Our custom Lithium battery installation

[jkuang]

Originally Posted by RF Paul

I’ve been reading this and other lithium-related threads in search of an answer to the question: What does ‘lithium-ready’ really mean? I’m working on a build sheet for a 5.0, with a completion date of June 2023. I can’t decide whether to order lithium-ready and purchase a battery separately, or bite the bullet and pay what seems like a lot of dough for the ETI installed batteries. The big determining factor for me is how much re-wiring, and how many other components (shunts, fuses, monitors) I would have to install along with the battery if I go with the lithium-ready option. I’m fairly handy, but not very electrically savvy. I was hoping that with lithium-ready I can just unhook and take out the lead acid battery and install and reconnect the cables to my new lithium battery. Is that wishful thinking? I plan to also get two solar panels installed along with the 1500 watt inverter and electrical management system with surge protector.

Hi RF Paul,

I am in the same situation, I have a completion date in mid of July, 2023 for a 5.0.

As far as I understand, with solar panels + lithium ready + inverter options, I will have a Victron shunt battery monitor (shunt and monitor). I am not sure about fuse, I am going to ask ETI. I think if I replace the stock lead-acid battery with one lithium battery, I can just take the lead-acid battery out and drop in the lithium battery in the same battery box (my new CHINS Li battery will fit), and re-connect the wires. If I want to have 2 lithium batteries, then I have to build more hardware to fix the 2nd lithium battery to the floor and more and longer wirings.

Other than these hardware change, I think the stock WFCO power convertor will recognize the new Li battery and adjust the charging profile accordingly. The Victron solar controller will need some adjusting (through software interface) to the appropriate charge profile for the battery of your choice.

Have you get the chance to talk to ETI? Let us know what they say. Thanks.

[jkuang]

Originally Posted by splitting_lanes

You’ll need to add the shunt and the t-class fuse as I did, unless they’ve changed.

You’ll probably want to replace the battery disconnect switch and shorten the wiring too.

Adding a switch to be able to turn off the solar panels is nice so you can easily disable charging in below freezing temperatures.

Hi Splitting Lanes,

I don't quite understand the reason you move the switch. My understanding is that you move the switch to the solar panel so that you can switch solar off when needed. But I thought the switch is there to dis-connect the battery from everything connected to it, by moving the switch to solar you cannot disconnect the battery from others. Do i understand wrong?

[John in Santa Cruz]

Originally Posted by jkuang

Hi Splitting Lanes,

I don't quite understand the reason you move the switch. My understand is that you move the switch to the solar panel so that you can switch solar off when needed. But I thought the switch is there to dis-connect the battery from everything connected to it, by moving the switch to solar you cannot disconnect the battery from others. Do i understand wrong?

no, you add another switch to disconnect the solar panels from the solar controller. I put this switch on my main panel under the bench seats near the solar controller, as the only time I need to flip it is when I'm going to be doing wiring.



(batteries are just off screen to the left)

[splitting_lanes]

Originally Posted by jkuang

Hi Splitting Lanes,

I don't quite understand the reason you move the switch. My understanding is that you move the switch to the solar panel so that you can switch solar off when needed. But I thought the switch is there to dis-connect the battery from everything connected to it, by moving the switch to solar you cannot disconnect the battery from others. Do i understand wrong?

I moved the switch to shorten the wiring and make it easier to access. It’s not easy to get under the rear seat in a u-shaped dinette.

I also added a second switch to be able to turn off the solar panel, as John said. It’s nice to be able to turn off the solar when your trailer is in storage between trips, sometimes.

[John in Santa Cruz]

Originally Posted by splitting_lanes

I moved the switch to shorten the wiring and make it easier to access. It’s not easy to get under the rear seat in a u-shaped dinette.

I also added a second switch to be able to turn off the solar panel, as John said. It’s nice to be able to turn off the solar when your trailer is in storage between trips, sometimes.

I turn it off with the Victron Connect Bluetooth app for those sorts of reasons.... The solar switch is just for when I disconnect the batteries.

[Telescopist]

Originally Posted by splitting_lanes

LiFePO4 batteries that we install in the trailers are not prone to run away fires like lithium batteries in cars. The PO4 part makes the batteries very stable.

Just for perspective and these are quoted. "AutoInsuranceEZ found that for every 100,000 EVs, there are about 25 fires each year. That compares to 1,530 car fires in the same number of gas-powered vehicles annually. Gas-powered cars typically catch fire due to fuel leaks or crashes".

And, "Electric vehicles are not more likely than gas-powered cars to catch fire in crashes. Tesla, which makes more than half of the electric vehicles sold in the U.S., reports five car fires per billion miles driven, compared with 55 fires per billion miles driven in gas-powered cars."

And then there is probably a plethora of statistics which claim the opposite if anyone has a desire to refute.

[John in Santa Cruz]

Otoh, electric vehicle lithium battery fires tend to be much harder to put out... Also highly toxic.

[Telescopist]

Originally Posted by John in Santa Cruz

Otoh, electric vehicle lithium battery fires tend to be much harder to put out... Also highly toxic.

