Thoughts on FWC factory upgrade of electrical system to 135 AH Dakota Li battery and Redarc 25 A DC-DC charger

[bikeandski]

I've read and searched thru many FWC Li battery upgrades threads, but have not found any feedback on the factory upgrade option presented in their Oct 2023 video. I presume many of the knowledgeable members are aware of this. Some info and my thoughts below, I would appreciate other comments.

My camper is a 2017 Fleet.

The system is composed of from one to three 135 AH LiFePO4 heated batteries from Dakota, Redarc 25 A DC-DC charge controller, Victron BMV-712 monitor, Victron Bluesmart 12V/30A shore charger, and an upgrade to fused 8 AWG wiring. Cost is $2,995 with one battery, and 3,995 and 4,995 for two and three batteries respectively.

Retail cost of the system component list with one battery is approximately $2k, so labor is roughly $1k. I have experience with electronics and am fully capable of doing this myself, although I tend to be slowed by OCD and overthinking. I live not far from the factory, and this is a tempting approach get this implemented with no effort and have a factory supported system.

My thoughts and reservations are:
- I should be comfortable with a 100 AH of storage, and the 135 AH Dakota battery adds a little margin without stepping up to two 100 AH batteries. Dakota advertises a quality battery, 11 year warranty, 5,000 cycles, bluetooth connectivity, and a premium price roughly 30% more than an 100 AH heated Battleborn (with 35% more capacity, so comparable pricing). My brief look into the info reviews from this manufacturer is not especially reassuring, except on their website. I might expect some level of warranty/support from FWC, this is something I will look into.
- For a full system upgrade, I'd prefer to see 40 A of DC-DC charging to replenish the system more swiftly from the alternator when needed.
- Wire upgrade to 8 AWG seems a little light while going to the trouble. Barely enough for the 25 A of charging, maybe they utilize the same plug that limits the wire size and charge current.
- The Redarc DC-DC converter and Victron battery monitor seems to be best in class. The 30 A Victron shore charger has a cooling fan that can be turned off for slower charging in "night mode". A lower current passively cooled AC charger would be fine for me.

Any thoughts on the system, my considerations, or other input would be appreciated.

Link to FWC video describing the upgrade:

Now Offering LITHIUM UPGRADES for Four Wheel Campers

Exciting News for Four Wheel Camper Owners! Upgrade Your Off-Grid Power System ⚡ In this video, we are thrilled to introduce an amazing opportunity for you to take your off-grid adventures to a whole new level. Whether you own a camper purchased before May 2023 or one of our newer models, we’ve...

fourwheelcampers.com

 

[Vic Harder]

Good analysis of what you get for your money. $1000 labor is not unreasonable. Wiring can be very time consuming and expensive if you have to re-do things.

Given a choice between BB and Dakota, I'd lean towards BB, but I am biased, given that I have two of the BB (unheated).

I agree that 40A DCDC would be better, especially if you have more than 100AH of battery. Less driving time to get fully recharged is better, and LiFePo4 batteries don't mind fast recharging (up to 0.5C or 50AH on a 100AH battery).

I agree on the wiring too. Given the effort (labor) required to upgrade the wiring, I'd get bigger wires I can afford, up to 0AWG. Why so fat? That way you could easily use the camper batteries to "jump" the truck if needed. I used 2 AWG in my build, up to the 100A breaker in my camper battery box. 4 AWG from there for some wires, 2 AWG between the batteries and to the 3000A pure sine wave inverter.

My Victron AC/DC charger fan rarely (if ever?) kicks on. The DCDC does not have a fan, and should. I added a high CFM (75cfm?) computer fan that keeps it cool. Noisy as heck, but in only runs when I am driving, so I rarely hear it.

Don't forget quality buss bars and fuses, plus a labeling tool to help later when you are wondering "where the h#ck does that wire go?"

