Converter voltage drop

[mpvuk]

Just replaced lead acid with LFE (200ah) and want to change converter to a lithium specific unit. Current unit WFCO WF-9855. My LFE's suggest a 14.4v bulk charge. Converter's I'm considering all bulk at 14.6v.

Do I take voltage drop into account when determining bulk charge at the battery? And will a 14.6v at converter work in my situation?

I have 6g on an approx. 10' one way run between battery and converter. New converter will be a 45A model. A 1.5% drop will bring 14.6v down to 14.4v. Based on my limited knowledge, I'm thinking I'll have at least a 1.5% drop.

Also note that I'm planning on getting a 45A unit to replace the WFCO 35A. Am I correct that current wiring will handle that?

Thanks in advance for your input.

[time2roll]

MW-NPB-750 is a good product. I have the 450.

[mpvuk]

OP here...thanks all for the input. A took a closer look and my converter to battery run is closer to 15' one way, with mfg installed 6g wire. So a re-wire seems appropriate. So I've decided to keep the WFCO and use as a converter only when on-grid. It works fine in that capacity.

Then buying a Mean Well NPB-750 charger to use with the generator off-grid. I can place about 3' from Batteries (which are 2 Weize 100ah). I think a better solution than replacing the converter/charger with a better one (was leaning toward the PD 9200 series). And I would still want to upgrade wiring if going the replacement route. I have left over 2/0 wire from the battery install that I can use with the Mean Well.

Still open to suggestions if I'm still wandering around left field on this.

[3_tons]

BFL says:

“Hope the OP is still here and hoisting all this good stuff in!”

Me too, I just had a double shot of Moroccan espresso 🙂 - lol !!

[BFL13]

Itinerant1 wrote:
My personal choice is a programmable inverter/ charger but my use is much different than most.

If I was downsizing and was going to stay with a converter than it would be one that Time2roll suggested in the 3rd post of this thread. I do have one of those converters hanging in the front compartment just disconnected from the system.

Thanks. Totally agree/concur (not sure which one of us is senior) on that.

Hope the OP is still here and hoisting all this good stuff in! 🙂

[Itinerant1]

My personal choice is a programmable inverter/ charger but my use is much different than most.

If I was downsizing and was going to stay with a converter than it would be one that Time2roll suggested in the 3rd post of this thread. I do have one of those converters hanging in the front compartment just disconnected from the system.

[3_tons]

Itinerant1 wrote:

pianotuna wrote:
Hi Gdetrailer,

I agree. Li are FUSSY.

They can work well.

I'll never own them as I camp in extreme cold.

They're not that fussy, my last hookup to a power pole was Nov 3rd last year for a night when there wasn't a boondock spot. Just solar and an occasional hold over from the generator during spring. Can't be that fussy. 😉

There seems to be one or two committed outliers here (non-LFP users…) that like to pretend that LFP’s are fussy - lol… Though comfortably frozen in their rigid dogma (soooo disinterested in LFP’s, kinda makes me wonder why they bother to post??:?)…Yet lots of ‘solid and non-theoretical’ information has been provided here by some ‘real-world’ actual users, and from my perspective this is where one need focus…

A review of advice provided here (and past efforts penned elsewhere…) will reveal that there’s no supposed ‘Black Art’ to charging or maintaining a LFP, in fact, beyond the ‘hocus-pocus’ machinations that these few ‘non-users’ suffer to promote (validating their format of choice I suppose?? - using discernment you can avoid these ‘seemingly plausible’ distractions…). Truth is, LFP’s are quite forgiving, and in fact *LFP has by far has been the most task-free, and least bothersome format that I’ve used…

* (just avoid charging below 32dF, or provide an alternative provision)

3 tons

[BFL13]

Itinerant1, what would you advise the OP wrt to his possible converter replacement for his ? brand LFPs?

[Itinerant1]

pianotuna wrote:
Hi Gdetrailer,

I agree. Li are FUSSY.

They can work well.

I'll never own them as I camp in extreme cold.

