Bare minimum required to upgrade to LiFePo4 batteries?

[qwertyd10n]

Hi all,

I've been pouring over the LiFePo4 related threads since determining that the original flooded batteries in the new-to-us 2019 International Signature 27FB we picked up last weekend are shot. The trailer had been sitting for quite some time and the original owner did not maintain the batteries and I cannot seem to recondition them to a usable state.

We did not expect to replace and upgrade the batteries right away, but we definitely like the tongue weight savings and overall longevity of LiFePo4 over regular flooded or AGM batteries.

That said, I haven't been able to completely wrap my head around exactly what equipment I'll need to upgrade in order to properly take care of the lithium batteries. I believe we'll need the following, but would love for someone to confirm this list:
- LiFePo4 batteries (obviously)
- a new inverter
- a current-based battery monitor system
- an upgraded AC-to-DC charger specific to lithium batteries
- a DC-to-DC charger to allow the lithium batteries to be charged by our TW while towing

I do not have any solar considerations right now and would like to leave the batteries in the battery box.

I realize there are many opinions on which gear is better or worse, so informed, first-hand experience with particular equipment makes and models would be appreciated.

Cheers,
Dion

[TRIPPPIN]

Lithium batteries should not be installed in the battery box due to the restriction they cannot be charged if below 0C. Converting to lithium is very expensive and if you are not installing solar or doing a lot of boondocking its a waste of money in my opinion. If your trips are to places where you can plug in save the money and just replace the batteries with 2 six volt AGM.

[JeffofCT]

Originally Posted by qwertyd10n

Hi all,

I've been pouring over the LiFePo4 related threads since determining that the original flooded batteries in the new-to-us 2019 International Signature 27FB we picked up last weekend are shot. The trailer had been sitting for quite some time and the original owner did not maintain the batteries and I cannot seem to recondition them to a usable state.

We did not expect to replace and upgrade the batteries right away, but we definitely like the tongue weight savings and overall longevity of LiFePo4 over regular flooded or AGM batteries.

That said, I haven't been able to completely wrap my head around exactly what equipment I'll need to upgrade in order to properly take care of the lithium batteries. I believe we'll need the following, but would love for someone to confirm this list:
- LiFePo4 batteries (obviously)
- a new inverter
- a current-based battery monitor system
- an upgraded AC-to-DC charger specific to lithium batteries
- a DC-to-DC charger to allow the lithium batteries to be charged by our TW while towing

I do not have any solar considerations right now and would like to leave the batteries in the battery box.

I realize there are many opinions on which gear is better or worse, so informed, first-hand experience with particular equipment makes and models would be appreciated.

Cheers,
Dion

Dion, I am evaluating the same thing. Seems like (I may be wrong) that many folks tend to buy two 100ah LION battery's because they're replacing two batteries which is probably giving 2-3x the ah reserve they're used to. Most people tend to use 30-50 ah/day without a lot of furnace/blower use and running the refrig on propane. My target is around 50-80ah/day.

We just purchased a 2011 Sport 22'. I had a 1 year old 110 ah AGM from my last trailer and it was an immediate upgrade to the single marine-style replacement battery. It is JUST adequate for our needs, provided we can get a generator on it 1-2 times per day. (BTW, we also use a 270w portable liOn generator and a smaller power brick which are recharged during generator time). Last dry camping spot (6 days) was completely shaded so could not use our portable solar. At the time, we did not have the Victron 712 installed, so I was just guessing on power needs and recharging times. This was a bit stressful on our maiden 6 day dry camping trip.

We're leaving Monday for a 5 day dry camping trip which will be our final evaluation before winter. With the Victron 712 now installed, I expect to get a really close accounting of our current power needs.

I have not decided on roof-mounted solar as the available real-estate is low on the sport 22. Most folks are putting 200-250w matched with 2 lion batteries. We have 220w portable and a 2000 Honda. Will update on our results here.

[ROBERT CROSS]

Originally Posted by TRIPPPIN

Lithium batteries should not be installed in the battery box due to the restriction they cannot be charged if below 0C. Converting to lithium is very expensive and if you are not installing solar or doing a lot of boondocking its a waste of money in my opinion. If your trips are to places where you can plug in save the money and just replace the batteries with 2 six volt AGM.

^
?

Not for our application.
Our two BB's have been stored year round in the OEM battery compartments.
If we use them and they need charging I've done so at 30* and above.
They can be isolated from everything but the Boondocker lithium charger.
The onboard BMS will stop charging when the ambient is below the limit.

