Converter changeout for lithium batteries

[Thomaisheenjames]

Hi.Plan on upgrading to lithium.My converter/charger is the standard wfco 55a.Was thinking of replacing with the wfco 55a autodetect as it should be an easy drop in.Think factory wire is 8ga .Would be very happy if i could get a 40/50 amp charge rate.Would appreciate any thoughts.Regards....Tommy.

[Aussieguy]

Unless you are installing a real big battery bank
you probably don't need to increase your amps ... the existing charger will do OK at replacing your amp use.

Spend the money on some GOOD solar and solar charger... solar will charge lithium very well. 200w or more about same price as changing out the converter
BUT more useful if you go off grid


OR

you can add a cheaper lithium charger and plug that into the battery once in a while to do a top balance
GOOD solar will allow the lithium battery to get top balanced.

Check with your battery supplier / manufacture on their recommendations BEFORE spending a lot of money.

------------------------------------------------------------
If you do replace the converter ... don't guess on the wire size.
measure the wires diameter and approx length make sure they will allow the additional amperage ...

[TitanMike]

Originally Posted by Thomaisheenjames

Hi.Plan on upgrading to lithium.My converter/charger is the standard wfco 55a.Was thinking of replacing with the wfco 55a autodetect as it should be an easy drop in.Think factory wire is 8ga .Would be very happy if i could get a 40/50 amp charge rate.Would appreciate any thoughts.Regards....Tommy.

Based on several recent posts telling of how the WFCO auto-detect converters don't "detect" I'd definitely pass on any "Auto". They may be desirable for manufacturers who want to be able to toss in any battery the Dealer or Customer chooses at time of sale but they are apparently quite unreliable.

That said a manual switch (LiFePo4 or Lead/Acid) may be just fine. They don't rely on voltage readings at the innards of the converter to pick which battery they're going to charge but rather are "told" at setup and don't have amnesia at every startup.

Better yet, consider replacing the actual converter section in the Power Center or if the Converter is a stand alone unit (Deck Mount) replace either with a Progressive Dynamic's Converter suitable for "Lithium" batteries. A much more reliable product as many here have found.

[Thomaisheenjames]

Dear Aussieguy.Thank you for the great advice.I plan on putting 500w solar on the roof,and camp mostly off grid.I already have a good quality portable charger that will do lithium.Have read that its ok to plug in a second charger on top of the onboard charger,but am a little suspicious of this.Anyways you just save me a couple of hundred bucks,am not going to touch the onboard charger.Regards....Tommy

[Thomaisheenjames]

Dear TitanMike.Thank you for your advice.Based on great information that i got from Aussieguy i am not going to change the converter/charger at this time.If i do have a reason to do so in the future i will certainly heed your great advice.Regards....Tommy.

[blangan]

I converted last year. I replaced the MBA portion of my converter with this.

https://parts.unitedrv.com/products/...wf-8955lis-mba

15 min job. I have 190w of solar, going to double that this year. I changed my controller to a victron 100/30. Probably should have gone with a larger one so I could continue to wire panels in parallel but if I go over 400w, I will just change to series. I prefer to be able to fully charge the batteries when plugged in as sometimes you may be stuck with cloudy days when off grid.

I also added a breaker for the panels wired in before the controller while I was at it and moved the batteries inside.

[Thomaisheenjames]

Thank you Blangan

[TacomaJoe]

I swapped out my WFCO with a PD9160L back in September. I had stuck it into the original location but now am re-thinking that and will be moving it over near the batteries. Doing that will reduce voltage drop of the charging circuit.

[RonChristine]

I have a solar suitcase from Renogy 200 W. I use it to charge my AGM batteries and it works great. Plan on getting 2 Lithium batteries which will be great with the solar Panels. I checked with WFCO or Renogy cant remember which and the said there converters work fine with Lithium
Ron

[PhilFromMaine]

Originally Posted by Aussieguy

Unless you are installing a real big battery bank
you probably don't need to increase your amps ... the existing charger will do OK at replacing your amp use.