They're not that fussy, my last hookup to a power pole was Nov 3rd last year for a night when there wasn't a boondock spot. Just solar and an occasional hold over from the generator during spring. Can't be that fussy. 😉

I should add that the longest stretch boondocking off of solar and hold over charge with generator and lfp was over 1,000 days. Not that fussy.

[BFL13]

mpvuk wrote:

theoldwizard1 wrote:
Any QUALITY converter/charger will have a specific setting for LiFePO4. Use it !

Personally, I would just eliminate the converter and buy an inverter/charger/automatic transfer switch.

New to this so hopefully replying in proper format...all LFE specific converter/chargers I've found have a 14.6V bulk phase. My battery mfg says to stay at 14.4 or less in bulk. Are there LFE chargers that start at 14.4? Regarding an inverter/charger, I already have a 2200W pure sine wave inverter that Works great. My best value seems to be using existing inverter and upgrading the converter.

PowerMax says they made their LFP compatible converter (LKL model) according to what BattleBorn told them and that's that. Obviously, PD did the same. That leaves out other LFP makers and their specs, which are not always the same as BB's.

At least the LKL still has the adjustable voltage option, so you can't go wrong there, unlike PD's L model unless your batt's specs are the same. As posted earlier, with your specs you will be ok with a standard 14.4v 3-stage PD with the Charge Wizard, if you find that easier than using the manually adjusted PMX LKL or LK.

Perhaps your batts can stand 14.6 and just have recommended 14.4 like some other LFP specs say? Can you link to your particular brand and model of LFP so we can see its specs?

[pianotuna]

Hi Gdetrailer,

I agree. Li are FUSSY.

They can work well.

I'll never own them as I camp in extreme cold.

[time2roll]

Gdetrailer wrote:
I thought the idea of LFP batteries was to eliminate "maintenance" and hassle :h

Looks like you signed on to a lot of work and hassle :S

MY FLA requires a simple plug in and forget and once a year check and add water if needed :B Maximizing my enjoyment of my RV without the work.

My PD takes very good care of my FLAs yr round and keeps them in good working condition that takes them well over 10yrs of life.

And the PD charging the LFP will not need that water, provide twice the power, and live through three sets of FLA.

[3_tons]

Gdetrailer says:

“Looks like you signed on to a lot of work and hassle….”

Maybe so to the uninitiated (or mischievous?? - I donno…), but winning over FLA converts was not my goal, nor a cogent point of the OP’s thread…Perhaps you should consider sticking with wet-cells and just feel self-assured (vindicated…) about what’s working well for you - Glad to hear it!!

3 tons

[Gdetrailer]

3 tons wrote:
FWIW, LFP Simple Rules I live by - JMO

1) Except for occasional cell re-balancing, no need to fully recharge a LFP on a ‘wet-cell like’ routine basis…

2) Monitor closely the last few percent of recharge to 100% SOC thru to end of cell-balancing activity…

3) Post cell-balancing activity, discontinue Boost charging (avoiding the longer term) - shut-off 12v converter (at breaker) and thereafter run minor 12v loads from the battery (this still supplies active 120v for larger appliances). When off-grid, LFP can be supplemented with harvest…

4) For long term storage, disconnect and store LFP somewhere in the mid-SOC range (60-40’ish % SOC range).

3 tons

I thought the idea of LFP batteries was to eliminate "maintenance" and hassle :h

Looks like you signed on to a lot of work and hassle :S

MY FLA requires a simple plug in and forget and once a year check and add water if needed :B Maximizing my enjoyment of my RV without the work.

My PD takes very good care of my FLAs yr round and keeps them in good working condition that takes them well over 10yrs of life.

[3_tons]

BFL said:

“I still have not got an answer for what you do if your rig has an inverter/charger. Last heard, an inverter/ charger will not operate at 12v unless it it is connected to a battery to run its own systems. Not sure if it still would do 120v pass through.”

************

My pass-thru inverter-charger always stays connected to the batteries, whether on shore power or not…As power passes thru, it normally remains in just the ‘standby mode’ (or, OFF) - it’s built-in ATS switch prevents conflicts with incoming shore power…

3 tons