Specific Lithium Batt Question

BrianG

Senior Member
Joined
Jan 25, 2015
Messages
196
Location
Northern Nevada
Hi all,

Just got back from camping for couple of days and with little sun my batteries didn’t last three days with the frig running.

My 2015 Hawk has two original AGM 75 ah batteries from the factory. I have the Zamp 30 amp charger.

This controller has a lithium battery mode. Has anyone replaced their AGM batts with lithium’s and just switched the controller to lithium. For instance just replacing mine with two 75ah lithium’s.

Trying to keep this as simple as possible!

Thanks all
 
This will work, it’s just a question of how efficiently. The charge parameters for LiFePO4 batteries vary from battery to battery. The Zamp parameters are found on page 8 of the Zamp manual. Personally I switched the controller to a Victron which is programmable and provides a of reporting via an app. Same is true with the Iota shore power charger, not ideal but will charge, just slowly and not to 100%. You will want a DC-DC charger, like the Victron Orion-Tr Smart, for alternator charging and a heavier wire run from the truck battery. This is really true of most newer vehicles. https://amsolar.com/solar-panels-for-rv/2020/1/10/how-to-determine-if-you-have-a-smart-alternator-system

In the end it’s all worth it.

Dean
 
It will work just fine. Lithium really isn't that picky about charge parameters.
 
I just replaced my two 75ah batteries with two batteryborn 100ah lithium batteries, they did fit into the original battery boxes which are group 24 after I hacksawed off one side. Which allows you to use the same box and strap to secure your new larger batteries, They easily fit into the OEM space with this modification. As far as your zamp charger if it has a lithium setting, you will be fine. I had to change out my morningside Charger because it didn’t work with a lithium charging profile and if you have the IOTA converter they sell a module that plugs into the system and changes the converter to a lithium charging profile, basically a two stage charger.
In short your current system should work with lithium batteries with modest modifications.
 
The Iota with the built in IQ4, which FWC uses, is not compatible with with LiFePO4 module. I learned this the hard way by buying it without reading the fine print.

Dean
 
That said the 2011 Eagle Iota allows a very easy plug in dongle that changes the LiFePo4 battery....mine works great.
 
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Fyi my 2013 Hawk IOTA converter did not have the built in IQ4 so I was able to add the IOTA lithium profile charger from IOTA, not sure which year FWC went to the internal IQ4 IOTA but many FWC owners will easily be able to change their IOTA converter to a lithium friendly charger. My plug in cost $20 and I checked the charging profile and it matched what my Batteryborn batteries wanted. I was able to reuse the existing battery boxes by removing one end with a hacksaw which allowed me to fit the slightly longer Batteryborns 100ah right in. I did replace the Morningside charge controller with a Victron controller and added the Victron monitor as well. Batteryborn has video on exactly how to setup Victron charge controllers for their batteries which made it very easy. I also upgraded the battery wires to 4awg from Amazon which I use to connect the batteries in parallel since the stock FWC wires looked a little small to me.
All this took me less than an hour.
 
I suspect that a lot of us are looking at the same question as our AGM batteries get to the end of their life cycle.

AGM vs Lithium: Because the (2) 75 Ah AGM batteries (standard in FWC dual battery set ups) can only be drained to about 50%, a single 100 AH LiFePO4 battery, which can be drained 90 plus percent, can provide a similar number of Amp hours. The initial cost of Li is higher, but the lifespan (because it can go through more charge cycles) promises to make the initial cost a break even by lasting longer.

Protect Your Alternator: What I did not understand was that a Li battery will draw more to charge than your AGMs. This is because Li batteries charge faster. Most truck alternators are not built to handle that extra work. Now, if you have a 3500 with a big ole alternator, you may be okay. Otherwise, you need to protect your alternator from overworking -> overheating -> letting you down : (

The DC to DC charger is made to protect your alternator by throttling down that charge. By limiting the amperage on the charge side, it protects your alternator from overworking and getting you in trouble.

Now, full disclosure: I'm learning about all of this as I prepare to change over and let my 5 year old AGM go. All of you much smarter folks should feel free to correct / redirect / teach me / us : )

My plan is to use a DC to DC Charger (Victron Orion DC to DC 12 / 12 / 18 Amp) and a Battle Borne 100 Ah LiFePO4 battery. https://cemarine.com/products/victron-orion-tr-smart-12-12-18-18a-220w-isolated-dc-dc-charger-or-power-supply-ori121222120

Any hints, suggestions, etc would be welcome!

Thanks all,

Karl
 
Lots of great information, thanks. My problem is this, I’m great at installing ceiling fans,, but re-wiring my 2015 Frt dinette Hawk with the tight battery compartment seems out of my ability level. Wish I could get it done by a qualified individual!
 
BrianG said:
Lots of great information, thanks. My problem is this, I’m great at installing ceiling fans,, but re-wiring my 2015 Frt dinette Hawk with the tight battery compartment seems out of my ability level. Wish I could get it done by a qualified individual!
It looks like you are in northern Nevada? If so, contact KP Pawley in Reno. He has installed many lithium battery systems in FWCs

https://www.sixguntwelvevolt.com/
 
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Honestly I think it is way more complicated to wire a ceiling fan than switch out my 2 OEM FWC batteries with the Batteryborns or any battery and they have a bunch of videos that are specific to common charge controllers that tell you exactly how to program them. I simply punched in the numbers they recommended. There isn't a lot of rewiring, just use the existing wires. And I managed to fumble my way through installing a Victron battery monitor (712) which I really like AND I simply followed the batteryborn video from their website on how to program the proper numbers for a lithium battery. If I did it, really anyone can....
 

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