 

[kmcintyre]

It sounds like you are comfortable with doing it yourself and if you have the time, I'd go for it. Another thing to consider is building your own battery pack (lifepo4). It's really pretty easy and could save you a lot of money. I built mine about 4 years ago and it was about $460 with my Victron (18amp) DC-to-DC charger being the most expensive part of the job ($164). So far, everythingr has gone well. I also replaced all the wiring with 6awg and added thermal fuses, etc.

 

[bikeandski]

Thanks both for your feedback and insights. A business with expertise in this area proposed a 50 Amp Victron DC-DC charger, and to not replace the Iota shore charger or Zamp solar charger. I like the sound of this approach. Fewer components to purchase, less labor to swap items out, 2X the alternator charge current, best in class Li battery, and robust wiring to the truck. I don't expect to use shore power often, so the Iota will do fine when needed, and the Zamp and DC-DC charger will provide a full and healthy charge profile to the BB battery. With this approach the DIY savings is about $1,500, the effort less, and my system will have a BB battery and 2 AWG wiring to the truck which I feel are better features.

I plan to start procuring parts this weekend during black friday sales. Then look deeper into the implementation of this, photos, wiring diagrams, etc.

The first question to address is if the Battleborn Smart battery system and bluetooth monitoring is useful to me, for $95 more. My first look into it suggests the system shows 8 or 10 status indicators available for the battery (over/under voltage/current, SOC, etc), and FW updates. I think the BMV 712 will provide a better system status, and suitable SOC level. Seems this is geared for multiple battery setups. Any thoughts appreciated.

 

[Jon R]

One thing I found helpful to get a neat, efficient use of the space in a tight DIY installation was to mock up the layout of the battery compartment with plywood scraps to lay out the locations of devices, bus bars, and wire routing. Once I had it the way I wanted it I transferred the screw hole locations to the compartment walls and pre-drilled for the mounting screws, and it all went in neatly and quickly. It also allowed me to pre-make all my heavy cables.

 

[bikeandski]

Thanks Jon. Great tip, and awesome photos. This really inspires me to see what the finished system should look like and how to get there. The factory wiring is so distributed, with the Blue Sea ACR in the front underseat cabinet near the AC and DC fuse boxes, I had not yet considered where the DC-DC charger, shunt, primary fuses and all should be located. Seeing it all laid out so cleanly in the battery box just opened my eyes to the solution.

If you happen to have any type of materials list and/or interconnect diagram, that would really make my day.

Thanks again, and Happy Thanksgiving to all.

 

[Jon R]

I will put together a list and diagram, but not today obviously. I’m happy to help.

 

[bikeandski]

I was hoping you might have some sketches or notes you could snap a picture and share. I do not expect you to create any documentation for my benefit. I'll be digging into over the next week or two, any info would greatly appreciated. I read thru several of Vic's post some time ago, I expect he may have shared a diagram or parts list at one time.

I'm going to order up a BB heated battery, BMV-712 monitor, and Orion XS-12/12-50 Amp DC-DC this weekend during black fri sale. I'll follow up with wiring, lugs, breakers, buss bars, etc in a few weeks as I figure out the topology.

Looks the latest Orion XS 12/12-50 Amp DC-DC charger is a compact, efficient, and cool package. I'm going to try and prototype a layout that would leave room for a second battery in the Fleet battery box, maybe leave an extra post on the bass bars as well.

 

[rando]

If you are considering a lithium battery with bluetooth (which you should), then you may not need the BMV-712. The battery will provide you all the info and BMV-712 does and more. The only reason to add the BMV is for the physical display if that is important to you. Renogy has a lithium battery that has a remote mountable physical display, that could be a good option as well.

 

[Vic Harder]

If you want to save a few $$$, and don't need a "display" the "Smart Shunt" that Victron sells is also very good.

@rando, I'm not sure I understand your information about the BB battery's BMS providing all the info you need. I may have missed it, but my BB batteries don't have a bluetooth accessible BMS (that I know of?)