Bob
🇺🇸

[kscherzi]

Trippin is right to consider what sort of camping you plan to do. Fully charged flooded wet cells (and AGM's) will easily last for a 3 day weekend. The kicker is furnace use because it's an electricity hog, but 10 minutes in the morning to take the edge off is fine. Your box will fit a pair group 27 batteries or a pair of deep cycle 6 volts, both at Costco in the $70/$80 range. Both have more storage capacity that the group 24's Airstream provides.

If you already carry a gas generator, you can camp indefinitely, just have to listen to that noise once in awhile.

That said the lithium's weigh less and hold a bigger charge. I think what you described above as parts plus a quality DC circuit breaker ($100) and wires and misc, will set you back I'm guessing close to $2500 and your own labor.

In my opinion, a solar setup has more value for the investment dollar.

[Al and Missy]

Originally Posted by qwertyd10n

Hi all,

I've been pouring over the LiFePo4 related threads since determining that the original flooded batteries in the new-to-us 2019 International Signature 27FB we picked up last weekend are shot. The trailer had been sitting for quite some time and the original owner did not maintain the batteries and I cannot seem to recondition them to a usable state.

We did not expect to replace and upgrade the batteries right away, but we definitely like the tongue weight savings and overall longevity of LiFePo4 over regular flooded or AGM batteries.

That said, I haven't been able to completely wrap my head around exactly what equipment I'll need to upgrade in order to properly take care of the lithium batteries. I believe we'll need the following, but would love for someone to confirm this list:
- LiFePo4 batteries (obviously)
- a new inverter
- a current-based battery monitor system
- an upgraded AC-to-DC charger specific to lithium batteries
- a DC-to-DC charger to allow the lithium batteries to be charged by our TW while towing

I do not have any solar considerations right now and would like to leave the batteries in the battery box.

I realize there are many opinions on which gear is better or worse, so informed, first-hand experience with particular equipment makes and models would be appreciated.

Cheers,
Dion

Why a new inverter? If you are energy limited you don't want to be using an inverter. IF you have to have an inverter you are going to want solar.



Also, I would put the DC-DC converter at the bottom of the list unless you are going to be regularly making long drives.


If I were doing it without solar, and tongue weight wasn't a severe limitation, I would go with two 6 volt golf cart batteries in series. You get better capacity and better life. A Group 24 is 75 Ah and the golf carts are 215-220. At 50% discharge rate, two Group 24s in parallel give you 75 Ah and two GC in series give you 108-110 Ah, a 45% improvement. The batteries are your only necessary cost, but the power monitor might help you manage consumption. When the golf cart batteries age out you can take another look at solar.

[drbrick]

We choose SOK 100Ah 12V LiFePO4 Deep Cycle Lithium Iron Phosphate Battery. We did this for several reasons.

• Cost – The price of ALL lithium batteries in Canada are based on the US Dollar which means you add 35%. (Example: a Battleborn is $1000US = $1350CDN). The SOK is $620US – we purchased two = $1695CDN landed/delivered.
• Design – Built-in Smart Battery Management System. 4000~8000 Cycles Life Span, Maintenance Free. Size 10.2″ 7.9″ 8.1″, 26 lbs. Detachable Cover, Replaceable BMS or Cells. Connect in series for 24V or 36V or 48V Battery Bank, or Connect in Parallel for Larger Capacity (2x100ah=200ah). 7 Years Warranty.

Wire Size was our next consideration. Research tells us that the standard 6 gauge battery wire used by RV manufactures including Airstream falls short of requirement. We would be looking at a 10% power loss. Based on distance traveled and amperage the battery wire specification reach was 2 gauge for this installation ($80).
Charger/Converter Upgrade. We have a IOTA multistage system at present. One of the unique design features with the IOTA system is the ability to upgrade (change out) the Smart Charge Controller unit from Lead Acid to Lithium ($35 upgrade).
Safety Circuit Breaker. Baomain ANL-80A Electrical Protection on the positive battery cable between the positive terminal and the kill switch ($11).
Miscellaneous. There will be the additional need for lugs, straps, screws, additional wiring, 1/2×1 framing etc. ($25+-) This will be determined once we dismantle the Lounge area in Blue Streak and finalize the install plan …. stay tuned ��

If you want to read our journey to install go here married with airstream the-lithium-experiment-introduction/

[OTRA15]

Originally Posted by qwertyd10n

Hi all,

I've been pouring over the LiFePo4 related threads since determining that the original flooded batteries in the new-to-us 2019 International Signature 27FB we picked up last weekend are shot. The trailer had been sitting for quite some time and the original owner did not maintain the batteries and I cannot seem to recondition them to a usable state.
. . .

