Should I use a standard converter charger for FLA battery and add a LiFePo4?

[Aussieguy]

may not be charging cause battery was FULL?

 

[hamrover]

You could also get a stand alone converter "deck mount" ... put it as close to battery as possible
this will remove any bad wiring that slows down the charging of the LFP
A new 120v piece of romex is much simpler and perform better than fooling around with the poor quality of some manufacturer's wiring

it also gives you a backup ... keep the original one in place and just disconnect it from breaker
If the new one eve played up would be a 5 minute job to resurrect the old one

you can go with a HIGHER amperage one too ... get a 55amp model
for faster lifepo4 charging

You know, I like to look at multiple options, so I am glad you mentioned this.

I kind of like the "deck mount" idea in theory. Are there any "cons" to this, and what are they?

Let's say I go with a deck mount. I am thinking I would want to look for one that has obviously will handle the LFP, and offer temperature compensation. The next question is, what do I do with the WFCO-8735-P power center and converter? It seems like I would just need to shut of breaker 5 (converter) on my power center, and then everything else would operate like usual?

 

[Aussieguy]

you leave the power center alone except for disconnecting the existing converter
just disconnect the 120v wires black one at the fuse white one on neutral bar


when disconnecting the breaker make sure there is not a second black wire coming out of the breaker
my water heater is also connected to converter...
AND if something else stops working you'll have to investigate if used a single wire and then split power off somewhere along the wire.

Power center ..... the 12v fuse panel will not know whether the 12v reaching it along the existing wires is being supplied by a battery or a stand alone....

LEAVE the existing converter in place.... it fits nicely and if the NEW one fails
you can re-attach the wiring to the old one until you get the other fixed

 

[Aussieguy]

PS
no cons other than being a bit more $$$ and running a bit of extra 120v wire

there may be more PRO's I have not mentioned but having it close to battery and not having to deal with line losses is the fastest bestest way to charge from generator

If you only use city power .... no real benefit as you normally plug in overnight or longer
you don't even need a battery if connected to shorepower and slides/jacks are in good condition
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My preference would be
1) add solar first...
it give more value for $$$ because you are actually upgrading the number of charging options

Solar extends the time you can travel without a really long extension cord
Unless you are permanently in one spot, most people sooner or later will get into the sun...
those that don't get a lot of sun.... check your vitamin D levels

If you are camping in winter .... more than likely you will have shorepower for better heat...
existing converter + a small charger will work fine


2) add a small 120v charger capable of topping up battery
if you not using it for weeks ... top it off and disconnect battery

3) Optimize the existing converter's wiring especially the negatives
even if you buy a AD version of the existing you'll still need to check the wiring

4) upgrade converter ... last option
If you use a generator a lot ..... make this FIRST option

 

[Riverguy42]

Li-ion does not need to be fully charged as is the case with lead acid, nor is it desirable to do so. In fact, it is better not to fully charge because a high voltage stresses the battery. Choosing a lower voltage threshold or eliminating the saturation charge altogether, prolongs battery life but this reduces the runtime.

He has LiFePO4 (Lithium ferro-phosphate) batteries. What you wrote above does not apply.

 

[RobbieH]

may not be charging cause battery was FULL?

I didn't see this until now. The battery was at 20ish percent at the time.

 

[Riverguy42]

the 3 stage
BULK mode appears to be a repair mode for desulfication etc

normal chargeing will be 13.6 which is good enough for charging a lifepo4 BUT will be slow
if you want generator charging look at replacing with a more modern converter

Sorry...but no.

In a multi-stage charging system, BULK stage is a "constant-current" mode intended to bring a Lead-Acid battery from <40% to a maximum of 60-70% rapidly -- without boiling the electrolyte.

Desulfate is not a stage, it is a maintenence mode, used occasionally (never a part of the normal charging process). Desulfation is a brief, high-voltage mode intended to carefully induce 'nucleate boiling' on the plates in FLA batteries ONLY. In really high-tech chargers, desulfation of FLAs is accomplished with a low-frequency 'square-wave' that works better than controlled boiling of the electrolyte.

For reference, in RV and Marine systems the three stages for 12v (six cell) FLA are:

1) Bulk (Constant Current, TIME LIMITED based on FLA battery AH capacity),
2) Absorption (constant voltage, current limited, 13.8v-14.2v) and
3) Float/Maintain (~13.2v, slightly above the 'chemical' cell voltage of 12.7 (2.12v/cell) but well below the 'gassing voltage', which critically depends on the battery temperature.

Actually, the second and third stages BOTH depend on the temperature of the battery, but float is the most potentially dangerous (especially in BOATS, where explosive hydrogen gas can be trapped).

The best FLA charging systems use a BTS (battery temp sensor) and adjust the Absorb and Float voltages automatically to prevent excessive hydrogen outgassing. For this reason, battery temperature sensors are REQUIRED by ABYC and the Coast Guard in boat battery chargers capable of >60A output.