 

[rando]

I am not speaking specifically about the BB batteries, but many of the current lithium batteries provide access to the built in BMS via bluetooth and an app or display. The BMS is keeping track of all the relevant info about the battery, voltage, state of charge, capacity, individual cell voltages, number of cycles etc. If you can get this directly from the battery, then you don't need a BMV unless you want the physical display. Given the choice, I would lean towards a battery with an app - I almost always look at the battery app over the BMV or Victron App. If you ever do have a battery shutdown or fault, then then app is critical as it actually tells you what is going on.

For example, here is what the Renogy app shows (stolen from google):

And here is what my DIY BMS shows:

 

[bikeandski]

Thanks Rando. I am reconsidering a monitor in light of Black Friday purchases... The sale on Litime batteries was too good to pass up, $227 each for two 100 AH heated batteries, with bluetooth, in a group 24 pkg that fit side by side in my fleet battery box. Not a top brand, but Will Prowse had a couple recent reviews and was very impressed with this BMS, the bluetooth OK as well.

I am considering occasional use of a high output inverter to charge an ebike battery. I rarely run the ebike battery below 30%, but the 750 WH capacity is more than half of a 100 AH house battery, so the two batteries and 50 Amp charger should support this when needed.

My question to the group:
I'm considering an Anderson connector in the battery box wired to the buss bars with the two batteries in parallel series. This for occasionally plugging in a 2000W inverter for ebike or other use, and possibly plugging in an AC charger with a lithium profile to top off the batteries from shore power in lieu of the Iota charger with AGM profile. This accessory power plug for inverter/charge circuit would include the main battery breaker for protection and the shunt for monitoring usage. I'd rather not permanently install the inverter, and this seems like a nice option. AM I OVERLOOKING SOMETHING CRITICAL WITH AN ACCESSORY ANDERSON POWER PLUG IN THE BATTERY BOX?

Having two batteries with bluetooth, I can go without the monitor as suggested. However, the monitor would provide a quick glance of the battery bank status and system use, without having to query each battery on my phone, useful when running a high load inverter. I expect to adjust the Orion XS 50 Amp charger settings, so it might be convenient to have the BMV charge status on the same Victron phone App as the charger.

Another interesting topic is the Litime battery heating approach. Rather than activate heating to keep the battery from going below temps suitable for charging, the Litime approach allows the battery to fall below the low temp charging limit (32F), while still allowing discharge down to -4F before total cutoff. Heating the battery back to 41F to allow charging can be done with current from the charger or internal power discharge thru bluetooth command. This sounds appealing to keep discharging below the charge limit, with methods to heat back up as needed. I could see my usage going below freezing, but rarely sub-zero. From 32F down to -4F when charging is disabled, and discharge is allowed, it would be natural to run the heater and warm things up.

I'm curious to see how these batteries and the features perform. Looks like they're on sale for a few more days if anyone else wants to check it out.

Thanks again for the insights.

 

[bikeandski]

I can see bluetooth on the battery is a game changer to see real time battery state, history, activate heating, and other details. Thanks for sharing.

I'm leaning toward the BMV-172 for convenience with the money I saved on the batteries . I may hold off a bit on the purchase while I work on the wiring and component layout.

PS: Battleborn recently released a few smart batteries with bluetooth.

 

[rando]

Thanks Rando. I am reconsidering a monitor in light of Black Friday purchases... The sale on Litime batteries was too good to pass up, $227 each for two 100 AH heated batteries, with bluetooth, in a group 24 pkg that fit side by side in my fleet battery box. Not a top brand, but Will Prowse had a couple recent reviews and was very impressed with this BMS, the bluetooth OK as well.

I am considering occasional use of a high output inverter to charge an ebike battery. I rarely run the ebike battery below 30%, but the 750 WH capacity is more than half of a 100 AH house battery, so the two batteries and 50 Amp charger should support this when needed.