Welcome to the forum!

Do you have shore power where you are? Why not get some basic replacement flooded-cell batteries in the meantime? This would open some doors which may otherwise may prevent any camping, or perhaps even moving the trailer . . . [thinking . . . running lights, break-away switch, brakes and so forth].

In the overall big picture scheme of things, the minimal cost of new batteries might be cost-effective IMO.

Happy trails,

[uncle_bob]

Hi

A modern self contained lithium from a good manufacturer (BB is one) will have a built in BMS. That BMS will shut off charging below freezing and protect the battery. It also will protect against a number of other issues as well. They are happy "out of doors" as a result.

One 100AH lithium is going to provide about the same capacity as your stock pair of batteries. In real world use it'll be a toss up which one provides more. In a "minimum cost" setup, one is all you "need".

The inverter does not need to be changed out in a minimum cost approach. There also is no need for a DC/DC converter - just disconnect the. charge lead. (Batteries charge poorly from a TV ...). A current based monitor is optional, you *can* run without one. It just makes things a lot easier.

The *only* thing you have to swap out is the converter / charger. The replacement unit could be a $200 item.

A 100AH battery on sale from one of the major's around Christmas can be had for $550 to $700 delivered. I would not get one from a second tier outfit. You want a solid build and a good BMS. Net for the battery plus the converter could be $750.

Again this is all against the "minimum cost" requirement. Anything past these two items is technically in the "nice to have" category. You can go out camping and do all the normal stuff with just these two items.

Bob

[JohnTF]

If you are talking about AGM / GEL etc.
You are not informed enough about batteries in general enough to even talk about lithium batteries .
Every chemistry has there issues , but you need to study them all to know what to do - or what not to do .
It appears you did not research lead acid first - to know how or why to move on .
Point being , it seems to me that most want to be handed to them whatever / instead of doing enough research & understand , that any questions are just an update , as compared to very little knowledge , and going by what you believe vs. understand .
I personally think that understanding is exclusive and never want to even consider believing anything

[dspeltz]

Originally Posted by JohnTF

If you are talking about AGM / GEL etc.
You are not informed enough about batteries in general enough to even talk about lithium batteries .
Every chemistry has there issues , but you need to study them all to know what to do - or what not to do .
It appears you did not research lead acid first - to know how or why to move on .
Point being , it seems to me that most want to be handed to them whatever / instead of doing enough research & understand , that any questions are just an update , as compared to very little knowledge , and going by what you believe vs. understand .
I personally think that understanding is exclusive and never want to even consider believing anything

The problem with Lithium is you cannot charge them below freezing or they will be destroyed, almost immediately. Two 6 volt AGM is way better (even better than 12 volt). Spend another week or so reading everything you can on this. If you never expect to be in freezing weather, they may be fine, but you are looking at $4000 plus (you need a different converter as well, I believe).

[OTRA15]

Originally Posted by dspeltz

. . .
. . . If you never expect to be in freezing weather . . .
, , ,

According to [the OP] Dion's ID under his user name, he lives in Calgary, Alberta, Canada.

[guskmg]

Freezing is not a problem if LIs are installed inside the trailer. If it is warm enough to live in they won't freeze. I have had mine for five seasons and they are working fine.
guskmg

[jimdelane]

You have covered most of your bases.

- LiFePo4 batteries
There are a lot of options. Battle Born are the best known but there are other options.

TRIPPPIN made a point about not charging lithium below OC or freezing. Lithiums should not be charged at below freezing. There are a lot of batteries now available with Low Temperature Cut-off to prevent that. Also, there is options available to address it.

ReLion has a LT series batteries for cold weather
https://relionbattery.com/low-temperature-series-line

Battle Born offer 12V heat pads.

Many companies offer the Low Temp Charge Cut-off as a standard feature of the BMS>

Also, lithium iron phosphate batteries also perform better at colder temperatures than lead acid batteries (SLA). At 0°C (freezing point), for example, a lead-acid battery’s capacity is reduced by up to 50%, while a lithium iron phosphate battery suffers only a 10% loss at the same temperature.