Spend the money on some GOOD solar and solar charger... solar will charge lithium very well. 200w or more about same price as changing out the converter
BUT more useful if you go off grid


OR

you can add a cheaper lithium charger and plug that into the battery once in a while to do a top balance
GOOD solar will allow the lithium battery to get top balanced.

Check with your battery supplier / manufacture on their recommendations BEFORE spending a lot of money.

------------------------------------------------------------
If you do replace the converter ... don't guess on the wire size.
measure the wires diameter and approx length make sure they will allow the additional amperage ...

I agree completely, especially if you are going to use multiple batteries. I changed to a lithium converter and for me, I think it was a mistake.

The vast majority of data out there tells us only to charge lifepo4 to 80-90 percent and to discharge no lower than 20-10 percent SOC. This area of the SOC curve is where lifepo4 is happiest at. Said SOCs are at the "knee and elbow" of the lifepo4 charge curve. Being beyond or below those positions puts added stress on the battery chemistry. These stresses will shorten the total lifespan of the battery. Granted, for some users a shortened lifespan isn't a big deal for an already long lifespan battery. I get it!

[jcarenz]

Originally Posted by Thomaisheenjames

Hi.Plan on upgrading to lithium.My converter/charger is the standard wfco 55a.Was thinking of replacing with the wfco 55a autodetect as it should be an easy drop in.Think factory wire is 8ga .Would be very happy if i could get a 40/50 amp charge rate.Would appreciate any thoughts.Regards....Tommy.

If you have the standard WFCO LA charger, yes it will charge a LiFePO4 battery, but it will never put out the 14.4-14.6 volts needed to balance the cells .

Based on previous advice from @titanmike, i replaced my stock WFCO main board with "WFCO WF-8955LiS-MBA Converter/Charger, Main Board Assembly". It has a manual switch for Lead Acid or Lithium. They are hard to find but worth the look.

The WFCO Auto detect board is known to have issues. Go with something that you can force into a lithium mode. You will not regret it.

[TitanMike]

Originally Posted by PhilFromMaine

I agree completely, especially if you are going to use multiple batteries. I changed to a lithium converter and for me, I think it was a mistake.

The vast majority of data out there tells us only to charge lifepo4 to 80-90 percent and to discharge no lower than 20-10 percent SOC. This area of the SOC curve is where lifepo4 is happiest at. Said SOCs are at the "knee and elbow" of the lifepo4 charge curve. Being beyond or below those positions puts added stress on the battery chemistry. These stresses will shorten the total lifespan of the battery. Granted, for some users a shortened lifespan isn't a big deal for an already long lifespan battery. I get it!

Don't disagree that there is a lot of advice like that "out there" however one very important item this overlooks is cell top balance. If you have batteries with properly matched cells, with equal capacity and internal impedance, one MIGHT get away with this for a while but over time even the best matched cells will get out of balance with deep discharging and partial charging.

With more and more inexpensive (and even cheaply made) LiFepo4 batteries on the market I seriously doubt that the effort put forth by the premium battery manufacturers takes place so regular top balancing that, depending on the programming of the BMS, occurs ~the top 10% of the charge cycle but almost always ABOVE 14 Volts.

Over time one will notice a loss of capacity due to one or more cells charging quicker than the others and thus leaving some with even less than 90% SOC if using a converter/charger that doesn't finish charging to 14.2-14.6 volts.

There are workarounds for those using L/A programmed converters. As simple as a Lithium capable maintainer to finish topping off from shore power or solar charging with the controller set to a LiFePo4 charge profile.

BTW, this last week I met with some individuals from Battleborn (at Quartsite RV Show) and they are now verbally indicating expected life from their batteries to be 15 PLUS years. Their charging/storage recommendations remain "Charge to 100% and disconnect. Charge again to 100% at least once per year.

As for me, I keep my TT too busy to only charge within an 80% Soc range. I want to arrive at my boondocking site with full batteries. From there the Solar panels charge to 100% and when skies are heavily overcast, ditto for the generator.

Once again, my Battleborn's will very likely outlast me and still provide my "heirs" many more years of reliable service.