My question to the group:
I'm considering an Anderson connector in the battery box wired to the buss bars with the two batteries in series. This for occasionally plugging in a 2000W inverter for ebike or other use, and possibly plugging in an AC charger with a lithium profile to top off the batteries from shore power in lieu of the Iota charger with AGM profile. This accessory power plug for inverter/charge circuit would include the main battery breaker for protection and the shunt for monitoring usage. I'd rather not permanently install the inverter, and this seems like a nice option. AM I OVERLOOKING SOMETHING CRITICAL WITH AN ACCESSORY ANDERSON POWER PLUG IN THE BATTERY BOX?

Having two batteries with bluetooth, I can go without the monitor as suggested. However, the monitor would provide a quick glance of the battery bank status and system use, without having to query each battery on my phone, useful when running a high load inverter. I expect to adjust the Orion XS 50 Amp charger settings, so it might be convenient to have the BMV charge status on the same Victron phone App as the charger.

Another interesting topic is the Litime battery heating approach. Rather than activate heating to keep the battery from going below temps suitable for charging, the Litime approach allows the battery to fall below the low temp charging limit (32F), while still allowing discharge down to -4F before total cutoff. Heating the battery back to 41F to allow charging can be done with current from the charger or internal power discharge thru bluetooth command. This sounds appealing to keep discharging below the charge limit, with methods to heat back up as needed. I could see my usage going below freezing, but rarely sub-zero. From 32F down to -4F when charging is disabled, and discharge is allowed, it would be natural to run the heater and warm things up.

I'm curious to see how these batteries and the features perform. Looks like they're on sale for a few more days if anyone else wants to check it out.

Thanks again for the insights.

You can't have the same pack wired for series and parallel at the same time - you would short them out (draw this out). You would need to disconnect them and rewire for series, but that would kill your 12V supply for lights etc. I would probably just use a 12V inverter.

I have not been around this forum much of late, but I remember someone had issues with LiTime batteries in parallel - it would be worth searching for. They do sound like a killer deal, but maybe you should just by a 200Ah battery to avoid any issues?

I have been using my lithium battery pack for about 7 years now, and have a pretty good feel for how it performs, as a result I rarely look at the state of charge, as I know I almost always have plenty of juice.

 

[bikeandski]

Brain fart, the two 12V batteries will be in parallel.

Spec sheet says good for 4S4P. Too late to back out, I already rolled the dice.

 

[Jon R]

There was a long thread recently from a forum user who bought two Litime batteries and attempted to use them in parallel. Their BMSs did not play together to charge and discharge the two batteries together. After trying to get it figured out with the company in several interactions he finally gave up and returned the batteries.

2 LiTime 100ah Bluetooth LiFePO4 in parallel

I have 2 LiTime 100ah bluetooth LiFePO4 batteries wired in parallel and it appears by looking at the BMS of both batteries that only one battery is under load. I attached photos of both BMS. If anyone has these batteries wired in parallel do you have the same issue when looking at both BMS...

www.wanderthewest.com

 

[bikeandski]

Thx for link. I chased down a few reviews, I should have searched on WTW before pulling the trigger.

Just a few months ago, and the thread is four pages. I better shake them out when I get them, hopefully get a return if they're not going to work together.

I do believe you get what you pay for, pity I did not follow my own advice. A bit of irony that last week I was doubtful about Dakota Lithium from FWC and wanted to go with BB.

 

[BFH4N]

I did this exact same upgrade to my 2014 Fleet last year and I am very satisfied with it. Everything works well.
Truck - to - camper wire is #4, which is overkill but it was already in place.
I can send you my wiring diagram, if you want.

 

[Jon R]

I did this exact same upgrade to my 2014 Fleet last year and I am very satisfied with it. Everything works well.
Truck - to - camper wire is #4, which is overkill but it was already in place.
I can send you my wiring diagram, if you want.

Did you use two LiTime batteries?

 

[Vic Harder]

And why do you think #4 awg is overkill? I ran mine with #2 welding cable, and have seen 90A over that wire over extended periods of time. If I ever go bigger on my house battery bank (200AH BB now) I'll be glad I have enough wire in there already. I have used the house batteries to jumpstart the truck... instantaneous current flow was likely over 100A for that.