Some options include:

AMPS Lithium
https://lithiummarinebattery.com

Battleborn
https://battlebornbatteries.com

Dakota Lithium
https://dakotalithium.com/

GoPower
https://gpelectric.com/product-category/batteries/

LiFeBlue Battery
http://www.lifebluebattery.com

ReLion
https://relionbattery.com

Renogy
https://www.renogy.com

SmartBattery
https://www.lithiumion-batteries.com

- a new inverter

You do not need a new inverter for lithium batteries. Inverters convert 12V to 120V. If you need to replace your inverter, the only type of inverter to buy is the Pure Sine Wave. They cost more than a Modified Sine Wave but the MSW inverters put out a 'ragged' power which is harder on your electronics, microwave and refrigerator compressor.
Eastwood puts out a good quality 2000/4000 and 3000/6000 inverter.

- a current-based battery monitor system

You do need a battery monitor. The reason is that the lithiums will have a higher constant voltage throughout the discharge. At 50% discharge - the AGM/Flooded Lead Acid will read 12.1V and the lithiums will still be in 12.8-13V. This will lull you into a false sense of security. You will be 80-90% discharged before you start to see any significant drop in voltage and then BAM - you run out.

The Victron 712 is the monitor most desired but costs around $200.

You can pick up a cheap battery monitor on eBay for around $50.
Such as:
Battery Monitor 80V 350A Caravan RV Motorhome UPS lithium iron lead-acid 999 AH
or
Wireless Battery Monitor Meter DC 120V 500A VOLT AMP AH SOC Remaining Capacity
US

Both are adequate but not the Victron.....

- an upgraded AC-to-DC charger specific to lithium batteries


- a DC-to-DC charger to allow the lithium batteries to be charged by our TW while towing

This is to protect your alternator. Renogy puts out a 20A and 40A. Victron puts out a 18A and 30A. There are others out there.

There are 2 things you did not cover.

1. The Converter/Charger: (you may have meant that when you listed the 'inverter')

Progressive Dynamics makes an excellent and affordable charger. Depending on the batteries and battery banks you install, you can choose from anywhere from 30A to 80A charge.

2. Solar charge controller:
You did not mention having solar but if you do.... you want a solar charge controller that will charge lithium batteries. Basically all new charge controllers have added that feature.

You will hear about the Victron brand a lot. They are a very high quality product and lead in bluetooth app products. Renogy is a very good brand and are quite affordable.
Battle Born targeted the RV industry many years ago and can take credit for a lot of the transition to lithium batteries. However, there are many good alternates available. When considering purchasing consider:
1. Battery size - it may be more cost effective to go with a 150, 200, 300 or 400Ah battery.
When putting together a battery bank - connections are points of failure and reducing the number of batteries involved is worth considering.
2. BMS - the battery management system is what protects the battery. The most common BMS is 100A. That limits the charge and discharge to 100A. Unlike AGM/lead acid batteries, each lithium battery charges independantly of all other batteries. The closer the discharge gets to the 100A BMS limit, the more stress there is on the BMS. Some manufacturers offer higher amp BMS depending on the battery.
3. Warranty - you will see warranty vary from a couple of years to limited lifetime. The warranty is an indication of quality. Some manufacturers use recycled cells and cheap BMS. These will be the companies that offer short warranty periods.

A lithium battery should last 10 to 20 years. If you cycled the battery 100 times per year - and it has a cycle life of only 2000 = that is 20 years!!

Best of all, lithiums do not gas, they are light, they can be left partially charge indefinitely, they never are equalizes, they have higher voltage, deep discharges do not damage them, they are truely maintenance free and last a very, very long time.

[Sport 16 STL]

This is the low cost pathway. For about $300 you can put two panels on the roof. I would do a couple of panels before some of the items on your list.

[OTRA15]

Originally Posted by qwertyd10n

. . .
We did not expect to replace and upgrade the batteries right away, but we definitely like the tongue weight savings and overall longevity of LiFePo4 over regular flooded or AGM batteries.
. . .

Will the trailer be located in Calgary, Alberta, Canada for winter, and what will the interior temperature be? If unheated, and no heated storage, does this not rule out lithium batteries? [unless you remove them for the winter and store them in a heated space?]

Thanks,

[SeaJim]

Reading the thread, you've got quite a bit of info so far, most of it useful. For background, though I don't have the RV electrical system chops of several posters here, I recently switched our 23 FB to LiFePo4 batteries in the battery box and I've been through Calgary winters.