It's a good thing these fires are extremely rare events.

[JohnK]

Fist of all thank you to Jon Vermilye and Rick (splitting lanes) for your advice and suggestions.

As much for further critique and suggestions as anything, I'll post my installation of our 230 amp hour battery which I purchased during Li Time's current Black Firiday sale for $659 tax and shipping included. I believe this same battery can be had now for approximately $40 less.

Rationale for this battery was: 1) our 127 lbs combined 6 volt factory batteries are 4 years old and we anticipate close to a month of winter boondocking in February, 2) we purchased this battery with the future in mind such as possibly a compressor fridge, and 3) Li Time's Black Friday sale seemed to be a good opportunity. Incidentally, weight savings with this battery weighing 45 lbs is 82 lbs. I gave the two six votlt lead acids to a friend with spina bifida for use on his golf cart.

The tray is 3/4 inch interior finish plywood lined with 1/2 inch aluminum angle tacked onto the floor with ten 1 1/4 inch wood screws. You'll recognize the old battery box hold down hardware. The battery is 19 inches long and mounted lengthwise fore and aft. I had to buy a new and longer battery cable for the positive side. Hard to believe i could not find a red one. I found out one has to be 75 years old to believe that black is for negative and red is for positive. Oh well.

After the installation I boondocked two days and nights using more than our normal nighttime power usage. Each morning I found the battery at 100% / 13.3 volts as indicated by the PWM 30 UL. Voltage readings taken at the battery terminals are within 1/10 of a volt as indicated by the PWM 30 UL. I found I can easily replace the amount of power we typically use overnight with our single rooftop 190 watt panel. Just for grins I've also got a 100 watt portable panel to augment the rooftop panel. I'll buy a LiFePO4 battery charger for backup if we ever need that. Otherwise for this season I'll stick with our currently installed charging equipment.

Since I got home with the battery reading 14+ volts and 100% on the PWM controller, I am in the process of bringing the battery down to the recommended 50 - 60% per storage. This has required several hours of running the fridge on DC as well as about 45 minutes of running our cube heater at the 700 watt setting off the inverter. I'm currently letting the battery stabilize for 24 hours for a final reading prior to taking the battery out of the trailer for 6 weeks of strorage.

Thanks for all the good information on this thread. You won't offend me with further advice and suggestions.

John

[rubicon327]

Originally Posted by JohnK

You won't offend me with further advice and suggestions.

John: Nice install. Sounds like it is working well. My only comment for consideration is that your Go Power PMW-30-UL solar controller charge percentage is likely not very accurate as far as a true state of charge for a LiFePo battery. It is likely just using voltage which may be ok for lead acid but not so much for lithium. If you really want to know what is going on with the battery I recommend a Victron BMV-712 monitor or equivalent. If you don't mind reading off your phone then you can just get away with the more affordable SmartShunt. Personally, I like the display. Truly like a "gas gauge" and knows exactly how many amps have been put in and taken out of the battery.

[JohnK]

Thanks Rubicon for the shunt suggestion. Rick has mentioned to me the same about needing a shunt and the unreliability of the GP PWM unit for determining SOC. I will do something about that prior to boondocking this winter, but just for now I am backing it up manually from volt meter readings at the terminals and the SOC chart in the battery manual. Other than needing to be in the SOC range of 50-60% for storage, our current usage habit pattern does not come anywhere close to taxing the capacity of this battery.

John

[rubicon327]

Originally Posted by JohnK

Thanks Rubicon for the shunt suggestion. Rick has mentioned to me the same about needing a shunt and the unreliability of the GP PWM unit for determining SOC. I will do something about that prior to boondocking this winter, but just for now I am backing it up manually from volt meter readings at the terminals and the SOC chart in the battery manual. Other than needing to be in the SOC range of 50-60% for storage, our current usage habit pattern does not come anywhere close to taxing the capacity of this battery.

John

Understood. That is a great explanation provided by the battery manufacturer for a rough estimate of SOC. I understand that some may be ok with that level of accuracy. Forgive me as I'm on the other end of the spectrum because if I'm running my 9,000 BTU mini-split A/C all night off the inverter I want to have a pretty exact indication of where I'm at in the morning. I have both a Victron BMV-712 and shunt-based AiLi battery monitor built-in to our Bestgo 400AH battery. They continue to read pretty close since manually synchronizing the BMV which is nice.

[Telescopist]

Originally Posted by rubicon327

Understood. That is a great explanation provided by the battery manufacturer for a rough estimate of SOC. I understand that some may be ok with that level of accuracy. Forgive me as I'm on the other end of the spectrum because if I'm running my 9,000 BTU mini-split A/C all night off the inverter I want to have a pretty exact indication of where I'm at in the morning. I have both a Victron BMV-712 and shunt-based AiLi battery monitor built-in to our Bestgo 400AH battery. They continue to read pretty close since manually synchronizing the BMV which is nice.

I'm happy with the the performance of the AiLi battery monitor which is @$41 vs $186 for the Victron (in the AMZN world).