread. I know a lot of you might say, Oh No, another thread on batteries, lets not do that. But I am still learning about all this new fangled technology !!

I know very little about Lithium-ion batteries that you all have been discussing, but I ran across this article off the BBC News. I just thought it was interesting. Industry is always looking for a better mouse trap. Battery technology and the fact that EVs are really taking off, not to mention all the other industries that use battery technology, I'm just trying to learn and stay in touch with new things. Solar as well.

We'll probably replace our 5 year old LA battery with a Lithium-ion, but I have to learn a lot more about them, and all the other things you guys and gals install with them.

First, the batteries used in RVs are Lithium Iron Phosphate (LiFePo4) batteries and not Lithium Ion batteries. LiFePo4 batteries (a.k.a.: LFP batteries) are a safer chemistry that is much less likely to catch fire.

There are several advantages to replacing your Lead Acid batteries with LiFePo4 batteries.

Here are a few:

With the new "Value Priced" LiFePo4 batteries, switching to Lithium batteries is on par with replacing Lead Acid batteries when you consider cost per usable amp hour.

LFP batteries weigh less and they have twice as much usable energy storage.

With LA, you generally do not want to discharge the battery below a 50% State of Charge (SOC). Consequently, you only have ~ 50ah "usable" from your 100ah LA battery. LFP batteries can be discharged to 0% SOC, making the full 100ah of the battery "usable" for your devices.

LFP batteries charge much quicker than LA batteries, saving you run time on your Generator if you are boondocking.

LiFePo4 batteries last much, much, longer, 4,000 discharge cycles, compared to ~400 for LA batteries.

LFP batteries maintain a higher voltage throughout their discharge cycle, this is better for all the electronics in your coach.

Here is a good thread to read up on LiFePo4 batteries and "All the other things you guys and gals install with them":

Affordable-Solar-How-To-Design-and-Install-an-Affordable-Solar-System

[SolarPoweredRV]

Same here. I tell people the hard drive is full and I need to erase a few files to add new ones.

The older I get, the more information that gets automatically erased.

[Butcher]

One benefit with a DIY is that you have probably researched into it and with that time spent, you can probably mix/match to get all the options you want. Depending on the person, the build quality is probably better too.

Not everyone is a DIY'er and there are some people better suited to buy an off the shelf product.

[Riverbug]

One benefit with a DIY is that you have probably researched into it and with that time spent, you can probably mix/match to get all the options you want. Depending on the person, the build quality is probably better too.

Not everyone is a DIY'er and there are some people better suited to buy an off the shelf product.

It definitely requires an investment in time to research and understand these things, especially with respect to testing the cells you receive and configuring the BMS parameters for optimal life cycle.

[Butcher]

It definitely requires an investment in time to research and understand these things.......

Easier than backing up your trailer in a tight campsite.

[kb0zke]

While helping a neighbor with his electrical problem, I moved his single LA battery. I've had LiFePO4 batteries for so long that I had forgotten how heavy a LA battery is. Yes, my 24V 200AH LiFePO4 batteries weigh 85 pounds each, but each one has four times the capacity as the 12V 100 AH ones they replaced, and they were half the weight of a similar LA battery. I still don't plan on moving my new batteries any time soon.