So, first point is, Calgary winters are frigging cold. Here in Seattle having batteries in the box is fine, since we aren't doing trips where temps are below 0degC/32degF for 24 hours a day. Since you may have -30degC for long periods, you have probably looked into how different battery chemistries are affected by these temps. In any case, how you plan to use your rig in winter there will figure more in your plans than we southerners consider.


Second, if you're planning to get your rig on the road before the snow flies, I'd go with just replacing your existing batteries or maybe going to 6 volt if they fit your battery box and then add a battery monitor so you can measure your power draws and proceed from there.


Having said that, Uncle Bob has outlined a good plan for migrating to LiFePo batteries with minimal hassle / changes. Be aware that you need to check battery dimensions to be sure it will fit in your box. Also, the Victron 712 is a good tool for monitoring power use, with its iphone app, but it does need to be connected so all loads connected to the negative battery terminal go through it, and there is a sensor that connects to the positive terminal. To avoid running wires from the box to the coach, you need to install the BMV712 on the battery box, which is the route I took, based on info in this thread

https://www.airforums.com/forums/f44...as-205312.html.


Good luck sorting all this out, enjoy your new rig!

[Suza]

Regarding Lithium and cold temperature conditions:

We have ordered a trailer (not an AS) equipped with a Lithium/solar package:

- (2) 200 AH LiFeBlue Lithium HCLT Batteries (400 AH total)
- 340 Watt Solar Package with Charge Controller
- 3000 Watt Inverter
- Micro-Air soft start capacitor for the A/C

The LiFeBlue Lithium Batteries allows you to use 85% capacity. Every LiFeBlue Battery has Wireless Bluetooth communications built in. Their free IOS or Android App called Smart Connect keeps you informed about the functioning of your battery. Also included in their App is a Battery Monitoring feature so you will always know the State of Charge (SoC) or how much energy is left in the battery. The built in BMS system offers 8 different protection modes including, over and under voltage, over and under temperature, over current, short circuit and more. The built-in heating system allows you to use your batteries down to -4 degrees Fahrenheit.

Probably more power than we need, but less worry about SOC while boondocking.

Also know that Lithium batteries do not have to be vented, so they can be placed inside, if temperature is a concern and the batteries are not heated.

Another consideration that I haven't seen mentioned is that battery type is a factor in resale value (if that is something you care about). With Lithium soon to be the standard for RV power, you might take that into consideration.

I would suggest nothing less than two 12v or four 6v AGMs - not certain how many the AS battery box can hold.

[wcrockett]

Originally Posted by uncle_bob

Hi

A modern self contained lithium from a good manufacturer (BB is one) will have a built in BMS. That BMS will shut off charging below freezing and protect the battery. It also will protect against a number of other issues as well. They are happy "out of doors" as a result.

One 100AH lithium is going to provide about the same capacity as your stock pair of batteries. In real world use it'll be a toss up which one provides more. In a "minimum cost" setup, one is all you "need".

The inverter does not need to be changed out in a minimum cost approach. There also is no need for a DC/DC converter - just disconnect the. charge lead. (Batteries charge poorly from a TV ...). A current based monitor is optional, you *can* run without one. It just makes things a lot easier.

The *only* thing you have to swap out is the converter / charger. The replacement unit could be a $200 item.

A 100AH battery on sale from one of the major's around Christmas can be had for $550 to $700 delivered. I would not get one from a second tier outfit. You want a solid build and a good BMS. Net for the battery plus the converter could be $750.

Again this is all against the "minimum cost" requirement. Anything past these two items is technically in the "nice to have" category. You can go out camping and do all the normal stuff with just these two items.

Bob

I agree with you Bob. A minimum requirement is the lithium batteries and a converter or battery charger that will charge them. The existing converter will take them up to about 13.6v and you need to get them about 14.4v. You can do that by putting in an new inverter that can be set to charge Lithiums or you can buy a regular 110v battery charger that has settings for lithium’s. You can also
Charge the lithiums with your existing convert and they will charge but not up to 100%.

[SilverWind]

Give AM Solar a call. They are pioneers in RV solar and have been installing lithium systems for a while. They sell an array of hardware solutions to make lithium work. I'm sure you can get expert advice from them, even for non-solar installations. They've installed complete solar systems on two of my Airstreams. https://amsolar.com